Abstract

In Drosophila melanogaster, a specificPGAL4 transposon induces theVoila¹ genetic variant and produces multiple phenotypes. HomozygousVoila^1/1 flies rarely reach adulthood, whereas heterozygousVoila^1/+ adult males show strong bisexual behavior. Males with a single copy ofVoila¹ driving the feminizing transgene UAS-transformer show very reduced sexual activity but no overall effect on their behavior.Voila¹ is specifically expressed in the nervous system. In the CNS, it is expressed mainly in the mushroom bodies and, to a lesser extent, in the antennal lobes. In the peripheral nervous system, GAL4 expression is almost entirely restricted to the gustatory sensilla. Using chromosomal deficiencies, the behavioral alteration was genetically mapped to the same location as the PGAL4 element (86E_1–2). The multiple behavioral effects of the Voila genetic variant are discussed in light of its expression in the nervous system and its genetic basis.