and mechanosensors are involved in mating behavior in .

Male mating in is a complex behavior with a strong mechanosensory component. has several characterized mechanotransducer proteins, but few have been shown to contribute to mating. Here, we investigated the roles of , a piezo channel, and , a mechanotransducing TRPN channel, in male mating behavior. We show that is expressed in several male-specific neurons with known roles in mating. We show that, among other neurons, is expressed in the Post-Cloacal sensilla neuron type A (PCA) sensory neuron, which monitors relative sliding between the male and the hermaphrodite and inhibits neurons involved in vulva detection. Mutations in both genes compromise many steps of mating, including initial response to the hermaphrodite, scanning, turning, and vulva detection. We performed pan-neuronal imaging during mating between freely moving mutant males and hermaphrodites. Both and mutants showed spurious activation of the sensory neurons involved in vulva detection. In mutants, this spurious activation might be caused by PCA failure to inhibit vulva-detecting neurons during scanning. Indeed, we show that without functional , PCA fails to detect the relative sliding between the male and hermaphrodite. Cell-specific expression restores PCA's mechanosensory function. Our results demonstrate new roles for both and mechanotransducers in mating behavior.