document_title: Vehicle registration plates of Europe

question_text: what does aa on a license plate mean

question_tokens: what does aa on a license plate mean

text: Vehicle registration plates of Europe

text: Format[edit]

text: The common EU format of having a blue section on the extreme left with EU circle of stars and the country code was introduced by Council Regulation (EC) No 2411/98 of 3 November 1998[2] and entered into force on the 11 November 1998. It was based on a model registration plate which three member states had already introduced before: Ireland (1991),[3] Portugal (1992) [4] and Germany (1994).[5] Luxembourg plates had displayed the European Flag on the left part since 1988.

text:
The common design consists of a blue strip on the left side of the plate. This blue strip has the European flag symbol (twelve yellow stars), along with the country code of the member state in which the vehicle is registered. Danish plates have a small holographic strip to the right of the blue EU strip.
EU format plates are either white or yellow, on a plate wider than it is tall. Yellow registration plates are used both front and rear in Luxembourg and the Netherlands. In Gibraltar, the United Kingdom and Cyprus, yellow plates are used at the rear and white at the front. The UK use flat plastic plates (embossed metal plates are an option in the UK), as opposed to metal plates in most other European countries. A mixture of plastic or metal plates is permitted in France and Ireland. Plastic plates have earlier also been used in Sweden and Norway
Denmark and Hungary use yellow plates for vehicles registered as commercial vehicles and in Greece, Latvia, Lithuania and Sweden yellow plates are used for taxi vehicles. Belgium uses red characters and is the only country not to use the standard black-on-white or black-on-yellow combination; with the introduction of European-style plates in November 2010, a slightly darker shade of red was chosen (RAL 3003) to improve legibility. In Norway, cars with front seats only (used for cargo) have green plates with black characters.
The EU format is optional in Denmark,[6] Finland, the United Kingdom and also Cyprus. This is because of the way in which the Council Regulation implementing the EU Symbol (Regulation No. 2411/98) is drafted. It only requires states that have ratified the Vienna Convention of 1968 on road traffic to enforce the EU symbol.
Several non-EU European states have implemented similar formats, replacing the circle of stars with own symbols. Norway is an example of such state, issuing europlates with the Norwegian flag replacing the circle of stars. Iceland issues plates with the Icelandic flag above the country code on the left side. From those states that joined in the 2004 enlargement of the European Union Malta already used europlates, while Latvia, Poland and Lithuania had used EU number plates displaying the national flag before their accession, as did Bulgaria and Romania before their accession in 2007.
Turkey is not a member of the EU, however uses the blue European strip on the left of the plate as a member of European Customs Union (only member of the union without EU membership), with the country code (TR), but without the 12-EU stars sign. License plates consist of letters and digits in combinations of 99 AB 999, 99 A 9999, 99 ABC 99, 99 AB 9999 or 99 A 99999 where the first two digits show which province the vehicle is registered from. First two digits numbers go from 01 to 81 (as there are 81 provinces in Turkey) and each one is assigned to a province with alphabetical order e.g. 01 is the code of the province Adana or 34 is the code of the province Istanbul. All 81 provinces uses "01 AB 123" style plates initially until all combinations ran out, then the province starts to use 01 A 1234 then 01 ABC 12 etc. As a result, three largest provinces i.e. Istanbul, Ankara and İzmir are currently issuing 99 AB 9999 style plates since they used all combinations of previous series but the province Sivas for example, still issues 99 AB 999 plates as having a modest population and number of vehicles. 99 A 99999 series are not regular since they are only used in provinces where commercial vehicles are abundant e.g. Bursa to distinguish these vehicles there from passenger cars. Letters "I" and "O" are only used in the middle 01 ABC 12 series e.g. 34 YOC 34 or 06 TIL 56 to avoid confusion with numerals "1" and "0" respectively. Also some letters combinations like "PKK" are not issued due to their referring to political organizations or words likely to cause offence.

text: Common letter and digit systems between countries[edit]

text: Several countries have made efforts to avoid duplicating registration numbers used by other countries. Nevertheless, this is not completely successful and there are occasional difficulties for example in connection with parking fines and automatic speed cameras.

text:
Belgium (until 2010), Cyprus, Finland, Georgia (until 2014), Hungary, Lithuania, Malta, Sweden (since 1974), and Moldova (since 2014) each use combinations of first three letters and then three digits.
Bulgaria uses plate numbers in the form A[A]-0000-A[A], i.e. one or two letters representing the region, then four digits, then one or two more letters. All letters used are intersection of Latin and Cyrillic alphabet, i.e. A, B, C, E, H, K, M, O, P, T, X and Y.
Greece uses a combination of three letters (which are the intersection of Latin and Greek alphabet, i.e. A, B, E, Z, H, I, K, M, N, O, P, T, Y, X in Greek alphabetic order) and four numbers, in the form of AAA-0000, while Spain uses a four number-three letter combination, in the form of 0000 BBB (vowels and some maybe confusing consonants, like Ñ and Q, are not used)
Denmark and Norway use two letters and five digits (for trailers in Denmark two letters but just four digits). The plates look very similar, but Denmark has a red border around the plate. Use of the country code on the plate may mitigate this problem (Norway began using the system on 1 November 2006). Denmark has begun running out of combinations in this style and has now introduced combinations previously reserved for Faroe Islands for EU style number plates (which will use different letters than non-EU style plates).
The Netherlands and Portugal both use three groups of two characters (letters or numbers) in several sequences: AB-12-CD, 12-34-AB, 12-AB-34, AB-12-34, etc. However, Portuguese plates have a white background, while those of Netherlands (after 1978-01-01) have a yellow one, though both countries also use white letters on blue plates for classic cars. Furthermore, newer plates on Dutch vehicles only contain consonants, to avoid coincidental abbreviations or words. Also some sensitive letter combinations, such as SS or SD, are not used. The combination 'AA' is reserved for cars of the royal family. Dutch company registered bus, truck and/or minivan plates always start with a B or a V. Dutch taxis use blue registration plates. The number of new combinations ran out in 2008. By now, new registered cars in the Netherlands use the following format of two digits-three letters-one digit (12-ABC-3).
Belgium used the sequence ABC-123 between 1973 and 2008. When these combinations ran out in 2008, the inverse sequence 123-ABC was adopted, with the first plate in the new series issued on June 25, 2008. With the introduction of the European format on November 15, 2010, a seven-character combination 1-ABC-234 is used and the previous 123-ABC was discontinued. However, the six-character plates will remain valid and no date is set for their expiration yet. Since Belgian plates are linked to an owner rather than to a vehicle, these older plates are likely to remain in use for a considerable time. As a way to phase out the six-character plates, future vehicle subscriptions will only be possible on the seven-character plates.
Luxembourg plates use two letters and four digits AB 1234. Older series with only three digits (AB 123) or all-numeric plates with up to five digits are no longer issued but are still in use.
Current registrations allocated in Romania and the United Kingdom (where the registration contains two digits) are both of the form AB12 CDE). The Romanian rear plates are white whereas UK ones are yellow. There is also a difference in the spacing and the font. In 2015, Bucharest, the capital of Romania, adopted the form B 123 AAA, three digits and three letters, because the number of cars had risen.
Sweden. Until 1973/74 the Swedish pattern was one letter representing the län (county) where the car was first registered, followed by four or five digits. However, in the more populated län, a second letter became introduced over time. F.i. vehicles from southernmost county got the letter M + five digits, later also MA + five digits, MB + five digits etc. A problem was that the two northernmost counties had already been given two letters, the letter prefixes AC and BD, as the number of usable letters exceeded the number of counties. The ABC 123 system was introduced gradually from July 1973 until June 1974.
Slovakia uses AB 123CD and Croatia uses AB 123-CD (in both cases also other patterns are possible). Both countries use a coat of arms after first two letters, and the fonts and colors also look very similar. The plates can be easily distinguished by country code on the blue strip on left.
Montenegro and Serbia, currently not members of the EU, used the following system until 2007: MM 12-34, MM 123-45 or MM 123-456 (MM being two letter abbreviation of municipality), and having state flag (of former Yugoslavia, later Serbia and Montenegro) between municipality and numbers. Montenegro left that system in 2007, and introduced new format: MM AB 123, with Montenegrin coat of arms in circular shape between municipality and letter sequence. Blue strip with MNE country code is placed in the left side, with vacant place for EU stars, in case of joining the Union. Serbia also uses new system with blue strip country code SRB: MM 123-AB and MM 1234-AB, with Serbian coat of arms between municipality and number sequence. The first two letters on the Serbian plates represent the municipality code, written in Latin letters, and repeated in Cyrillic characters with small letters under the coat of arms. The following system is used for taxi vehicles: BG 123 TX or BG 1234 TX and recently even BG 12345 TX, where a TX combination is reserved for this purpose only (another taxi vehicles have private vehicle plates). Since 2017, Serbia stopped issuing plates with last two letters containing W, Q, Y, X (except TX), Č, Ć, Š, Ž, and Đ, however Serbian Latin letters with diacritics are still used to mark the municipality code, like ČA for Čačak or ŠA for Šabac.

text: Differing numbering systems[edit]

text: Individual European countries use differing numbering schemes and text fonts:

text:
Most countries, including Austria, Bulgaria, Croatia, the Czech Republic, Germany, Greece, Ireland, Macedonia, Montenegro, Norway, Poland, Romania, Serbia, Slovakia, Slovenia and Switzerland (formerly also Sweden-until 1974, Italy—until 1994, Bosnia and Herzegovina—until 1998, Lithuania and Spain —until 2000, Estonia -until 2004 and Albania —until 2011, of former countries also East Germany -until 1990, Soviet Union -until 1991, Czechoslovakia -until 1993, Yugoslavia -until 1998 and Serbia and Montenegro -until 2011), have systems in which there is a direct link between a letter or letters appearing on the plate and the town or district where the plate was issued (e.g. "B" and "M" in Germany for Berlin and Munich, "TN" and "ZV" in Slovakia for Trenčín and Zvolen, "BG" and "KG" in Serbia for Belgrade and Kragujevac and "AX" and "KY" in Greece for Achaea and Corfu). Some countries, including Austria, Germany, Slovenia, and Switzerland, even include a regional or municipal coat of arms on the plate, but Croatia, Montenegro, Serbia and Slovakia includes a national coat of arms. In Ireland, all plates have the name of the county of registration in Irish in smaller letters on the top.
France (until 2009), Turkey and Russia (since October 2013) use a system with an indirect number relation to the car's place of registration.
The UK uses a system based on the region where the car was first registered and the date of registration, for example CA52 GJK, where by the "C" stands for Wales (the name of that country in Welsh being Cymru), the "A" stands for Cardiff (the letters A-O assigned to the city), and the "52" means that the car was registered in the year 2002, in or after September.
Belgium, Bosnia and Herzegovina, Denmark, Iceland, Estonia (after 2004), Finland, Hungary, Latvia, Lithuania (after 2000), Luxembourg, the Netherlands, Portugal and Sweden (after 1974) use plates that do not denote location where the car is registered. Since 2000 Spain no longer uses province codes on plates but codes like 'B' for Barcelona or 'M' for Madrid can still be seen, for cars registered before that date. Italy, also, doesn't have used the province codes on plates between 1994 and 1999.
Italy, since 1999, has added a blue strip on either side. On the right one are the two digits of the year when the plate was issued (e.g. "99", "05", "08") and below that there may be an optional two-letter code for the province, such as "MO" for the Province of Modena. Albania and France have adopted similar formats.
Irish license plates also contain the year in which the vehicle was registered. A car registered in 2008 would have the format 08-XX-XXXX. In 2013, this was updated to specify which half of the year the registration occurred. So from January to June, the license plate would show (for 2013) 131-XX-XXXX, whereas from June to December, the plate instead shows 132-XX-XXXX.

