Identification and characterization of a crustacean female sex hormone in the giant freshwater prawn, Macrobrachium rosenbergii

Abstract

© 2019 Elsevier B.V. The giant freshwater prawn, Macrobrachium rosenbergii, is an important aquaculture species in many Asian-Pacific countries due to its high economic value. A better understanding of hormones that regulate reproductive processes, including development and maturation of gametes, will facilitate more efficient breeding and larval production in prawn aquaculture. In this study, we identified four gene transcripts from the M. rosenbergii that encode crustacean female sex hormones (CFSHs), which were designated as MroCFSH1a, MroCFSH1b, MroCFSH2a and MroCFSH2b, based on primary sequence and phylogeny. We also show that CFSH may have evolved from an ancestral protein similar to the interleukin 17. All MroCFSH genes are present in the central nervous system (CNS) as well as in other tissues, including the ovaries and testes. The expression level of all MroCFSH during ovarian development is significantly higher in the CNS compared to the ovary. In the brain, MroCFSH expression is localized to small-sized neurons of neuronal clusters 9, 10, and 11, and in the medium- and large-sized neurons of neuronal clusters 14 and 15; regions known to regulate feeding and reproductive behaviors. In the ovary, MroCFSHs expression are found in the oogonia, previtellogenic and early vitellogenic oocytes. A role for CFSHs in M. rosenbergii reproduction was supported following experimental administration of serotonin to ovarian explant cultures, showing an upregulation of MroCFSHs.