アクティブボード・２０１３年１０月
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研究発表を行った学会；
・Cold Spring Harbor Laboratory Meeting Neurobiology of Drosophila
　２０１３年１０月　１日〜　５日（New York, USA）

タイトル；Male-male interaction-induced sleep in a fruit fly, Drosophila melanogaster.
発表者；冨田　淳　氏
　　　（熊本大学　発生医学研究所　多能性幹細胞分野）
Abstract；
Intraspecific social interaction modulates behavior of exposed animals. The fruit fly Drosophila melanogaster normally exists in groups, and social-experience dependent change in behaviors such as courtship, aggression, circadian locomotion and sleep has been studied. When the individual locomotor activities of flies exposed to either social enrichment or isolation are measured, socially enriched individuals sleep significantly more during daytime than socially deprived siblings.
In this study, we assessed sleep in the flies during the simple social interaction. Single or two male flies were placed in glass tubes (length, 65 mm; inside diameter, 2 mm) containing food at one end and entrained to 12 h light/dark cycle. Their sleep was monitored in constant darkness using the Drosophila activity monitoring system. Control strain showed no significant difference in sleep amount between single and two fly conditions. Interestingly, short sleeper mutant, fumin (fmn) flies with mutated dopamine transporter gene, showed about 2-fold increase in sleep in two male condition compared with single male condition. The male-male interaction-induced sleep in fmn mutants was predominantly observed during early subjective night and required olfactory input. We found that male-male interaction-induced sleep increase was not observed in fmn flies grown on a minimal medium containing only sucrose. Moreover, we identified Odorant receptor 42a (Or42a) as significantly up-regulated gene in the heads of fmn flies by microarray analysis. Or42a is a generalist odorant receptor which is sensitive to a large number of fruit odors. Male-male interaction in Or42a-,fmn double-mutants did not increase sleep. These results suggest that food-derived odors received by Or42a were required for the increase in sleep in interacting fmn males.