text: Cross-border traffic[edit]

text: Vehicles in cross-border traffic are obliged to display a distinguishing sign of the country of registration on the rear of the vehicle. This sign may either be placed separately from the registration plate or may be incorporated into the vehicle registration plate (such as the EU strip).

text: The physical requirements for the separate sign are defined in Annex 3 of the Vienna Convention on Road Traffic, which states that the letters shall be in black on a white background having the shape of an ellipse with the major axis horizontal. The distinguishing sign should not be affixed in such a way that it could be confused with the registration number or impair its legibility.

text: When the distinguishing sign is incorporated into the registration plate, it must also appear on the front registration plate of the vehicle, and may be supplemented with the flag or emblem of the national state, or the emblem of the regional economic integration organization to which the country belongs. The distinguishing sign should be displayed on the far left or far right on the registration plate. When a symbol/flag/emblem is also displayed, the distinguishing sign shall obligatory be placed on the far left on the plate. The distinguishing sign shall be positioned so to be easy identifiable and so that it cannot be confused with the registration number or impair its legibility. The distinguishing sign shall therefore be at least a different color from the registration number, or have a different background color to that reserved for the registration number, or be clearly separated from the registration number, preferably with a line.[7]

text: Vehicles with EU number plates do not need to display the white oval international vehicle registration code while within the European Economic Area. Because of the way in which the Council Regulation implementing the EU Symbol (Regulation No. 2411/98) is drafted, the EU format is optional in Denmark, Finland, the United Kingdom and Cyprus. The regulation only requires states that have ratified the Vienna Convention of 1968 on road traffic to enforce the EU symbol. This can be seen in Article 3, which reads: "Member States requiring vehicles registered in another Member State to display a distinguishing registration sign when they are being driven on their territory shall recognise the distinguishing [EU Symbol] sign"

text: The 'requirement', "to display a distinguishing registration sign" is derived directly from Article 37 of the 1968 Vienna Convention on Road Traffic (this is actually stated in preamble (3) of Regulation 2411/98). So in order for Reg 2411/98 to apply, the state must have ratified the 1968 Convention. Since Denmark, Finland and the UK have not ratified it, Regulation 2411/98 technically does not apply and therefore the EU symbol is not a mandatory requirement in those states.

text: Countries[edit]

text: Dependencies, partially recognized and disputed territories[edit]

text: List[edit]

text: Vehicle registration plates of each country are described in the following table:

text: Countries [8][edit]

text:
Country
Code
Example

 Albania
AL

 Andorra
AND

 Armenia
AM

 Austria
A

 Azerbaijan
AZ

 Belarus
BY

 Belgium
B

 Bosnia and Herzegovina
BIH

 Bulgaria
BG

 Croatia
HR

 Cyprus
CY

 Czech Republic
CZ

 Denmark
DK

 Estonia
EST

 Finland
FIN

 France
F

 Georgia
GE

 Germany
D

 Greece
GR

 Hungary
H

 Iceland
IS

 Ireland
IRL

 Italy
I

 Latvia
LV

 Liechtenstein
FL

 Lithuania
LT

 Luxembourg
L

 Macedonia
MK

 Malta
M

 Moldova
MD

 Monaco
MC

 Montenegro
MNE

 Netherlands
NL

 Norway
N

 Poland
PL

 Portugal
P

 Romania
RO

 Russia
RUS

 San Marino
RSM

 Serbia
SRB

 Slovakia
SK

 Slovenia
SLO

 Spain
E

 Sweden
S

  Switzerland
CH

 Turkey
TR

 Ukraine
UA

 United Kingdom
GB

  Vatican City
V

text:
Territory
Code
Example

 Abkhazia
ABH

 Åland Islands
AX

 Gibraltar
GBZ

 Faroe Islands
FO

 Guernsey
GBG

 Isle of Man
GBM

 Jersey
GBJ

 Kosovo[a]
RKS

 Northern Cyprus
CY

 South Ossetia
RSO

 Transnistria
PMR

text: Motorcycle plates[edit]

text: These are used for motorcycles and vehicles where mounting space is an issue, such as taxis which display their licence plate beside the registration plate, and vehicles imported from countries where the mounting space was not originally designed to take European-sized plates (e.g. USA).

text: Countries[edit]

text:
Country
Code
Example

 Belarus
BY

 France
F

 Germany
D

 Italy
I

 Latvia
LV

 Macedonia
MK

 Malta
M

 Moldova
MD

 Monaco
MC

 Montenegro
MD

 Norway
N

 Poland
PL

 Serbia
SRB

 Spain
E

 Sweden
S

 Turkey
TR

 Ukraine
UA

 United Kingdom
GB

text:
Territory
Code
Example

 Kosovo[a]
RKS

 South Ossetia
RSO

 Transnistria
PMR


document_title: Cell nucleus

question_text: what is the advantage of enclosing dna material in the nucleus

root

text: Cell nucleus

text: History

text: The nucleus was the first organelle to be discovered. What is most likely the oldest preserved drawing dates back to the early microscopist Antonie van Leeuwenhoek (1632–1723). He observed a "lumen", the nucleus, in the red blood cells of salmon.[2] Unlike mammalian red blood cells, those of other vertebrates still contain nuclei.

tag: p

text: The nucleus was also described by Franz Bauer in 1804[3] and in more detail in 1831 by Scottish botanist Robert Brown in a talk at the Linnean Society of London. Brown was studying orchids under microscope when he observed an opaque area, which he called the "areola" or "nucleus", in the cells of the flower's outer layer.[4]

text: He did not suggest a potential function. In 1838, Matthias Schleiden proposed that the nucleus plays a role in generating cells, thus he introduced the name "cytoblast" (cell builder). He believed that he had observed new cells assembling around "cytoblasts". Franz Meyen was a strong opponent of this view, having already described cells multiplying by division and believing that many cells would have no nuclei. The idea that cells can be generated de novo, by the "cytoblast" or otherwise, contradicted work by Robert Remak (1852) and Rudolf Virchow (1855) who decisively propagated the new paradigm that cells are generated solely by cells ("Omnis cellula e cellula"). The function of the nucleus remained unclear.[5]

text: Between 1877 and 1878, Oscar Hertwig published several studies on the fertilization of sea urchin eggs, showing that the nucleus of the sperm enters the oocyte and fuses with its nucleus. This was the first time it was suggested that an individual develops from a (single) nucleated cell. This was in contradiction to Ernst Haeckel's theory that the complete phylogeny of a species would be repeated during embryonic development, including generation of the first nucleated cell from a "monerula", a structureless mass of primordial mucus ("Urschleim"). Therefore, the necessity of the sperm nucleus for fertilization was discussed for quite some time. However, Hertwig confirmed his observation in other animal groups, including amphibians and molluscs. Eduard Strasburger produced the same results for plants in 1884. This paved the way to assign the nucleus an important role in heredity. In 1873, August Weismann postulated the equivalence of the maternal and paternal germ cells for heredity. The function of the nucleus as carrier of genetic information became clear only later, after mitosis was discovered and the Mendelian rules were rediscovered at the beginning of the 20th century; the chromosome theory of heredity was therefore developed.[5]

text: Structures

text: The nucleus is the largest cellular organelle in animal cells.[6] In mammalian cells, the average diameter of the nucleus is approximately 6 micrometres (µm), which occupies about 10% of the total cell volume.[7] The viscous liquid within it is called nucleoplasm (or karyolymph), and is similar in composition to the cytosol found outside the nucleus.[8] It appears as a dense, roughly spherical or irregular organelle. The composition by dry weight of the nucleus is approximately: DNA 9%, RNA 1%, Histone Protein 11%, Residual Protein 14%, Acidic Proteins 65%.

text: Nuclear envelope and pores

text:
The eukaryotic cell nucleus. Visible in this diagram are the ribosome-studded double membranes of the nuclear envelope, the DNA (complexed as chromatin), and the nucleolus. Within the cell nucleus is a viscous liquid called nucleoplasm, similar to the cytoplasm found outside the nucleus.

