Integration of male mating and feeding behaviors in Caenorhabditis elegans.

The Caenorhabditis elegans male must integrate various environmental cues to ensure proper execution of mating. One step of male mating, the insertion of the male copulatory spicules into its mate, requires UNC-103 ERG (ether-a-go-go-related gene)-like K+ channels. unc-103(lf) alleles cause males to protract their spicules spontaneously in the absence of mating cues. To identify proteins that work with UNC-103, we suppressed unc-103(lf) and isolated lev-11(rg1). LEV-11 (tropomyosin) regulates the spicules directly by controlling the male sex muscles and indirectly by controlling the pharyngeal muscles. lev-11-mediated suppression requires the pharyngeal NSM neurosecretory motor neurons; ablating these neurons in lev-11(rg1); unc-103(lf) males restores spontaneous spicule protraction. Additionally, unc-103-induced spicule protraction can be suppressed by reducing a pharyngeal-specific troponin T. These observations demonstrate that non-genitalia cells involved in feeding also mediate male sexual behaviors.