Male-specific Fruitless isoforms have different regulatory roles conferred by distinct zinc finger DNA binding domains

Drosophila melanogaster adult males perform an elaborate courtship ritual to entice females to mate. fruitless (fru), a gene that is one of the key regulators of male courtship behavior, encodes multiple male-specific isoforms (FruM). These isoforms vary in their carboxy-terminal zinc finger domains, which are predicted to facilitate DNA binding. By over-expressing individual FruM isoforms in fru-expressing neurons in either males or females and assaying the global transcriptional response by RNA-sequencing, we show that three FruM isoforms have different regulatory activities that depend on the sex of the fly. We identified several sets of genes regulated downstream of FruM isoforms. RNA seqeuncing was performed on mRNA derived from adult male or female heads, for a total of 39 samples. These samples included two wild type genotypes (Berlin and Canton-S), two transheterozygous mutants for fru P1 (Df(3R)P14/Df(3R)fru4-40 and fruw12/ Df(3R)ChaM5), and 3 overexpressing genotypes (fru P1-Gal4: UAS-FruMA, UAS-FruMB, UAS-FruMC). There were at least 3 replicates from biological samples for all sex by genotype combinations.