A cross section of a nuclear pore on the surface of the nuclear envelope (1). Other diagram labels show (2) the outer ring, (3) spokes, (4) basket, and (5) filaments.

tag: table

text: The nuclear envelope, otherwise known as nuclear membrane, consists of two cellular membranes, an inner and an outer membrane, arranged parallel to one another and separated by 10 to 50 nanometres (nm). The nuclear envelope completely encloses the nucleus and separates the cell's genetic material from the surrounding cytoplasm, serving as a barrier to prevent macromolecules from diffusing freely between the nucleoplasm and the cytoplasm.[9] The outer nuclear membrane is continuous with the membrane of the rough endoplasmic reticulum (RER), and is similarly studded with ribosomes.[9] The space between the membranes is called the perinuclear space and is continuous with the RER lumen.

text: Nuclear pores, which provide aqueous channels through the envelope, are composed of multiple proteins, collectively referred to as nucleoporins. The pores are about 125 million daltons in molecular weight and consist of around 50 (in yeast) to several hundred proteins (in vertebrates).[6] The pores are 100 nm in total diameter; however, the gap through which molecules freely diffuse is only about 9 nm wide, due to the presence of regulatory systems within the center of the pore. This size selectively allows the passage of small water-soluble molecules while preventing larger molecules, such as nucleic acids and larger proteins, from inappropriately entering or exiting the nucleus. These large molecules must be actively transported into the nucleus instead. The nucleus of a typical mammalian cell will have about 3000 to 4000 pores throughout its envelope,[10] each of which contains an eightfold-symmetric ring-shaped structure at a position where the inner and outer membranes fuse.[11] Attached to the ring is a structure called the nuclear basket that extends into the nucleoplasm, and a series of filamentous extensions that reach into the cytoplasm. Both structures serve to mediate binding to nuclear transport proteins.[6]

text: Most proteins, ribosomal subunits, and some DNAs are transported through the pore complexes in a process mediated by a family of transport factors known as karyopherins. Those karyopherins that mediate movement into the nucleus are also called importins, whereas those that mediate movement out of the nucleus are called exportins. Most karyopherins interact directly with their cargo, although some use adaptor proteins.[12] Steroid hormones such as cortisol and aldosterone, as well as other small lipid-soluble molecules involved in intercellular signaling, can diffuse through the cell membrane and into the cytoplasm, where they bind nuclear receptor proteins that are trafficked into the nucleus. There they serve as transcription factors when bound to their ligand; in the absence of a ligand, many such receptors function as histone deacetylases that repress gene expression.[6]

text: Nuclear lamina

text: In animal cells, two networks of intermediate filaments provide the nucleus with mechanical support: The nuclear lamina forms an organized meshwork on the internal face of the envelope, while less organized support is provided on the cytosolic face of the envelope. Both systems provide structural support for the nuclear envelope and anchoring sites for chromosomes and nuclear pores.[7]

text: The nuclear lamina is composed mostly of lamin proteins. Like all proteins, lamins are synthesized in the cytoplasm and later transported to the nucleus interior, where they are assembled before being incorporated into the existing network of nuclear lamina.[13][14] Lamins found on the cytosolic face of the membrane, such as emerin and nesprin, bind to the cytoskeleton to provide structural support. Lamins are also found inside the nucleoplasm where they form another regular structure, known as the nucleoplasmic veil,[15] that is visible using fluorescence microscopy. The actual function of the veil is not clear, although it is excluded from the nucleolus and is present during interphase.[16] Lamin structures that make up the veil, such as LEM3, bind chromatin and disrupting their structure inhibits transcription of protein-coding genes.[17]

text: Like the components of other intermediate filaments, the lamin monomer contains an alpha-helical domain used by two monomers to coil around each other, forming a dimer structure called a coiled coil. Two of these dimer structures then join side by side, in an antiparallel arrangement, to form a tetramer called a protofilament. Eight of these protofilaments form a lateral arrangement that is twisted to form a ropelike filament. These filaments can be assembled or disassembled in a dynamic manner, meaning that changes in the length of the filament depend on the competing rates of filament addition and removal.[7]

text: Mutations in lamin genes leading to defects in filament assembly cause a group of rare genetic disorders known as laminopathies. The most notable laminopathy is the family of diseases known as progeria, which causes the appearance of premature aging in its sufferers. The exact mechanism by which the associated biochemical changes give rise to the aged phenotype is not well understood.[18]

text: Chromosomes

text: The cell nucleus contains the majority of the cell's genetic material in the form of multiple linear DNA molecules organized into structures called chromosomes. Each human cell contains roughly two meters of DNA. During most of the cell cycle these are organized in a DNA-protein complex known as chromatin, and during cell division the chromatin can be seen to form the well-defined chromosomes familiar from a karyotype. A small fraction of the cell's genes are located instead in the mitochondria.

text: There are two types of chromatin. Euchromatin is the less compact DNA form, and contains genes that are frequently expressed by the cell.[19] The other type, heterochromatin, is the more compact form, and contains DNA that is infrequently transcribed. This structure is further categorized into facultative heterochromatin, consisting of genes that are organized as heterochromatin only in certain cell types or at certain stages of development, and constitutive heterochromatin that consists of chromosome structural components such as telomeres and centromeres.[20] During interphase the chromatin organizes itself into discrete individual patches,[21] called chromosome territories.[22] Active genes, which are generally found in the euchromatic region of the chromosome, tend to be located towards the chromosome's territory boundary.[23]

text: Antibodies to certain types of chromatin organization, in particular, nucleosomes, have been associated with a number of autoimmune diseases, such as systemic lupus erythematosus.[24] These are known as anti-nuclear antibodies (ANA) and have also been observed in concert with multiple sclerosis as part of general immune system dysfunction.[25] As in the case of progeria, the role played by the antibodies in inducing the symptoms of autoimmune diseases is not obvious.

text: Nucleolus

text: The nucleolus is a discrete densely stained structure found in the nucleus. It is not surrounded by a membrane, and is sometimes called a suborganelle. It forms around tandem repeats of rDNA, DNA coding for ribosomal RNA (rRNA). These regions are called nucleolar organizer regions (NOR). The main roles of the nucleolus are to synthesize rRNA and assemble ribosomes. The structural cohesion of the nucleolus depends on its activity, as ribosomal assembly in the nucleolus results in the transient association of nucleolar components, facilitating further ribosomal assembly, and hence further association. This model is supported by observations that inactivation of rDNA results in intermingling of nucleolar structures.[26]

text: In the first step of ribosome assembly, a protein called RNA polymerase I transcribes rDNA, which forms a large pre-rRNA precursor. This is cleaved into the subunits 5.8S, 18S, and 28S rRNA.[27] The transcription, post-transcriptional processing, and assembly of rRNA occurs in the nucleolus, aided by small nucleolar RNA (snoRNA) molecules, some of which are derived from spliced introns from messenger RNAs encoding genes related to ribosomal function. The assembled ribosomal subunits are the largest structures passed through the nuclear pores.[6]

text: When observed under the electron microscope, the nucleolus can be seen to consist of three distinguishable regions: the innermost fibrillar centers (FCs), surrounded by the dense fibrillar component (DFC), which in turn is bordered by the granular component (GC). Transcription of the rDNA occurs either in the FC or at the FC-DFC boundary, and, therefore, when rDNA transcription in the cell is increased, more FCs are detected. Most of the cleavage and modification of rRNAs occurs in the DFC, while the latter steps involving protein assembly onto the ribosomal subunits occur in the GC.[27]

text: Other subnuclear bodies

text:
Subnuclear structure sizes

Structure name
Structure diameter

Cajal bodies
0.2–2.0 µm
[28]

Clastosomes
0.2-0.5 µm
[29]

PIKA
5 µm
[30]

PML bodies
0.2–1.0 µm
[31]

Paraspeckles
0.2–1.0 µm
[32]

Speckles
20–25 nm
[30]

text: Besides the nucleolus, the nucleus contains a number of other non-membrane-delineated bodies. These include Cajal bodies, Gemini of coiled bodies, polymorphic interphase karyosomal association (PIKA), promyelocytic leukaemia (PML) bodies, paraspeckles, and splicing speckles. Although little is known about a number of these domains, they are significant in that they show that the nucleoplasm is not a uniform mixture, but rather contains organized functional subdomains.[31]

text: Other subnuclear structures appear as part of abnormal disease processes. For example, the presence of small intranuclear rods has been reported in some cases of nemaline myopathy. This condition typically results from mutations in actin, and the rods themselves consist of mutant actin as well as other cytoskeletal proteins.[33]

text: Cajal bodies and gems

text: A nucleus typically contains between 1 and 10 compact structures called Cajal bodies or coiled bodies (CB), whose diameter measures between 0.2 µm and 2.0 µm depending on the cell type and species.[28] When seen under an electron microscope, they resemble balls of tangled thread[30] and are dense foci of distribution for the protein coilin.[34] CBs are involved in a number of different roles relating to RNA processing, specifically small nucleolar RNA (snoRNA) and small nuclear RNA (snRNA) maturation, and histone mRNA modification.[28]

text: Similar to Cajal bodies are Gemini of Cajal bodies, or gems, whose name is derived from the Gemini constellation in reference to their close "twin" relationship with CBs. Gems are similar in size and shape to CBs, and in fact are virtually indistinguishable under the microscope.[34] Unlike CBs, gems do not contain small nuclear ribonucleoproteins (snRNPs), but do contain a protein called survival of motor neuron (SMN) whose function relates to snRNP biogenesis. Gems are believed to assist CBs in snRNP biogenesis,[35] though it has also been suggested from microscopy evidence that CBs and gems are different manifestations of the same structure.[34] Later ultrastructural studies have shown gems to be twins of Cajal bodies with the difference being in the coilin component; Cajal bodies are SMN positive and coilin positive, and gems are SMN positive and coilin negative.[36]

text: RAFA and PTF domains

text: RAFA domains, or polymorphic interphase karyosomal associations, were first described in microscopy studies in 1991. Their function remains unclear, though they were not thought to be associated with active DNA replication, transcription, or RNA processing.[37] They have been found to often associate with discrete domains defined by dense localization of the transcription factor PTF, which promotes transcription of small nuclear RNA (snRNA).[38]

text: PML bodies

text: Promyelocytic leukaemia bodies (PML bodies) are spherical bodies found scattered throughout the nucleoplasm, measuring around 0.1–1.0 µm. They are known by a number of other names, including nuclear domain 10 (ND10), Kremer bodies, and PML oncogenic domains. PML bodies are named after one of their major components, the promyelocytic leukemia protein (PML). They are often seen in the nucleus in association with Cajal bodies and cleavage bodies.[31] PML bodies belong to the nuclear matrix, an ill-defined super-structure of the nucleus proposed to anchor and regulate many nuclear functions, including DNA replication, transcription, or epigenetic silencing.[39] The PML protein is the key organizer of these domains that recruits an ever-growing number of proteins, whose only common known feature to date is their ability to be SUMOylated. Yet, pml-/- mice (which have their PML gene deleted) cannot assemble nuclear bodies, develop normally and live well, demonstrating that PML bodies are dispensable for most basic biological functions.[39]

text: Splicing speckles

text: Speckles are subnuclear structures that are enriched in pre-messenger RNA splicing factors and are located in the interchromatin regions of the nucleoplasm of mammalian cells. At the fluorescence-microscope level they appear as irregular, punctate structures, which vary in size and shape, and when examined by electron microscopy they are seen as clusters of interchromatin granules. Speckles are dynamic structures, and both their protein and RNA-protein components can cycle continuously between speckles and other nuclear locations, including active transcription sites. Studies on the composition, structure and behaviour of speckles have provided a model for understanding the functional compartmentalization of the nucleus and the organization of the gene-expression machinery[40] splicing snRNPs[41][42] and other splicing proteins necessary for pre-mRNA processing.[43] Because of a cell's changing requirements, the composition and location of these bodies changes according to mRNA transcription and regulation via phosphorylation of specific proteins.[44] The splicing speckles are also known as nuclear speckles (nuclear specks), splicing factor compartments (SF compartments), interchromatin granule clusters (IGCs), B snurposomes.[45] B snurposomes are found in the amphibian oocyte nuclei and in Drosophila melanogaster embryos. B snurposomes appear alone or attached to the Cajal bodies in the electron micrographs of the amphibian nuclei.[46] IGCs function as storage sites for the splicing factors.[47]

