The Effect of Mating and the Male Sex Peptide on Group Behaviour of Post-mated Female Drosophila melanogaster

Abstract

Sleep is a highly conserved state in animals, but its regulation and physiological function is poorly understood. Drosophila melanogaster is an excellent model for studying sleep regulation and has been used to investigate how sex and social interactions can influence wake-sleep profiles. Previously we have shown that copulation has a profound effect on day time activity and quiescence (siesta sleep) of individual post-mated females. Here we have the studied the effect of mating and the transfer of the 36 amino acid sex peptide in the seminal fluid on the behavior of mated female Drosophila populations, where there will be ongoing social interactions. The locomotor activity and sleep patterns of virgin and post-mated female D. melanogaster from three laboratory strains (Oregon-R, CantonS and Dahomey) were recorded in social groups of 20 individuals in a 12-12h light-dark cycle. Virgin female populations from all three fly strains displayed consolidated periods of low activity in between two sharp peaks of activity, corresponding to lights-on and lights-off. Similar light-correlated peaks were recorded for the mated female populations, however, the low afternoon activity and siesta seen in 2 virgin populations was abolished after mating in all three strains. In contrast, night activity appeared unaffected. This post-mating effect was sustained for several days and was dependent on the male SP acting as a pheromone. Evidence from mixed populations of virgin and mated females suggests that the siesta of non-mated females is not easily disturbed by the presence of highly active post-mated females.

Control of Daily Locomotor Activity Patterns in Drosophila suzukii by the Circadian Clock, Light, Temperature and Social Interactions

“…A limited analysis of possible behavioral differences between winter and summer morph flies was included for April semifield and corresponding laboratory mimic conditions based on the rationale that a mixture of summer and winter morph flies may be present at this time of year within the United Kingdom. Moreover, as differences in the Drosophila female reproductive state have been reported to affect locomotor activity (Ferguson et al, 2015; Isaac, 2019), we hypothesized that analogous differences might be observed between reproductively active summer morph flies and winter morph flies that have entered reproductive diapause. As described above (in the Materials and Methods section), reproductive quiescence was, indeed, confirmed for the winter morph flies prior to their use in our behavioral analyses.…”

Phenotypic coupling of sleep and starvation resistance evolves in D. melanogaster

“…All females used in our experiments were kept with males, therefore were likely mated. Sex peptides transferred from males dramatically alter female sleep behavior, and these sex-specific differences in temperature response may be caused by evolution in sex peptide genes [ 46 , 47 ]. Along with sex peptides, changes in splicing of circadian clock genes can regulate responses to seasonal changes in temperature and photoperiod [ 44 ], and temperature-induced changes in day sleep are regulated by clock genes [ 45 ].…”

Scared of the dark? Phototaxis as behavioural immunity in a host–parasite system

“…Marginally reduced photophobia among mated females relative to unmated females, independent of mite exposure, may represent increased exploratory behaviour while searching for ovipositing sites [32]. Furthermore, copulation per se can alter the behaviour of female flies [39,40]. For example, copulation increases Drosophila dispersiveness [39].…”