Drosophila brain mRNA sequencing reveals Astray, a glial protein as a regulator of starvation induced sleep suppression during glucose starvation

Abstract

Starvation often causes hyperactivity and suppresses sleep in fruit flies. However, the genes mediating this behavior remain largely unknown in fruit flies as well as other species. To find genes responsible for starvation induced sleep suppression we isolated brain total RNA from flies starved and sleep deprived for 6hrs, 12hrs, 18hrs and 24hrs. mRNA sequencing was utilized and Differential Expressed Gene analysis was conducted to find genes that respond to starvation and sleep deprivation. Among the many genes that changed its transcription level, aay(astray) which is a gene expressed mainly in the brain glia increased its transcription by nearly eight fold after 24hrs of starvation. This induction of aay expression was localized mainly to the subesophageal ganglion and antennal lobe regions of the brain. When aay levels were depleted in hypomorphic flies, they showed resistance to starvation induced sleep suppression. Knocking down aay via RNAi specifically in the glia mimicked aay hypomorph’s starvation resistant phenotype. These findings suggest that not only neural networks, but also the glia cells facilitating the function of neurons are important for starvation induced sleep suppression.