text: Paraspeckles

text: Discovered by Fox et al. in 2002, paraspeckles are irregularly shaped compartments in the nucleus' interchromatin space.[48] First documented in HeLa cells, where there are generally 10–30 per nucleus,[49] paraspeckles are now known to also exist in all human primary cells, transformed cell lines, and tissue sections.[50] Their name is derived from their distribution in the nucleus; the "para" is short for parallel and the "speckles" refers to the splicing speckles to which they are always in close proximity.[49]

text: Paraspeckles are dynamic structures that are altered in response to changes in cellular metabolic activity. They are transcription dependent[48] and in the absence of RNA Pol II transcription, the paraspeckle disappears and all of its associated protein components (PSP1, p54nrb, PSP2, CFI(m)68, and PSF) form a crescent shaped perinucleolar cap in the nucleolus. This phenomenon is demonstrated during the cell cycle. In the cell cycle, paraspeckles are present during interphase and during all of mitosis except for telophase. During telophase, when the two daughter nuclei are formed, there is no RNA Pol II transcription so the protein components instead form a perinucleolar cap.[50]

text: Perichromatin fibrils

text: Perichromatin fibrils are visible only under electron microscope. They are located next to the transcriptionally active chromatin and are hypothesized to be the sites of active pre-mRNA processing.[47]

text: Clastosome

text: Clastosomes are small nuclear bodies (0.2-0.5 µm) described as donut-shaped due to the peripheral capsule around these bodies.[29] This name is derived from the Greek klastos, broken and soma, body.[29] Clastosomes are not typically present in normal cells, making them hard to detect. They form under high proteolysis conditions within the nucleus and degrade once there is a decrease in activity or if cells are treated with proteasome inhibitors.[29][51] The scarcity of clastosomes in cells indicates that they are not required for proteasome function.[52] Osmotic stress has also been shown to cause the formation of clastosomes. [53] These nuclear bodies contain catalytic and regulatory sub-units of the proteasome and its substrates, indicating that clastosomes are sites for degrading proteins.[52]

text: The Clastosome would be an important addition to the ‘Cell Nucleus’ Wiki page because it plays a role in cell function. With further research, we may discover that this nuclear body has a more influential job in cell function than what is already known. [29]

text: Function

text: The nucleus provides a site for genetic transcription that is segregated from the location of translation in the cytoplasm, allowing levels of gene regulation that are not available to prokaryotes. The main function of the cell nucleus is to control gene expression and mediate the replication of DNA during the cell cycle.

text: The nucleus is an organelle found in eukaryotic cells. Inside its fully enclosed nuclear membrane, it contains the majority of the cell's genetic material. This material is organized as DNA molecules, along with a variety of proteins, to form chromosomes.

text: Cell compartmentalization

text: The nuclear envelope allows the nucleus to control its contents, and separate them from the rest of the cytoplasm where necessary. This is important for controlling processes on either side of the nuclear membrane. In most cases where a cytoplasmic process needs to be restricted, a key participant is removed to the nucleus, where it interacts with transcription factors to downregulate the production of certain enzymes in the pathway. This regulatory mechanism occurs in the case of glycolysis, a cellular pathway for breaking down glucose to produce energy. Hexokinase is an enzyme responsible for the first the step of glycolysis, forming glucose-6-phosphate from glucose. At high concentrations of fructose-6-phosphate, a molecule made later from glucose-6-phosphate, a regulator protein removes hexokinase to the nucleus,[54] where it forms a transcriptional repressor complex with nuclear proteins to reduce the expression of genes involved in glycolysis.[55]

text: In order to control which genes are being transcribed, the cell separates some transcription factor proteins responsible for regulating gene expression from physical access to the DNA until they are activated by other signaling pathways. This prevents even low levels of inappropriate gene expression. For example, in the case of NF-κB-controlled genes, which are involved in most inflammatory responses, transcription is induced in response to a signal pathway such as that initiated by the signaling molecule TNF-α, binds to a cell membrane receptor, resulting in the recruitment of signalling proteins, and eventually activating the transcription factor NF-κB. A nuclear localisation signal on the NF-κB protein allows it to be transported through the nuclear pore and into the nucleus, where it stimulates the transcription of the target genes.[7]

text: The compartmentalization allows the cell to prevent translation of unspliced mRNA.[56] Eukaryotic mRNA contains introns that must be removed before being translated to produce functional proteins. The splicing is done inside the nucleus before the mRNA can be accessed by ribosomes for translation. Without the nucleus, ribosomes would translate newly transcribed (unprocessed) mRNA, resulting in malformed and nonfunctional proteins.

text: Gene expression

text: Gene expression first involves transcription, in which DNA is used as a template to produce RNA. In the case of genes encoding proteins, that RNA produced from this process is messenger RNA (mRNA), which then needs to be translated by ribosomes to form a protein. As ribosomes are located outside the nucleus, mRNA produced needs to be exported.[57]

text: Since the nucleus is the site of transcription, it also contains a variety of proteins that either directly mediate transcription or are involved in regulating the process. These proteins include helicases, which unwind the double-stranded DNA molecule to facilitate access to it, RNA polymerases, which bind to the DNA promoter to synthesize the growing RNA molecule, topoisomerases, which change the amount of supercoiling in DNA, helping it wind and unwind, as well as a large variety of transcription factors that regulate expression.[58]

text: Processing of pre-mRNA

text: Newly synthesized mRNA molecules are known as primary transcripts or pre-mRNA. They must undergo post-transcriptional modification in the nucleus before being exported to the cytoplasm; mRNA that appears in the cytoplasm without these modifications is degraded rather than used for protein translation. The three main modifications are 5' capping, 3' polyadenylation, and RNA splicing. While in the nucleus, pre-mRNA is associated with a variety of proteins in complexes known as heterogeneous ribonucleoprotein particles (hnRNPs). Addition of the 5' cap occurs co-transcriptionally and is the first step in post-transcriptional modification. The 3' poly-adenine tail is only added after transcription is complete.

text: RNA splicing, carried out by a complex called the spliceosome, is the process by which introns, or regions of DNA that do not code for protein, are removed from the pre-mRNA and the remaining exons connected to re-form a single continuous molecule. This process normally occurs after 5' capping and 3' polyadenylation but can begin before synthesis is complete in transcripts with many exons.[6] Many pre-mRNAs, including those encoding antibodies, can be spliced in multiple ways to produce different mature mRNAs that encode different protein sequences. This process is known as alternative splicing, and allows production of a large variety of proteins from a limited amount of DNA.

text: Dynamics and regulation

text: Nuclear transport

text: The entry and exit of large molecules from the nucleus is tightly controlled by the nuclear pore complexes. Although small molecules can enter the nucleus without regulation,[59] macromolecules such as RNA and proteins require association karyopherins called importins to enter the nucleus and exportins to exit. "Cargo" proteins that must be translocated from the cytoplasm to the nucleus contain short amino acid sequences known as nuclear localization signals, which are bound by importins, while those transported from the nucleus to the cytoplasm carry nuclear export signals bound by exportins. The ability of importins and exportins to transport their cargo is regulated by GTPases, enzymes that hydrolyze the molecule guanosine triphosphate to release energy. The key GTPase in nuclear transport is Ran, which can bind either GTP or GDP (guanosine diphosphate), depending on whether it is located in the nucleus or the cytoplasm. Whereas importins depend on RanGTP to dissociate from their cargo, exportins require RanGTP in order to bind to their cargo.[12]

text: Nuclear import depends on the importin binding its cargo in the cytoplasm and carrying it through the nuclear pore into the nucleus. Inside the nucleus, RanGTP acts to separate the cargo from the importin, allowing the importin to exit the nucleus and be reused. Nuclear export is similar, as the exportin binds the cargo inside the nucleus in a process facilitated by RanGTP, exits through the nuclear pore, and separates from its cargo in the cytoplasm.

text: Specialized export proteins exist for translocation of mature mRNA and tRNA to the cytoplasm after post-transcriptional modification is complete. This quality-control mechanism is important due to these molecules' central role in protein translation. Mis-expression of a protein due to incomplete excision of exons or mis-incorporation of amino acids could have negative consequences for the cell; thus, incompletely modified RNA that reaches the cytoplasm is degraded rather than used in translation.[6]

text: Assembly and disassembly

text: During its lifetime, a nucleus may be broken down or destroyed, either in the process of cell division or as a consequence of apoptosis (the process of programmed cell death). During these events, the structural components of the nucleus — the envelope and lamina — can be systematically degraded. In most cells, the disassembly of the nuclear envelope marks the end of the prophase of mitosis. However, this disassembly of the nucleus is not a universal feature of mitosis and does not occur in all cells. Some unicellular eukaryotes (e.g., yeasts) undergo so-called closed mitosis, in which the nuclear envelope remains intact. In closed mitosis, the daughter chromosomes migrate to opposite poles of the nucleus, which then divides in two. The cells of higher eukaryotes, however, usually undergo open mitosis, which is characterized by breakdown of the nuclear envelope. The daughter chromosomes then migrate to opposite poles of the mitotic spindle, and new nuclei reassemble around them.

text: At a certain point during the cell cycle in open mitosis, the cell divides to form two cells. In order for this process to be possible, each of the new daughter cells must have a full set of genes, a process requiring replication of the chromosomes as well as segregation of the separate sets. This occurs by the replicated chromosomes, the sister chromatids, attaching to microtubules, which in turn are attached to different centrosomes. The sister chromatids can then be pulled to separate locations in the cell. In many cells, the centrosome is located in the cytoplasm, outside the nucleus; the microtubules would be unable to attach to the chromatids in the presence of the nuclear envelope.[60] Therefore, the early stages in the cell cycle, beginning in prophase and until around prometaphase, the nuclear membrane is dismantled.[15] Likewise, during the same period, the nuclear lamina is also disassembled, a process regulated by phosphorylation of the lamins by protein kinases such as the CDC2 protein kinase.[61] Towards the end of the cell cycle, the nuclear membrane is reformed, and around the same time, the nuclear lamina are reassembled by dephosphorylating the lamins.[61]

text: However, in dinoflagellates, the nuclear envelope remains intact, the centrosomes are located in the cytoplasm, and the microtubules come in contact with chromosomes, whose centromeric regions are incorporated into the nuclear envelope (the so-called closed mitosis with extranuclear spindle). In many other protists (e.g., ciliates, sporozoans) and fungi, the centrosomes are intranuclear, and their nuclear envelope also does not disassemble during cell division.

