Date: September 14, 2017. 12:00
Location: CCU Seminar Room
Affiliation: Tohoku Neuroscience Global COE Basic & Translational Research Center for Global Brain Science, Japan.
The circuit mechanism for courtship behavior in Drosophila melangoaster and beyond.
Approximately 25 years ago, we isolated a Drosophila mutant that we named satori, males of which preferentially courted males rather than females without copulating (Yamamoto et al., 1991, J. Neurogenet. 7, 152). Later, a genetic complementation test revealed that satori was allelic to fruitless (fru). Molecular cloning of the fru gene (Ito et al., 1996, PNAS 93, 9687-9692; Ryner et al., 1996, Cell 87, 1079-1089) and neuroanatomical demonstration of sexual dimorphisms in fru-expressing neurons (Kimura et al., 2005, Nature 438, 229-233) led to the proposition that the fru gene functions as a master regulator of the formation of courtship neural pathways, which operate as hard-wired circuitries to generate genetically determined courtship behavior (Dickson, 2008, Science 322, 904-909). Thus genetic mutations in fru result in changes in the courtship target choice in these males. Recent studies (Kohatsu & Yamamoto, 2015, Nature Commun. 6, 6457; Pan & Baker, 2014, Cell 156, 236-248) have challenged this view, by showing that inappropriate courtship is suppressed in fru mutants that are raised in isolation. I will talk our attempts to determine the mechanism by which social experience affects the mate preference in fru mutants, aiming to unravel the molecular underpinning of gene-environment interactions in shaping the behavior. I will also present our approach to explore the courtship circuitry in a non-model species for understanding the evolutionary basis for behavioral diversification.