Investigation of novel functions of three genes in oriental river prawn, Macrobrachium nipponense: Molecular Cloning, Expression, and In situ Hybridization Analysis

Three genes were predicted to be potentially involved in the male sexual development in M. nipponense, including the Gem-associated protein 2-like isoform X1 (GEM), Ferritin peptide, and DNA polymerase zeta catalytic subunit (Rev3). In this study, we aimed to investigate their novel functions in depth. The full-length cDNA sequence of Mn-GEM was 1,018 bp, encoding 258 amino acids. The partial Mn-Rev3 cDNA sequence was 6,832 bp, encoding 1,203 amino acids. Tissue distribution indicated that all of these three genes have higher expression level in testis and androgenic gland, implying their novel functions in male sexual development. In situ hybridization analysis further confirmed the novel roles of these three genes. Rev3 promote the testis development during the whole reproductive cycle, while GEM and ferritin only promote the activation of testis development. Besides, these three genes play essential roles in funicular structure development surrounding the androgenic gland cells, which promote and support the formation of androgenic gland cells. The expression in hepatopancreas cells also suggested their role in immune system in M. nipponense. This study advances our understanding of male sexual development in M. nipponense, as well as providing the basis for further studies of male sexual differentiation and development in crustaceans.