text: Apoptosis is a controlled process in which the cell's structural components are destroyed, resulting in death of the cell. Changes associated with apoptosis directly affect the nucleus and its contents, for example, in the condensation of chromatin and the disintegration of the nuclear envelope and lamina. The destruction of the lamin networks is controlled by specialized apoptotic proteases called caspases, which cleave the lamin proteins and, thus, degrade the nucleus' structural integrity. Lamin cleavage is sometimes used as a laboratory indicator of caspase activity in assays for early apoptotic activity.[15] Cells that express mutant caspase-resistant lamins are deficient in nuclear changes related to apoptosis, suggesting that lamins play a role in initiating the events that lead to apoptotic degradation of the nucleus.[15] Inhibition of lamin assembly itself is an inducer of apoptosis.[62]

text: The nuclear envelope acts as a barrier that prevents both DNA and RNA viruses from entering the nucleus. Some viruses require access to proteins inside the nucleus in order to replicate and/or assemble. DNA viruses, such as herpesvirus replicate and assemble in the cell nucleus, and exit by budding through the inner nuclear membrane. This process is accompanied by disassembly of the lamina on the nuclear face of the inner membrane.[15]

text: Disease-related dynamics

text: Initially, it has been suspected that immunoglobulins in general and autoantibodies in particular do not enter the nucleus. Now there is a body of evidence that under pathological conditions (e.g. lupus erythematosus) IgG can enter the nucleus.[63]

text: Nuclei per cell

text: Most eukaryotic cell types usually have a single nucleus, but some have no nuclei, while others have several. This can result from normal development, as in the maturation of mammalian red blood cells, or from faulty cell division.

text: Anucleated cells

text: An anucleated cell contains no nucleus and is, therefore, incapable of dividing to produce daughter cells. The best-known anucleated cell is the mammalian red blood cell, or erythrocyte, which also lacks other organelles such as mitochondria, and serves primarily as a transport vessel to ferry oxygen from the lungs to the body's tissues. Erythrocytes mature through erythropoiesis in the bone marrow, where they lose their nuclei, organelles, and ribosomes. The nucleus is expelled during the process of differentiation from an erythroblast to a reticulocyte, which is the immediate precursor of the mature erythrocyte.[64] The presence of mutagens may induce the release of some immature "micronucleated" erythrocytes into the bloodstream.[65][66] Anucleated cells can also arise from flawed cell division in which one daughter lacks a nucleus and the other has two nuclei.

text: In flowering plants, this condition occurs in sieve tube elements.

text: Multinucleated cells

text: Multinucleated cells contain multiple nuclei. Most acantharean species of protozoa[67] and some fungi in mycorrhizae[68] have naturally multinucleated cells. Other examples include the intestinal parasites in the genus Giardia, which have two nuclei per cell.[69] In humans, skeletal muscle cells, called myocytes and syncytium, become multinucleated during development; the resulting arrangement of nuclei near the periphery of the cells allows maximal intracellular space for myofibrils.[6] Multinucleated and binucleated cells can also be abnormal in humans; for example, cells arising from the fusion of monocytes and macrophages, known as giant multinucleated cells, sometimes accompany inflammation[70] and are also implicated in tumor formation.[71]

text: A number of dinoflagellates are known to have two nuclei.[72] Unlike other multinucleated cells these nuclei contain two distinct lineages of DNA: one from the dinoflagellate and the other from a symbiotic diatom. The mitochondria and the plastids of the diatom somehow remain functional.

text: Evolution

text: As the major defining characteristic of the eukaryotic cell, the nucleus' evolutionary origin has been the subject of much speculation. Four major hypotheses have been proposed to explain the existence of the nucleus, although none have yet earned widespread support.[73]

text: The first model known as the "syntrophic model" proposes that a symbiotic relationship between the archaea and bacteria created the nucleus-containing eukaryotic cell. (Organisms of the Archaea and Bacteria domain have no cell nucleus.[74]) It is hypothesized that the symbiosis originated when ancient archaea, similar to modern methanogenic archaea, invaded and lived within bacteria similar to modern myxobacteria, eventually forming the early nucleus. This theory is analogous to the accepted theory for the origin of eukaryotic mitochondria and chloroplasts, which are thought to have developed from a similar endosymbiotic relationship between proto-eukaryotes and aerobic bacteria.[75] The archaeal origin of the nucleus is supported by observations that archaea and eukarya have similar genes for certain proteins, including histones. Observations that myxobacteria are motile, can form multicellular complexes, and possess kinases and G proteins similar to eukarya, support a bacterial origin for the eukaryotic cell.[76]

text: A second model proposes that proto-eukaryotic cells evolved from bacteria without an endosymbiotic stage. This model is based on the existence of modern planctomycetes bacteria that possess a nuclear structure with primitive pores and other compartmentalized membrane structures.[77] A similar proposal states that a eukaryote-like cell, the chronocyte, evolved first and phagocytosed archaea and bacteria to generate the nucleus and the eukaryotic cell.[78]

text: The most controversial model, known as viral eukaryogenesis, posits that the membrane-bound nucleus, along with other eukaryotic features, originated from the infection of a prokaryote by a virus. The suggestion is based on similarities between eukaryotes and viruses such as linear DNA strands, mRNA capping, and tight binding to proteins (analogizing histones to viral envelopes). One version of the proposal suggests that the nucleus evolved in concert with phagocytosis to form an early cellular "predator".[79] Another variant proposes that eukaryotes originated from early archaea infected by poxviruses, on the basis of observed similarity between the DNA polymerases in modern poxviruses and eukaryotes.[80][81] It has been suggested that the unresolved question of the evolution of sex could be related to the viral eukaryogenesis hypothesis.[82]

text: A more recent proposal, the exomembrane hypothesis, suggests that the nucleus instead originated from a single ancestral cell that evolved a second exterior cell membrane; the interior membrane enclosing the original cell then became the nuclear membrane and evolved increasingly elaborate pore structures for passage of internally synthesized cellular components such as ribosomal subunits.[83]


document_title: Supporting characters on Will & Grace

question_text: who plays the short cop on will and grace

text: Supporting characters on Will & Grace

text: Supporting characters[edit]

text:
Actor
Character
Seasons

1
2
3
4
5
6
7
8
9

Leigh-Allyn Baker
Ellen

Tom Gallop
Rob

Molly Shannon
Val Bassett

Debbie Reynolds
Bobbi Adler

Steve Paymer
Steve

Gregory Hines
Ben Doucette

Marshall Manesh
Mr. Zamir

Laura Kightlinger
Nurse Sheila

Sydney Pollack
George Truman

Tim Bagley
Larry

Jerry Levine
Joe

Sara Rue
Joyce Adler

Lesley Ann Warren
Tina

Woody Harrelson
Nathan

Leslie Jordan
Beverley Leslie

Blythe Danner
Marilyn Truman

Eileen Brennan
Zandra

Charles C. Stevenson Jr.
Smitty

Rip Torn
Lionel Banks

Harry Connick, Jr.
Dr. Marvin 'Leo' Markus

Minnie Driver
Lorraine Finster

Jamie Kaler
Gary

Emily Rutherfurd
Joanne

Jon Fleming
Russell

Bobby Cannavale
Vince D'Angelo

Alec Baldwin
Malcolm Widmark

Mathew Botuchis
Dave

Bernadette Peters
Gin

text: Family members[edit]

text: Grace's family[edit]

text:
Dr. Marvin "Leo" Markus, portrayed by actor and singer Harry Connick, Jr., is a Jewish doctor and Grace's husband from the fifth season. Leo meets Grace Adler in Central Park while she is on her way to be artificially inseminated with gay best friend Will's baby. After Will finds out that Leo and Grace are dating, they have their biggest fight of the entire series, in which Will tells Grace to move out. Thanks to Jack and Karen's meddling, they forgive each other and Will accepts Grace's relationship. In November, 2002, Grace and Leo are married at a spontaneous group ceremony in Central Park, which was supposed to be broadcast on The Today Show. It was later revealed in the storyline that the ceremony was not legal, but the two officially marry at a ceremony soon after. Leo and Grace's relationship was a constant source of tension between Will and Grace, although they eventually achieved a certain accord with each other – Leo even commenting to Will at one point that he considered himself essentially married to both of them due to his ability to accept their close relationship. Leo's true first name is Marvin, as revealed by his mother at their wedding reception. According to The Nation Magazine, this was the first time in television history that a Jewish protagonist character had married inside the faith.[1] Grace immediately realizes she does not know as much about Leo as she expected. Their marriage fails after less than two years, when Leo reveals that he had a one-night stand while working in Cambodia for Doctors Without Borders. Leo admits his affair to Will first. Will then refuses to help Leo break the news to Grace. After Leo comes clean about his affair, Grace briefly considers continuing their marriage, but quickly decides she wants a divorce. Leo reappears during season eight, a little over a year after the divorce in the storyline, in the episode "Love Is in the Airplane." In the episode, he and Grace have a sexual encounter on an airplane after coincidentally ending up on the same flight to London, though Leo was to continue to Thailand. The result is Grace's pregnancy, as discovered in the season eight episode "The Definition of Marriage". A couple of months later Grace meets Leo, with the intention of telling him that she is pregnant with his baby, but he informs her that he is engaged to another woman, Kate. Consequently, Grace decides not to tell Leo about the pregnancy. In the series finale (May 2006) Leo tells a heavily pregnant Grace that he loves her. Leo has a job as a hospital researcher in Rome, Italy, and this is where Grace gives birth. After one year in Rome, Leo and Grace move back to Brooklyn, New York, where they raise their daughter, Laila, together. 11 years later in season 9 it was revealed that this was part of Karen’s dream.
Bobbi Adler, Grace's mother, was played by Debbie Reynolds. Bobbi is an actress and singer, although her performances are generally with the Schenectady Players and involve gender changing roles, in plays such as "Death of a Salesperson", "The Music Person" and "Queen Lear". She has a constant desire to meddle in the love lives of her daughters, is the creator of the Adler family "Told you so" dance, and can always be relied upon to have a song for every occasion. She has, in the past, shown a perfect willingness for Will and Grace to get married. It is mentioned in Season 9 episode "Rosario's Quinceañera" that she died.
Martin Adler, Grace's father, played by Alan Arkin and Robert Klein in Season 9[2]. Portrayed by his family as the stereotypical Jewish patriarch, Martin shows genuine affection for Grace, although remarks he has made suggest Joyce is his favorite. He has been known to pinpoint Grace's flaws without looking up from his Kojak and Baretta reruns.
Janet Adler, Grace's older sister, is played by Geena Davis and Mary McCormack in Season 9. Janet lives in a van and designs jewelry. Her nickname for Grace is "Smudge". It is once implied that she has difficulties with her mother. In the episode "Lows in the Mid-Eighties", Will asks if Grace has another sister named Janet, to which Bobbi, Joyce, and Grace quickly answer "No!"
Joyce Adler, Grace's younger sister, is played by Sara Rue. It is suggested that Grace and Joyce had a not too friendly relationship growing up, and that Joyce was formerly a binge eater. She is often hostile to Grace, but one word from Will and she tends to giggle and act girlishly; it appears that she, like Grace before her, has a crush on Will.
Laila Markus, Grace and Leo's daughter, is played by Maria Thayer. Laila was conceived by Leo and Grace on an aircraft, during a period where her parents were divorced. She was going to be raised by Will and Grace, but her parents remarried shortly before her birth. She appears on screen only during the series finale.
Warren, played by Jesse Fremont Allis, is the imaginary son of Grace and Leo in a dream that Grace has during the last episode of season 8. Grace and Will raise 'their' son together.

