(written from a Production point of view)
Paul Dooley (born 22 February 1928; age 87) is the Emmy Award-nominated actor who played Enabran Tain in four episodes of Star Trek: Deep Space Nine. He was born in Parkersburg, West Virginia, and began acting while attending college.
Early film and television career
During the early 1960s, he was part of a stand-up comedy act consisting of himself and Richard Libertini known as "Paul Dooley and Dick Liberti". Although the act split up after a short time, Dooley and Libertini later worked on several films together, and Libertini himself also become a guest star on Deep Space Nine.
Having found success on the New York stage, Dooley moved into television in the 1960s, making appearances on such popular shows as The Defenders, Get Smart, and Bewitched. By 1970, he began breaking into feature films as well, with small roles in 1970's The Out-of-Towners (in which he and Richard Libertini played baggage handlers, with Graham Jarvis playing a mugger), 1974's Death Wish, and 1977's Slap Shot.
Perhaps Dooley's most notable stage work was the original Broadway production of Neil Simon's The Odd Couple, in which he portrayed "Speed," one of Oscar Madison's poker buddies. He worked opposite another Star Trek alumnus, John Fiedler, who played the role of Vinnie.  Garry Walberg, who appeared on Star Trek: The Original Series, took over the role of "Speed" for the 1970s television series which followed.
From 1969 through 1970, Dooley performed alongside Graham Jarvis in Elaine May's Adaptation at the Greenwich Mews Theatre in New York.  In 1970, Dooley and Richard Libertini were paired together once again in the off-Broadway production of The White House Murder Case. 
Dooley continued performing on the New York stage throughout the 1970s and 1980s, and in 1986, he worked alongside Gerrit Graham in the play Sills & Company.  Dooley has since performed in the Los Angeles theater, including Morning's at Seven in 2002, for which he replaced Star Trek III: The Search for Spock actor Christopher Lloyd.  Dooley also starred opposite James Avery and Norman Lloyd in a one-night-only performance of Tall Tales at the Colony Theatre. 
Robert Altman films
In 1978, Dooley landed his first major film role in Robert Altman's 1978 comedy A Wedding. This proved to be the first of many collaborations between Dooley and director Altman, making Dooley a part of the unofficial Altman acting troupe which also included the likes of Rene Auberjonois, Henry Gibson, Sally Kellerman, John Schuck, Ray Walston, Robert Fortier, and Bert Remsen (the latter two having also appeared in A Wedding).
The films for which Dooley re-teamed with Altman were 1979's A Perfect Couple (with Gibson), 1980's HealtH (co-written by Dooley and also featuring Gibson, as well as Fortier and Alfre Woodard) and Popeye (in which Dooley plays the hamburger-loving Wimpy, co-starring with Fortier, Richard Libertini, and Ray Walston), 1987's O.C. and Stiggs (with Fortier and Walston), and 1992's The Player, in which Dooley appeared as himself. The latter film also featured appearances by fellow Star Trek performers Rene Auberjonois, Brian Brophy, Louise Fletcher, Teri Garr, Whoopi Goldberg, Joel Grey, Sally Kellerman, Malcolm McDowell, Bert Remsen, Dean Stockwell, Brian Tochi, and Ray Walston.
Breaking Away and Dennis Christopher
It was Dooley's role in Peter Yates' 1979 teen drama Breaking Away, starring fellow DS9 guest actor Dennis Christopher, which acquired him the most recognition. Dooley's performance as the father of Christopher's character earned him an award as Best Supporting Actor from the National Board of Review. This film actually marked the second time Dooley played the father of Dennis Christopher's character; the first was in the aforementioned A Wedding. He played his father again in a 2003 episode of Law & Order: Criminal Intent.
In addition to the above works, Dooley reteamed with Richard Libertini on the 1980s films Going Berserk (also featuring Rosalind Chao and Kurtwood Smith) and Big Trouble (co-starring Warren Munson and Barbara Tarbuck). Dooley also had supporting roles in the 1983 McKenzie Brothers comedy Strange Brew and the 1984 John Hughes comedy Sixteen Candles; in the latter, he played the father of Molly Ringwald's character, Samantha. Dooley subsequently appeared with fellow DS9 guest star Henry Gibson in the 1986 horror comedy Monster in the Closet. He was originally cast as Patrick Martin in Little Shop of Horrors; however, the original ending did not go well with the audience and it was reshot. Dooley was unavailable for the reshoot so Jim Belushi was cast in the role (Dooley is still mentioned under "special thanks" in the end credits).
Dooley's later film credits include the 1993 comedy My Boyfriend's Back, the 1995 science fiction thriller Evolver (working with Q actor John de Lancie), the 1999 comedies Happy, Texas (with Ron Perlman and Scarlett Pomers) and Runaway Bride, and the 2002 Christopher Nolan thriller Insomnia (starring Robin Williams). In addition, Dooley appeared in the Christopher Guest "mockumentaries" Waiting for Guffman (1996) and A Mighty Wind (2003), the latter of which also featured Ed Begley, Jr., Bill Cobbs, and Michael McKean. Dooley again worked with Begley and McKean on Guest's 2006 film For Your Consideration.
Dooley was also the voice of Sarge in the 2006 Disney/Pixar movie Cars. He then played Mr. Spritzer in the acclaimed 2007 film version of Hairspray. He has since been seen in such films as the 2008 comedy Sunshine Cleaning and the 2009 horror-thriller Horsemen, both featuring Clifton Collins, Jr. from 2009's Star Trek.
Later television work
Besides his role as Tain on DS9, Dooley also had recurring roles on a number of other series, ranging from comic shows such as ALF, Grace Under Fire, and Curb Your Enthusiasm to dramas such as ER and Once and Again (with William O. Campbell). One such recurring role, as Martin Tupper's father on the HBO series Dream On, led to his first Emmy Award nomination in 1994. A second nomination followed in 2000 for his recurring role as Judge Philip Swackheim on The Practice. His most recent recurring character is that of Addison Prudy on Desperate Housewives, starring Teri Hatcher, Mark Moses, and his HealtH co-star Alfre Woodard. Dooley also appeared in the 1992 TV movie Perry Mason: The Case of the Heartbroken Bride, in which he played the assistant of Charles Macauley. This telefilm also featured Ronny Cox.
Recurring roles aside, Dooley has made one-time appearances on shows such as Spenser: For Hire (starring future DS9 star Avery Brooks), The Golden Girls, Tales from the Darkside (in an episode with John Fiedler), Coach (as Luther Van Dam's brother), The Wonder Years (starring Olivia d'Abo), Batman: The Animated Series (in an episode with Eugene Roche), Mad About You (as the father of Anne Ramsay's character), Millennium (with Megan Gallagher and Bill Smitrovich), Ally McBeal (with Anne Haney, Albert Hall, and Richard McGonagle), CSI (in an episode with Debra Wilson), and Boston Legal (starring William Shatner and John Larroquette, in an episode with Mark Moses, Michael Wiseman, and Tom Virtue). Additionally, he was seen in the 1995 made-for-TV sci-fi/comedy Out There, along with Leslie Bevis, Bill Cobbs, Wendy Schaal, Carel Struycken, and Star Trek: Voyager star Robert Picardo.