It’s official: The basement-rated TV show “Dr. Laura,” starring the controversial radio talk hostess Laura Schlessinger, was canceled on Friday, announced the program’s syndicator, Paramount Television. Regularly blasted by gay rights groups from the time the show was first announced last year, the TV series, which was an outgrowth of her radio chatathon, inspired an advertising boycott by such potentially lucrative sponsors as Proctor & Gamble and United Airlines. At heart were Schelessinger’s comments over the radio that homosexuals are biological mistakes. She attempted some retractions of the statements but was never forgiven by GLAAD and other groups. Despite the fury toward Schlessinger and the sponsor boycotts, Paramount insisted upon moving ahead with the show, which in September debuted on the daytime schedule in some key markets but was soon relegated to the early morning hours. Nationwide, “Dr. Laura” ranked No. 132 in the Nielsen ratings. “I believe it could have earned a substantial audience in time,” Schlessinger, obviously overlooking her numbers, said in a statement, “but the television advertiser boycott precluded that.”