tag: ul

text: Will's family[edit]

text:
Vince D'Angelo, played by Bobby Cannavale. An Italian-American police officer, Vince first met Will after giving Karen a ticket for speeding and they started dating after the subsequent hearing. Vince was friends with Joe and Larry and began Will's first long-term relationship in the series' run. Vince broke up with Will, requesting time alone after repeatedly losing his job. He re-encountered Will in season 8 and, during the funeral of Will's father, they acknowledged their mutual feelings, thus rekindling their romance. In the finale, Will and Vince are shown to raise a son, Ben, together. 11 years later in season 9 it was revealed that this was part of Karen’s dream.
Marilyn Truman, Will's mother, is played by Blythe Danner. A typical WASP, Marilyn regularly drinks, collects Lladró statues and treats them as if they were her children, and put up with her husband's regular affairs until their ultimate separation. She is not a fan of musical theater – once claiming that Les Misérables was unrealistic because "poor people don't sing that much" – but was impressed with Mamma Mia!. She does not like the jokes Grace and Karen make about Will's sexuality, saying, "Is that a gay joke? I don't like that."
George Truman, Will's father, is played by Sydney Pollack. While he and Will have a close loving relationship, of which both Jack and Grace are envious, it is eventually revealed that he had trouble dealing with telling others of his son's sexuality, initially telling his friends Will was married to Grace. He dies in season 8, only days after having a fight with Will in which he admitted he would rather that Will was not gay.
Sam Truman, Will's brother, is played by John Slattery in season one and Steven Weber in season 8. He had a falling-out with Will over comments Will made about his wife, but reconciled after he had a one-night stand with Grace. He eventually divorced his wife and gained full custody of their two children.
Paul Truman, Will's brother, is played by Jon Tenney. Paul never really came to terms with his brother's sexuality and often behaved like a childish bully, belittling and insulting Will.
Peggy Truman, Paul's wife and Will's sister-in-law, is played by Helen Slater. She was only shown in one episode and came off as waspish and suspicious of Grace's friendly behavior towards her own husband.
Tina, George's mistress, is played by Lesley Ann Warren. She began a relationship with George while he was still married to Marilyn, but was dismayed to learn that George was then seeing his ex-wife behind her back. Ultimately she and Marilyn come to an understanding, that they will share George between them without him knowing what is going on. This arrangement apparently ended not long before George's death.
Jordy Truman, Sam's son and Will's nephew, is played by Reed Alexander. Flamboyant Jordan incenses Will, since Marilyn is incredibly accepting of him even though she was not at first accepting of Will. His nickname is Jordy. He is perceived to be gay by the other characters, although he is still a child, because of his flamboyant nature, love of show tunes and musicals, along with his general disposition.
Casey Truman, Sam's daughter and Will's niece, is played by Kyla Dang. Casey was adopted by Sam and his ex-wife.
Ben Truman, Will and Vince's son, is played by Ben Newmark. Appearing only during the series finale, Ben was apparently born from a surrogate mother using Will's sperm.[3] Upon going to college, he meets and later marries Grace's daughter, Laila.

text: Karen's family[edit]

text:
Stanley "Stan" Walker, Karen's third husband (little is known about her first two), is a mostly unseen character. He is an obese man, and has worn a toupee since his teens. Stan has two children from a previous marriage to a woman named Kathy. Karen fell in love with him in the 1980s but they didn't marry until 1995. Stan was jailed for tax evasion in season four, and began an affair with a cafeteria worker named Lorraine (played by Minnie Driver), and – after his release in season five – continued the affair, ultimately separating from Karen because of it. He is reported to have died at the end of season five but, at the end of season seven, he reveals to Will that he had faked his own death and is hiding out with the aid of the government. He and Karen reconcile in season 8, but subsequently faced marital difficulties and divorce. Stan's popularity with fast food establishments leads to Pizza Hut taking out a full-page ad in the New York Times to congratulate him on his release from prison; Taco Bell also organize a flyover at his funeral. It is revealed in the series finale that Stan's riches were actually borrowed and that he had no real money of his own.
Mason Walker, Stan's son, is another unseen character. He is known to Karen as "the fat one". During one episode, Karen visits Mason during a swim try-out. She cheers and applauds and has a conversation with him until, at the end, she realizes she has been conversing with the wrong boy and not Mason after all.
Olivia Walker, Stan's daughter, is played by Hallee Hirsh. Although she has had fun times with Karen, such as sticking food to the floor to see how long Mason will spend trying to eat it, she also has problems with her stepmother.
Lois Whitley, Karen's mother, played by Suzanne Pleshette. A con artist who used Karen in her early schemes. They had been estranged for several years when they reconciled in season 4, with the help of Jack.
Virginia "Ginny" Delaney, Karen's sister, played by Bernadette Peters. In 1963, as a child, she was injured in a brutal game of Twister played with Karen.
Barry, Karen's cousin, is played by Dan Futterman. Originally a gay bookish homebody, Karen had Will and Jack bring him out of his shell to become an attractive person whom both Will and Jack fall for.
Sylvia Walker, Karen's mother-in-law, is played by Ellen Albertini Dow. She is a woman that 'strikes fear in her heart-facsimile'. A seemingly kind, but homophobic old woman, Sylvia appears in one episode to accompany Will and Jack to a club. In the beginning neither Will nor Jack wanted to babysit Sylvia, known as "Syl". She had been dumped on them by Karen, who then ditched her. Karen and Syl have a caustic relationship.
Sumner, Karen's nephew, is played by Paul Satterfield. Karen tries to keep him from dating Grace in season 3.

text: Rosario Inez Consuela Yolanda Salazar[edit]

text: Karen Walker's put-upon but faithful maid portrayed by actress Shelley Morrison. In 1985, Rosario met Karen Walker at a club, while working as a cigarette lady, and went to work for her as a maid, which was where she was working when the series began in 1998. Rosario and Karen are very close, but their relationship is love-hate. They are notorious for swapping insults. Rosario is just as feisty as Karen, and is one of the few people who manage to go head-to-head with her. A native of El Salvador, Rosario was a school teacher who received a bachelor's degree in clinical psychology from the University of Texas and who almost got a master's degree. She also attended business school. At some point, she moved to the Bronx, presumably while studying business; however, Karen makes a comment that she bought Rosario from Rosario's parents. While there, she also performed with a then-unknown Jennifer Lopez, including a production of "Tea for Two" at the Shalom Retirement Center. At one point, she was also paid to tape pornographic videos for Tommy Lee. Although she had been mentioned by Karen since the pilot episode, Rosario's first appearance was in the season 1 finale. Due to Karen's patronizing tone, we're made to think that Rosario doesn't speak English well. Rosario actually speaks English fluently, albeit with a thick accent, but is an illegal alien. To keep her in the country, Karen has her marry Jack McFarland, her gay friend, to get a green card. The marriage was later terminated at the end of season 2 when Rosario asked for a divorce in order to pursue other romantic interests. However, she maintained a close relationship with Jack (often echoing hers with Karen) and claimed to still think of him as family. In the series finale, Rosario was shown to have lived with Karen and Jack in the years after the show ended, growing older with them and possibly still working for them despite being in a wheelchair (though she states that she is only in the wheelchair due to a sprained ankle).

text: Jack's family[edit]

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Judith McFarland, Jack's mother, is played by Veronica Cartwright. Despite the obvious clues, Judith did not learn about Jack's sexuality until he was 30. She was impregnated with Jack while at a swinger's costume and pool party.
Daniel McFarland, Jack's stepfather, is played by Beau Bridges. Daniel always had trouble relating to Jack, due to his own athleticism and Jack's lack thereof. Despite Jack's statements to the contrary, Daniel is shown to be a caring man who is at least recently trying to reconnect with Jack.
Joe Black, Jack's biological father. Never portrayed on screen, Joe was revealed to have attended a swingers costumed pool party during the 60s, where he was dressed as Richard Nixon. During the party he impregnated Judith, who was dressed as the rear end of a horse. He dies several years before Jack discovers that Daniel McFarland is not his biological father.
Elliott, Jack's son, is played by Michael Angarano. Shortly after learning of his biological father's death, Jack meets Elliott – his biological son created from sperm Jack donated at the age of 17. He is described by Will as, "Polite, sweet, and kind" which, he says, is the reason Karen initially dislikes him. His relationship with Jack is shown to be very close – Jack noting in one episode that he wants to avoid being the kind of father he had as he always regretted the fact that they never really connected. However, they have a brief rift when Elliott prepares to leave for college during the last season.
Bonnie, Elliott's mother, is played by Rosie O'Donnell. Initially, Bonnie did not want Jack to be included in Elliott's life. Bonnie was a lesbian, but was not open about her sexuality to Elliott. She felt jealous that Jack found it easy to be open with Elliott about his sexuality when she did not feel she could be.

text: Friends[edit]

