CHAPTER 48 – Sodefrin and Related Pheromones

This article describes the current state of understanding of sodefrin, a peptide pheromone from the newt Cynops pyrrhogaster, and [Leu3, Gln8] sodefrin (silefrin) from the congeneric species, C. ensicauda. Both pheromones are composed of 10-amino-acid residues and were isolated from the abdominal glands of the male newts. They exhibit a potent female-attracting activity only to the conspecific females, suggesting a contribution of the pheromones to maintaining the reproductive isolation of the species. Both pheromones are generated from 20 kDa precursor molecules. These pheromones are emitted through the cloaca of the male and are directed toward the female partner's snout during courtship to act primarily on the lateral nasal sinus cells. Hormone dependency of secretion of and response to the pheromones has been demonstrated.