2010 | Press Release
The mechanism was disclosed as to how a muscle unique to males forms under the neural instruction - Neuronal Synaptic Outputs Determine the Sexual Fate of Postsynaptic Targets -
Drs. D. Yamamoto, T. Nojima, and M. Koganezawa, at Graduate School of Life Sciences, Tohoku University and Dr. K.-i. Kimura at okkaido University of Education have identified a single motoneuron that induces the muscle of Lawrence (MOL), a male-specific muscle in the vinegar fly Drosophila. The research group has further unraveled the cellular mechanism for the male-specific MOL formation.
The MOL is induced only in the 5th abdominal segment (A5) of adult male Drosophila. For the formation of MOL, it has been shown that the motor nerve innervating the muscle must be composed of male tissue, and Fruitless protein is essential for the nerve to acquire male characteristics.
The research group has succeeded in identifying a sole motoneuron named “Mind” with the ability to induce MOL by using a genetic-mosaic technique, which allows a few neurons to express a functional fruitless+ gene in mutant males that otherwise lack fruitless functions and thus without MOL. The group has specified which neurons express fruitless+ when MOL is restored. The Mind motoneuron is present only in male A5 because its sibs are eliminated by programmed cell death, and the survivor Mind motoneuron likely releases a yet uncharacterized chemical factor to induce MOL. The achievement has explained why MOL is formed only in A5 of males.
The research results have been published online in Current Biology on April 15, 2010. The paper’s title is “Neuronal synaptic outputs determine the sexual fate of postsynaptic targets.”
Professor Daisuke Yamamoto
Graduate School of Life Sciences, Tohoku University
E-mail: daichan*mail.tains.tohoku.ac.jp (Replace * with @)
Associate Professor Fuji Nagami
Tohoku Neuroscience Global COE
Tel: +81-22-717-7908, Fax: +81-22-717-7923
E-mail: f-nagami*mail.tains.tohoku.ac.jp (Replace * with @)