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Rob and Ellen, Will and Grace's close friends, are played by Tom Gallop and Leigh-Allyn Baker. Ellen and Grace were best friends since college, as were Rob and Will, and the two couples regularly played charades and other games during dinner parties. Grace also sleeps with Rob in season one when they were both going through break-ups and felt emotionally vulnerable, a fact that didn't come up until Rob and Ellen's wedding some years later. The couple did get married, however, and have since had three children, the youngest named Roman (which is the name of Debra Messing's real-life son, born in 2004). Rob and Ellen want to separate, so that they could begin dating other people, and they announce their separation at a dinner date with Will and Grace. Grace makes them realize that they had worked at their marriage and they should remain together; and also keenly reminded them that no one else would have them. Rob and Ellen decided to give their marriage another chance.
Joe and Larry are Will, Jack and Grace's close friends, and are played by Jerry Levine and Tim Bagley. A gay couple, once party animals, Joe and Larry adopted a baby girl called Hannah in season three. Karen occasionally refers to them as "Mo and Mary", with "Mo" being a play on the word "Homo".
Val Bassett, a neighbor of Will and Grace, is played by Molly Shannon. Slightly unstable, and alcoholic, Val originally befriends only Will, until Grace eventually discovers some common interests with her. Both of them still consider her unstable, as does Jack, who found her as an uninvited guest in his bedroom. When Grace accidentally attends an AA meeting, she is seen there by Val, who coerces her to stay. Grace pretends to be an alcoholic for the "free food and therapy".
Beverley Leslie, played by Leslie Jordan, is an effeminate and very short "frenemy" of Karen's. Having a wealthy spouse, as Karen does, Karen and Beverley routinely find themselves traveling in the same society circle of the wealthy and elite. Their relationship is that of friends and enemies. Beverley's wife's name is Crystal and is considerably older than he is. His marriage seems to be held together purely out of his love of Crystal's money. Karen, Will, Grace, and Jack see Beverley as a closeted gay man. He is often seen with a younger attractive man named Benji who appears to be his lover, but Beverley tries to pass him off as a "business associate". When Beverley appears on screen he often catches the other characters by surprise. Sometimes his appearance comes after a character says something that could be comically associated with him. For instance, whilst discussing a dessert, Jack says, "I want something small and fruity, with ladyfingers," and Beverley enters. Beverley and Karen often trade insults, as Karen enjoys ridiculing him for his height. Whenever he appears on screen he can usually be heard saying 'Well, Well, Well' in an effeminate way. Crystal later dies and Beverley inherits the fortune. Some years later Karen's husband Stan loses his fortune, putting Karen's extravagant lifestyle in jeopardy. Beverley presumably spends several more years with Benji after Crystal's death, and then begins seeing a reluctant Jack, who only dated Beverley to support Karen's excessive spending habits, as she had done for him for so many years. During the series finale Beverley is swept off a balcony by a strong gust of wind and dies, leaving his estate in his will to Jack.
Rory, Toby, and Josh are friends of Jack who are never seen, but mentioned in various episodes. Early in Season 3 Rory is mentioned as being into Asian men. In Season 4 Josh, Toby and Jack watch a video of Will freezing up on camera talking about Stanley Walker, but Josh and Toby leave before Will gets home.

text: Love interests[edit]

text: Grace[edit]

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Nathan, played by Woody Harrelson. Nathan is Grace's neighbor in season 3, who becomes her boyfriend. They appear to be a good match, but early in Season 4 he abruptly proposes to her during sex and she becomes distraught at the unromantic nature of his proposal, forcing him to take it back and ask again in a more romantic way. For several days they are awkward around each other and, fearing that their relationship is over, Grace proposes to Nathan who reluctantly refuses and breaks up with her.
Ben Doucette, played by Gregory Hines, is introduced in mid-season 2. Grace sues him after he violates her contract of employment, firing her without reimbursement for expenses she incurred while decorating his house. Although at first he played Grace and Will, who was representing her, he eventually gave her the money voluntarily and hired Will to work at his renowned law firm. Grace and he disliked each other for the rest of the season, until the season finale when Ben showed her his more humane face, when Will invited him to dine with them. They then started a happy, semi-monogamous relationship that lasted for roughly six months, until they broke up early in Season 3 when they realized that they were not in love.
Josh, played by Corey Parker. A sweet, romantic New Age-y man whom Grace dates in season 2. Grace often has issues with him being far too affectionate and nice, to the point of being obnoxious. The two broke up because Jack confessed that he had slept with him.
Nick, played by Edward Burns. A greetings-card writer who falls for Grace when he meets her one Valentine's Day in season 7, after her divorce from Leo. Nick is the first guy Grace starts dating after her divorce with Leo. They decide to break up when he has to go out of the country to work on a screenplay he wrote.
Tom Cassidy, played by Eric Stoltz. An old friend of Grace's, now married, with whom she reunited briefly at the end of season 7. He asks her to help design his and his wife's hotel, yet she still feels chemistry with him and kisses him. She nearly takes it further, but feels guilty and breaks it off with him at the beginning of season 8.
Danny, played by Tom Verica, Grace's long-term boyfriend from roughly 1995–1998, whom she nearly marries in the pilot episode. She realizes, after Will advised her against the marriage, that Danny was too immature for her, and practically leaves him at the altar. They reunite at the end of season 1, much to Will's dismay. Yet again Grace decides that she does not love him and, after roughly a week (one episode), Grace breaks up with him off-screen.
Mark, played by Ken Marino, is another of Grace's partners in Season 3, "Three's a Crowd, Six is a Freakshow". She dumps him because he has 6 toes, although the actual 6th toe was not seen in the episode.

text: Will[edit]

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Barry, played by Dan Futterman. Karen sets up her hopeless cousin Barry with Will, shortly after he comes out. Will and Jack soon undertake a Pygmalion-esque attempt at turning Barry into a more confident gay man, ending when Will falls for Barry though Barry wants to play around before settling down.
James Hanson, played by Taye Diggs. Will meets James at a Manhattan theater and the two have an immediate connection. He later runs into James while on a trip to Los Angeles. James has recently discovered he is going to be deported back to Canada. Grace agreed to marry James so that he can acquire a green card in order to remain in the United States, thus giving James and Will's relationship a chance. However, Will soon discovers James was not who he thought he was, as James began showing himself to be self-centered. Will requests that Grace annul their marriage.
Matthew, played by Patrick Dempsey, is a sports reporter Will meets at a Banana Republic store while trying to help Jack woo him. Jack and Matt have little in common and Will instead finds himself in a relationship with him. They date for a while but Matt's refusal to come out leads to their break-up.
Scott, played by Branden Williams, is Will's 23-year-old date in two episodes in season 3, and works at a local video rental shop. Although they get along well together, Will feels self-conscious about dating Scott, who is quite a bit younger than he is. Will agrees to break it off with Scott if Grace agrees to dump Nathan. Grace agrees and Will breaks up with Scott, though Grace keeps on seeing Nathan.
Diane, played by Mira Sorvino & Lisa Borgnes, is a woman with whom Will has a drunken one-night stand in order to convince himself he was a 100% gay after leaving Grace. She is also one of Leo's exes. Both of these facts make Grace very jealous. Diane states that Will is much better in bed than Leo. Diane was shown briefly (though she had no lines) in the season 3 episode titled "Lows In the Mid-Eighties", but was played by a writer's assistant, Lisa Borgnes.
Claire, played by Megyn Price, is Will's high school friend and girlfriend, the first of the only two women Will has ever dated, the second being Grace. She lives in Paris and asks Will to donate sperm so that she can have a baby, but Will realizes that if he was going to donate sperm he wanted to donate it to Grace.
Michael, played by Chris Potter in season 2 and Cheyenne Jackson in season 9, is a mostly unseen character and is Will's lover of seven years. When the sitcom first appeared, he and Michael had recently broken up. Michael appears in the episode "Hey La, Hey La, My Ex-Boyfriend's Back", which aired on March 14, 2000. He is mentioned occasionally by Will and Grace, and more than once Will refers to him as the love of his life. In the early seasons of the show Will has a hard time letting him go. He and Will begin dating again in season 9, but Will ends ti when Michael asks for money.

text: Karen[edit]

text:
Lyle Finster, played by John Cleese. Lyle is the father of Stan's mistress, Lorraine. He becomes Karen's fourth husband for about 20 minutes until the couple realize how little they had in common outside of the bedroom.
Scott Woolley, played by Jeff Goldblum. Wooley is the man who lost to Karen for Student Body President and has spent his life hatching schemes to ruin her. Sadly, his schemes are often poorly thought out and eventually Grace realises that he doesn't hate Karen, he loves her. However, his attempts to woo her are as misguided as his previous ones. Woolley also has a dreadful sense of word-play (i.e. "The Scotty Mammoth", "Beam me up, Woolley"). He also changes his first name when using an alias, whereas most people change their last names.
Lionel Banks, played by Rip Torn. Banks is a bachelor who falls for Karen, under her alias Anastasia Beaverhausen, while Stan is in jail and tempts her into having an affair.
Malcolm Widmark, played by Alec Baldwin. Widmark is a government agent who helps Stan fake his death. He has a brief relationship with Karen before she reconciles with Stan, and Widmark goes on a government mission to Sri Lanka. Malcolm reappears in the final two episodes of season 9, where it is revealed that he and Karen go on a rendezvous trip every year. However, Malcolm is very tired of having to hide from Stan and pressures Karen into deciding between him and Stan. Though she is reluctant to change their situation and despite both of them being tempted to give in to each other, Karen decides to stay with Stan and she and Malcolm share an awkward goodbye.

text: Jack[edit]

text:
Stuart Lamarack, played by Dave Foley, is a client of Will's who becomes Jack's longest relationship, until Jack cheats on him.
Drew, played by Ryan Pinkston, is a police officer, Vince’s co-worker and Jack’s boyfriend for the second half of season 9. Jack meets him at Vince D’Angelo’s wedding in “The Wedding”. As Drew is the only cop at the wedding whose favourite show is “This is Us”, Jack concludes he must be gay and sleeps with him. This turns out to be the first gay experience for the formerly straight Drew, who reveals he is married, tells Jack he loves him and then introduces him to his wife Angela. Jack is annoyed at that revelation, but later comes to relish it and he and Drew go at it in the bathroom. In the next episode, Jack and Drew start seeing each other secretly and Jack, nervous about screwing things up too soon, advises a reluctant Drew to hold off on coming out to Angela for the time being. He even supports the alibi of them being just guy friends by having Karen pose as his wife. However, Karen, reminded of her mother’s unhappiness in her marriage, outs both Jack and Drew in front of Angela, who is surprisingly supportive and arranges a coming out party for Drew, much to Jack’s distress. Jack admits to Drew that he fears missing out on other great men in his life, but when Karen reminds him of his fear of being old and lonely, which is even worse, he decides to give Drew another chance. In “One Job”, after two months of dating, Drew breaks up with Jack, admitting he is not ready for a serious commitment at the moment and wants to see other people. Jack is devastated at the breakup, as he realises that he is now ready to settle down with someone.
Jack has countless short-term lovers over the course of the series (and presumably long before and after), although most are never mentioned by name, or mentioned at all; it is constantly assumed, and not always stated, that he has multiple boyfriends in every episode. Due to Jack's promiscuity, and his habit of forgetting his boyfriends' names, it would be literally impossible to list all of his love interests over the course of the show. Will jokes that if he was to avoid every man that Jack has ever slept with, "that would leave [him] with women." Grace jokes that if everyone stopped working for every man that broke his heart "the city would shut down." Jack also comments that he goes on thousands of dates a year.

