A casting call ensued, and Patricia Apollonia Kotero was chosen for the role. Prince liked her middle name, and just like that Apollonia was the new lead singer of Apollonia 6 (still named after the number of breasts in the band ... really). Additionally, Apollonia became the female lead in Purple Rain.
While Apollonia was quite beautiful, she did not have the strongest singing voice, and Prince seemed to lose interest in her (and the concept of a girl band) soon after Purple Rain. There may or may not have been a romantic falling out, as well. As a result, only one album was released, the eponymous 1984 LP. "Sex Shooter" became a minor hit, reaching #85 on the charts, but Apollonia is probably best-known for the movie, and her duet with Prince, "Take Me With You," a top 40 hit from 1985 (and the last single from Purple Rain.)
Apollonia also had a falling out with Prince, and went out on her own in 1985, primarily as an actress. She later went to film school, and I believe that she still runs her entertainment company, Kotero Entertainment.
In addition to the primary video for "Sex Shooter," we also found the performance clip from Purple Rain; in the interests of completeness both are below.
Cool trivia facts: "Take Me With You" was originally intended to be an Apollonia 6 song, but was a late addition to Purple Rain. In additional, "Manic Monday" (later a big hit for The Bangles) and "Glamorous Life" (later a hit for Sheila E.) we both originally written as Apollonia 6 songs.