Neural and non-neural contributions to sexual dimorphism of mid-day

20 21 22. CC-BY-NC-ND 4.0 International license peer-reviewed) is the author/funder. It is made available under a The copyright holder for this preprint (which was not. Abstract 23 24 Many of the characteristics associated with mammalian sleep are also observed in Drosophila, 25 making the fruit-fly a powerful model organism for studying the genetics of this important process. 26 Among these similarities is the presence of sexual dimorphic sleep patterns, which in flies, is 27 manifested as increased midday sleep ('siesta') in males, compared to females. Here, we have used 28 targeted miss-expression of the gene transformer (tra) and tra2 to either feminise or masculinise 29 specific neural and non-neural tissues in the fly. Feminization of males using three different GAL4 30 drivers which are expressed in the mushroom bodies induced a female-like reduced siesta, while the 31 masculinisation of females using these drivers triggered the male-like increased siesta. We also 32 observed a similar reversal of sex-specific sleep by miss-expressing tra in the fat body, a key tissue 33 in energy metabolism and hormone secretion. In addition, the daily expression levels of takeout, an 34 important circadian clock output gene, were sexually dimorphic. Taken together, our experiments 35 suggest that sleep-sexual dimorphism in Drosophila is driven by multiple neural and non-neural 36 circuits, within and outside the brain. 37 38 39 40 41