text: Other supporting characters[edit]

text:
Lorraine Finster, played by Minnie Driver, is Stan's mistress. She is a slutty prison cafeteria worker (and, it is implied, prostitute) who instantly forms a hatred of Karen. She was Karen's stepdaughter very briefly (for about 20 minutes) when Lyle, her father, marries Karen. Lorraine was unable to attend the wedding due to an aggressive strain of herpes that kept her from flying. According to the episode "The Accidental Tsuris" she was raised as a girl, despite being genetically male or perhaps a hermaphrodite. It is implied she was estranged from her father for several years and may have been born out of wedlock.
Harlin Polk, played by Gary Grubbs, is a major client of Will's in season one who ultimately fires him.
Mrs. Freeman, played by Jo Marie Payton, is an executive assistant at Doucette & Stein, her most commonly uttered phrase is "Mm-hmm" which is often said with sass.
Zandra Zoggin, played by Eileen Brennan, is Jack's crusty acting coach and a chain-smoking former Hollywood star. After Jack takes over her class, Zandra loses her interest in life and ends up in an actor's retirement village.
Dr. Jay Markus, played by Tom Skerritt, is Leo's father and Grace's eventual father-in-law. She meets him during brunch, thinking he is one of Leo's "old friends".
Eleanor Markus, played by Judith Ivey, is Leo's mother and a noted author of three books on theatre; she meets Grace during brunch alongside her husband. She also is the first to tell her new daughter-in-law her son's actual name, Marvin.
Mr. Stein, played by Gene Wilder, is the senior partner at Will's firm, an eccentric man who takes a liking to Will. He refers to Will as "Gay Will," but without at first realising that Will is actually gay. He and Karen are attracted to each other, but nothing comes of it. He is away from the office for some time prior to season 5 due to a mental breakdown and subsequent incarceration in a mental facility; having been referred to in the company letter-head as running "The London Office" in his absence.
Margot, played by Lily Tomlin, is a senior partner at Will's firm, who apparently takes over after Mr. Stein. She is also quite eccentric and sarcastic. She promotes Will to partner.
Dorleen, played by Parker Posey, is Jack's bitchy, chain-smoking boss during his brief tenure at Barneys New York.
Mr. Zamir, played by Marshall Manesh, is an obnoxious tenant in Will and Grace's building, with a tendency to take off his shirt and to steal Will and Grace's newspapers.
Benji, played by Brian A. Setzer, is Beverley Leslie's "business associate" and boytoy.
Joanne, played by Emily Rutherfurd, is a student of Zandra's acting class who becomes a devoted follower of Jack and his "McFarland method".
Russell, played by Jon Fleming, is a handsome, muscular student of Zandra's acting class who is often asked by Jack to take his shirt off when Jack is teaching the "McFarland method".
Julius, played by Neil Vipond, is Bobbi Adler's close friend and a pianist.
Gary, played by Jamie Kaler, is Will's coworker at Doucette and Stein.
Nurse Sheila, played by Laura Kightlinger, is a rather creepy nurse who works at the sperm bank (where Will visits, intending to donate sperm to his high-school friend Claire). She openly admits she is a whore in season 4 (when Will and Grace are planning to have a baby together), and thereafter seems to appear whenever Will goes into a hospital. She is pregnant in season 8 and attends birth-classes alongside Grace. Her brother, a doctor played by guest-star Jack Black (Kightlinger's real-life former boyfriend), claims he would be "tappin' that big time" if they weren't related.
Dave, played by Mathew Botuchis, is the only openly straight worker at OutTV, the gay network where Jack works in the last seasons. Jack is unimpressed with his heterosexuality and instead refers to him as Elizabeth.
Jamie, played by John Ducey, is the station manager at OutTV.
Tim, played by Mark Harelik, is a member of Senior Management at OutTV.
Jimmy, played by Sam Pancake, is a colleague of Jack's at OutTV.
Smitty, played by Charles C. Stevenson Jr, is a bartender who regularly serves Karen at different establishments. She has been known to call other bartenders "Smitty", even when they tell her it isn't their name. If Karen is depressed Smitty will tell her a tragic story about his own life, which she will laugh at thinking it is a joke.

text: Guest stars playing one-time characters[edit]

text:
Shohreh Aghdashloo, as Pam, an incompetent Iranian hired by Grace who she then fires upon realizing Pam is Jewish and thus she 'doesn't owe (her) anything'.
Rosanna Arquette, as Julie, a masseuse who lives in the same building as Leo and Grace.
Orson Bean, as Professor Joseph Dudley, a gay former literature professor of Will and Grace.
Jason Biggs, as Baby Glenn, a former local celebrity and a guest at Will's auction.
Roscoe Lee Browne, as Linus, owner of a landmark gay bookstore about to be turned into a gym.
Jack Black (uncredited), as Dr. Isaac Hershberg. He examines Karen and is also the brother of the occasionally seen nurse Sheila, played by show writer and Black's girlfriend at the time, Laura Kightlinger.
Richard Chamberlain, as Clyde, an elderly man who Will brings to game night, much to Grace's chagrin
Glenn Close, as Fannie Lieber (a play on celebrity photographer Annie Leibovitz), a noted photographer who takes Will and Grace's picture.
Joan Collins, as Helena Barnes, a designer with whom Grace competes for a job, and a nemesis of Karen's.
Macaulay Culkin, as Jason Towne, a lawyer representing Karen in her divorce from Stan.
Tim Curry, as Marion Finster, Lyle Finster's brother.
Matt Damon, as Owen, Jack's heterosexual rival, pretending to be gay to vie for a spot in the Manhattan Gay Men's Chorus.
Kristin Davis, as Nadine, Vince's straight female friend – the same as Grace is to Will.
Ellen DeGeneres, as Sister Louise, a nun to whom Will sells Grace's uncle's old car.
Michael Douglas, as Gavin Hatch, a somewhat closeted gay police detective who becomes attracted to Will and has issues with seeing food stuck in people's teeth.
Christine Ebersole, as Candy Pruitt, another of Karen's rivals.
Edie Falco, as Deirdre, one of a pair of lesbian real-estate "flippers".
Victor Garber, as Peter Bovington, a former actor now working as a doorman.
Andy García, as Milo, a restaurateur, and lover of Karen's, who fails to phone Karen after their date and is confronted by Grace.
Sara Gilbert, as Cheryl who, like Will, is a Barry Manilow fanatic, a.k.a. "fanilow".
Seth Green, as Randall Finn, a former child star.
Clark Gregg, as Cameron, Jack's wealthy boyfriend who becomes Grace's client.
Neil Patrick Harris, as Bill, the leader of a group of so-called "former" lesbians and gays.
Alex Kapp Horner, as Alice Robinson, one of Grace's former classmates.
Peter Jacobson, as Paul Budnik, an overbearing guy who Will dates but is more fond of his dog.
Kathryn Joosten, as the owner to a cabin Grace finds money in.
Stacy Keach, as Wendell Schacter, a former colleague of Jack's who usurps his acting class.

Piper Laurie, as Sharon Timmers, the best friend of Professor Joseph Dudley.
Michele Lee, as Lucille, one of the lesbians who ended up dancing with both Will & Jack.
Hal Linden, as Alan Mills, an elderly gay man who befriends Will and bestows expensive gifts upon him.
Natasha Lyonne, as Gillian, Grace's intern who decides to turn into the spitting image of Karen.
Madonna, as Liz, Karen's roommate.
Lee Majors, as Burt Wolfe, a friend of Grace's father.
Camryn Manheim, as Psychic Sue.
Jason Marsden, as Kim, a friend of Leo's.
Dylan McDermott, as Tom, a boyfriend of Will's who is very closely attached to his elderly mother.
Michael McDonald, as a Don, a student in a cooking class Will takes and dates his brother.
Julian McMahon, guy in an elevator who Grace flirts with.
Demi Moore, as Sissy, Jack's former babysitter.
Nick Offerman, as a plumber that Karen has sex with on Thanksgiving when Stan asks her to be sexually active while he is still in jail.
Offerman appeared in season 9 as Jackson Boudreaux, a celebrity chef who meets Will and Grace at a cooking class, and begins a sexual relationship with both of them.
Sharon Osbourne, as a bartender in No Sex N' in the City.
Peter Paige, as a gay Immigration and Naturalization Service officer whom Jack tries to convince his marriage with Rosario is real.
Scott Patterson, as Grace's former high school crush in "Das Boob".
Sara Paxton, as Melanie, the head cheerleader at Elliot's school.
Luke Perry, as Aaron, a "hot gay nerd" bird-watcher on whom Jack develops a crush.
Jeremy Piven, as Nicholas, Grace's ex. who asks Grace if she wants to join him in a threesome with his current lover.
Chita Rivera, as Lenore, one of the lesbians who ended up dancing with Will & Jack.
Brandon Routh, as Sebastian, a stud whom Alan Mills replaces Will with, after the two have a falling out over Will's misinterpretation of their relationship.
Chloë Sevigny, as Monet, a wealthy bisexual real-estate agent who falls for Will.
Nicollette Sheridan, as Dr. Danielle Morty, a fellow doctor who wanted Leo sexually.
Jamie-Lynn Sigler, as Ro, Vince's lesbian sister.
Britney Spears, as Amber Louise, a conservative Christian and a "hardcore lesbian" as she describes herself, and a co-host to Jack on his talk show.
Wendie Jo Sperber, as April, Grace's short-lived housekeeper.
Sharon Stone, as Georgia Keller, Will and Grace's therapist.
Larry Sullivan, as Robert, Will's ballet dancing boyfriend on the holiday episode "Jingle Balls".
Wanda Sykes, as Cricket, a woman Karen offers to pay to deliver a child for her.
Tamlyn Tomita, as Naomi, half of the couple that takes Will and Grace out all night.
Rip Torn, as Lionel Banks, a man with whom Karen almost cheats on Stan with during his incarceration.
Stuart Townsend, as Edward, Karen's pansexual pastry chef, who ends up "sexing" Will, Karen, and Rosario.
Tracey Ullman, as Anne, the instructor of a couples cooking class that Will, Jack, and Jack's boyfriend Stuart attend.
Steve Valentine, as Kai, half of the couple that takes Will and Grace out all night.
Steven Weber, as Will's brother Sam.

text: Guest stars playing themselves[edit]

text:
Kevin Bacon
Candice Bergen
Sandra Bernhard
Cher
Katie Couric
John Edward
Jennifer Lopez

Rudy Galindo
Hall & Oates
Deborah Harry
Janet Jackson
Elton John
James Earl Jones

Matt Lauer
Stone Phillips
Josh Lucas
Patti LuPone
Barry Manilow
Martina Navratilova

Bebe Neuwirth
Al Roker
George Takei
Rip Taylor