Fruitless is in the regulatory pathway by which ectopic mini-white and transformer induce bisexual courtship in Drosophila

Bisexual courtship in male Drosophila melanogaster may be induced in some c ircumstances. These include ectopic expression of the transformer (tra) gen e, ectopic expression of the mini-white gene, and the homozygous presence o f mutant alleles of fruitless (fru) gene. Experiments were performed to det ermine if ectopic mw and fru. as well as ectopic tra and fru, acted in the same pathway to control courtship. Male flies homozygous for the fru(sat) a llele court females little if at all and males at a low level. When homozyg ous, the fru(sat) allele suppresses the bisexual courtship induced by both ectopic mw and ectopic tra, indicating that the fru wild-type function is n ecessary for expression of the ectopic mw and ectopic tra effect. This demo nstrates that fru shares a pathway controlling courtship behavior with thes e ectopically expressed genes.