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Main Menu - Block
- Overview
- Anatomy and Histology
- Cryo-Electron Microscopy
- Electron Microscopy
- Flow Cytometry
- Gene Targeting and Transgenics
- Immortalized Cell Line Culture
- Integrative Imaging
- Invertebrate Shared Resource
- Janelia Experimental Technology
- Mass Spectrometry
- Media Prep
- Molecular Genomics
- Primary & iPS Cell Culture
- Project Pipeline Support
- Project Technical Resources
- Quantitative Genomics
- Scientific Computing Software
- Scientific Computing Systems
- Viral Tools
- Vivarium

Abstract
Genetically hard-wired neural mechanisms must enforce behavioral reproductive isolation because interspecies courtship is rare even in sexually na{\"ıve animals of most species. We find that the chemoreceptor Gr32a inhibits male D. melanogaster from courting diverse fruit fly species. Gr32a recognizes nonvolatile aversive cues present on these reproductively dead-end targets, and activity of Gr32a neurons is necessary and sufficient to inhibit interspecies courtship. Male-specific Fruitless (Fru(M)), a master regulator of courtship, also inhibits interspecies courtship. Gr32a and Fru(M) are not coexpressed, but Fru(M) neurons contact Gr32a neurons, suggesting that these genes influence a shared neural circuit that inhibits interspecies courtship. Gr32a and Fru(M) also suppress within-species intermale courtship, but we show that distinct mechanisms preclude sexual displays toward conspecific males and other species. Although this chemosensory pathway does not inhibit interspecies mating in D. melanogaster females, similar mechanisms appear to inhibit this behavior in many other male drosophilids.