US comedian Ellen DeGeneres is to receive America's top comedy prize later this month. The award-winning chat show host will be presented with the Mark Twain Prize for American Humor, at the John F Kennedy Center for Performing Arts. Jimmy Kimmel, Kristin Chenoweth and Jason Mraz are among those who will perform tributes to the star. Past winners of the accolade include Whoopi Goldberg, Billy Crystal and Will Ferrell who was last year's recipient. DeGeneres made history on her sitcom Ellen in 1997, when she became the first lead character on a prime-time US TV show to reveal she was gay. Her chat show, The Ellen DeGeneres Show, has won 38 Emmy awards over its 10 seasons and she has appeared on the Forbes list of the 100 Most Powerful Women. A former host of the Academy Awards and Primetime Emmys, she has also featured in several films including Ron Howard's EDtv and The Love Letter starring Bill Pullman. She also provided the voice of Dory in the animated film Finding Nemo in 2003. DeGeneres replaced Paula Abdul as a judge on American Idol in February 2010 but left the show after one season, saying the series "didn't feel like the right fit for me". The Twain prize was first awarded to Richard Pryor in 1998, and "recognizes people who have had an impact on American society in ways similar to the distinguished 19th century novelist and essayist best known as Mark Twain". This year's ceremony will be broadcast in the US on PBS on 22 October, 2012. (bbc)