Molecular evolution of the neurohypophysial hormone precursors in mammals: Comparative genomics reveals novel mammalian oxytocin and vasopressin analogues

► Mammalian neurohypophysial hormone precursors were surveyed using genomic data. ► Leu3 oxytocin (OT) found in armadillo and Thr4 arginine vasopressin (AVP) in tenrec. ► These two species also have additional heavily substituted AVP genes/pseudogenes. ► OT and VP gene sequences show evolutionary conservation and often gene conversion. ► Arrangement of monotreme neurohypophysial hormone genes resembles that in eutherians.