Identification of motor neurons and a mechanosensitive sensory neuron in the defecation circuitry of Drosophila larvae
Wei Zhang,
Zhiqiang Yan,
Bingxue Li,
Lily Yeh Jan,
Yuh Nung Jan
Affiliations
Wei Zhang
Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
Zhiqiang Yan
Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States; State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, China; Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, China
Bingxue Li
State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, China; Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, China
Lily Yeh Jan
Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
Yuh Nung Jan
Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
Defecation allows the body to eliminate waste, an essential step in food processing for animal survival. In contrast to the extensive studies of feeding, its obligate counterpart, defecation, has received much less attention until recently. In this study, we report our characterizations of the defecation behavior of Drosophila larvae and its neural basis. Drosophila larvae display defecation cycles of stereotypic frequency, involving sequential contraction of hindgut and anal sphincter. The defecation behavior requires two groups of motor neurons that innervate hindgut and anal sphincter, respectively, and can excite gut muscles directly. These two groups of motor neurons fire sequentially with the same periodicity as the defecation behavior, as revealed by in vivo Ca2+ imaging. Moreover, we identified a single mechanosensitive sensory neuron that innervates the anal slit and senses the opening of the intestine terminus. This anus sensory neuron relies on the TRP channel NOMPC but not on INACTIVE, NANCHUNG, or PIEZO for mechanotransduction.
