Evolution of the invertebrate Oxytocin/Vasopressin superfamily peptides

摘要

Members of oxytocin/vasopressin(OT/VP)superfamily widely distribute in invertebrates as well as vertebrates,and play key roles as signaling molecules in the regulation of reproduction and osmoregulation.All vertebrate species except for cyclostomes contain at least one OT-family peptide and one VP-family peptide.It has been proposed that vertebrate OT and VP genes have evolved via duplication from a common ancestral gene.In contrast,only a single OT/VP superfamily peptide was isolated from proterostomes.Consequently,the OT/VP family gene might have been present in the Archaemetazoa,a stem group from which both vertebrates and invertebrates diverged about 600 million years ago.However,we have revealed that the common octopus,Octopus vulgaris,has two members of OT/VP superfamily octopressin(OP)and cephalotocin(CT),as in vertebrates,an observation made for the first time in invertebrate.In this report,we analyzed OP and CT mRNAs expression in the Octopus brain,and intron-exon structure and the 5'-flanking regions in OP and CT genes.