Sexually dimorphic mechanosensory neurons regulate copulation duration and persistence in male Drosophila

Peripheral sensory neurons are the gateway to the environment across species. In Drosophila , olfactory and gustatory senses are required to initiate courtship, as well as for the escalation of courtship patterns that lead to copulation. To be successful, copulation must last long enough to ensure the transfer of sperm and seminal fluid that ultimately leads to fertilization. The fly genitalia contain sex-specific bristle hairs innervated by mechanosensory neurons. To date, the role of the sensory information collected by these peripheral neurons in male copulatory behavior is unknown. Here, we employed genetic manipulations that allow driving gene expression in the male genitalia as a tool to uncover the role of these genitalia specific neurons in copulation. We found that the sensory information received by the mechanosensory neurons (MSNs) at the male genitalia plays a key role in copulation duration. We confirmed that these MSNs are cholinergic and co-express both fru and dsx . Moreover, our results show that the function of these fru/dsx cholinergic MSNs is required for copulation persistence, which ensures copulation is undisrupted in the presence of environmental stress before sperm transfer is complete.