Normal fruitless function is required for proper development of several anatomical structures necessary for courtship, including motor neurons which innervate muscles needed for fly sexual behaviors.
[1] The gene does not have an obvious mammalian homolog, but appears to function in sex determination in species as distant as the mosquito Anopheles gambiae.
Research on fruitless has received attention in the popular press, since it provokes discussion on genetics of human sexual orientation,[3][4] and behaviors such as gender-specific aggression.
[7][8] fruitless has at least four promoters, each encoding proteins containing both a BTB (Broad complex/tramtrack/bric-a-brac) domain and a zinc finger motif.
Early work refers to the gene as fruity, an apparent pun on both the common name of D. melanogaster, the fruit fly, as well as a slang word for homosexual.