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

Abstract

BackgroundDrosophila 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.ResultsBy 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, including many annotated with neuronal functions. By determining the binding sites of individual FruM isoforms using SELEX we demonstrate that the distinct zinc finger domain of each FruM isoforms confers different DNA binding specificities. A genome-wide search for these binding site sequences finds that the gene sets identified as induced by over-expression of FruM isoforms in males are enriched for genes that contain the binding sites. An analysis of the chromosomal distribution of genes downstream of FruM shows that those that are induced and repressed in males are highly enriched and depleted on the X chromosome, respectively.ConclusionsThis study elucidates the different regulatory and DNA binding activities of three FruM isoforms on a genome-wide scale and identifies genes regulated by these isoforms. These results add to our understanding of sex chromosome biology and further support the hypothesis that in some cell-types genes with male-biased expression are enriched on the X chromosome.

α1‐Adrenoceptor activation of PKC‐ε causes heterologous desensitization of thromboxane receptors in the aorta of spontaneously hypertensive rats

“…second messenger requirements (Webb et al, 2000). Different expressions of PKC isoforms between SHR and WKY smooth muscle may explain TP receptor desensitization caused by α1-adrenoceptor activation in the former (Magnusson et al, 1998;Castellano and Santos, 2011;Dalton et al, 2013). The PKC expression was comparable in aortae of 5-week-old WKY and pre-hypertensive SHR (Sankhanava Kundu, 2008), in line with the observation that previous activation of α1-adrenoceptors did not cause desensitization at that young age in the latter.…”

Fruitless Represses robo1 Transcription to Shape Male-Specific Neural Morphology and Behavior in Drosophila

“…Recently, Dalton et al [25] reported that three sequences, A G T A A C, C C C T T T, and G T T A C A T, were the binding motifs for Fru A , Fru E , and Fru B proteins, respectively, based on the in vitro screens of oligo-DNAs with random sequences for binding to Fru zinc finger motifs fused to glutathione S-transferase (GST). These three reported sequences have little similarity to the Fru BM -binding motif we identified in this paper.…”

Sex-specific regulation of Lgr3 in Drosophila neurons

“…3E). Potential Fru binding sites have been explored previously (15,16 Anticipating that binding at multiple sites may be necessary for Fru function, we mutated our identified sites individually and in multiple combinations in the R19B09.3A reporter (Fig. S5 E and F).…”

“…Fru M appears to function in a complex with the transcription cofactor Bonus and either histone deacetylase 1 or heterochromatin protein 1a (14). Recent genome-wide screens of RNA expression levels or Fru M binding activity have identified potential Fru M targets, but have lacked independent confirmation of such regulation (15)(16)(17). Thus, our understanding of how Fru M specifies the potential for sex-specific behavior remains limited.…”