Sex- and clock-controlled expression of the <i>neuropeptide F</i> gene in <i>Drosophila</i>

<jats:p> <jats:italic>Drosophila</jats:italic> neuropeptide F (NPF), a homolog of vertebrate neuropeptide Y, functions in feeding and coordination of behavioral changes in larvae and in modulation of alcohol sensitivity in adults, suggesting diverse roles for this peptide. To gain more insight into adult-specific NPF neuronal functions, we studied how <jats:italic>npf</jats:italic> expression is regulated in the adult brain. Here, we report that <jats:italic>npf</jats:italic> expression is regulated in both sex-nonspecific and male-specific manners. Our data show that male-specific <jats:italic>npf</jats:italic> (ms- <jats:italic>npf</jats:italic> ) expression is controlled by the <jats:italic>transformer</jats:italic> ( <jats:italic>tra</jats:italic> )-dependent sex-determination pathway. Furthermore, <jats:italic>fruitless</jats:italic> , one of the major genes functioning downstream of <jats:italic>tra</jats:italic> , is apparently an upstream regulator of ms- <jats:italic>npf</jats:italic> transcription. Males lacking ms- <jats:italic>npf</jats:italic> expression (through <jats:italic> tra <jats:sup>F</jats:sup> </jats:italic> -mediated feminization) or <jats:italic>npf</jats:italic> -ablated male flies display significantly reduced male courtship activity, suggesting that one function of ms- <jats:italic>npf</jats:italic> neurons is to modulate <jats:italic>fruitless</jats:italic> -regulated sexual behavior. Interestingly, one of the ms- <jats:italic>npf</jats:italic> neuronal groups belongs to the previously defined clock-controlling dorsolateral neurons. Such ms- <jats:italic>npf</jats:italic> expression in the dorsolateral neurons is absent in arrhythmic <jats:italic> Clock <jats:sup>Jrk</jats:sup> </jats:italic> and <jats:italic> cycle <jats:sup>02</jats:sup> </jats:italic> mutants, suggesting that <jats:italic>npf</jats:italic> is under dual regulation by circadian and sex-determining factors. Based on these data, we propose that NPF also plays a role in clock-controlled sexual dimorphism in adult <jats:italic>Drosophila</jats:italic> . </jats:p>