Gonadulins, the fourth type of Insulin-related peptides in Decapods

Abstract

Insulin and related peptides play important roles in the regulation of growth and reproduction. Until recently three different types of insulin-related peptides had been identified from decapod crustaceans. The identification of two novel insulin-related peptides from Sagmariasus verreauxi and Cherax quadricarinatus by Chandler and colleagues (doi: 10.3390/ijms18091832) suggested that there might a fourth type. Publicly available short read archives show that orthologs of these peptides are commonly present in these animals. Most decapods have two genes coding such peptides, but Penaeus species have likely only one and some palaemonids have three. The peptides they encode have been called gonadulins, as they seem consistently expressed by the gonads. Interestingly, expression levels can vary thousand-fold within ovary and testis of Portunus trituberculatus, where gonadulin 1 is expressed by the testis and gonadulin 2 by the ovary.View Full Text