iTRAQ-based quantitative proteomic analysis of the androgenic glands of the oriental river prawn, Macrobrachium nipponense, during nonreproductive and reproductive seasons

The androgenic gland produces hormones that play crucial roles in driving male sexual development. In this study, we investigated the regulatory proteins and pathways affecting male sexual development of M. nipponense, by analyzing the proteomes of their androgenic glands during their reproductive and nonreproductive seasons using isobaric tags for relative and absolute quantitation (iTRAQ). A total of 13 sex-related protein homologs out of 999 total proteins were identified in the proteome of M. nipponense based on comparisons with the published literature. A total of 32 proteins were differentially expressed in the androgenic gland between the reproductive and nonreproductive seasons of M. nipponense. However, only 10 differentially expressed proteins (DEPs) were annotated in the Nr, COG, GO, and KEGG databases. Other non-annotated DEPs may also play vital roles in the male sexual development of M. nipponense. The qPCR analysis indicated that the mRNA expression patterns of the 10 annotated DEPs were consistent with that determined by iTRAQ analysis. Additional qPCR analysis of the 10 DEPs in testes, ovaries, and androgenic glands showed that Gem, Ferritin, and Rev3 were highly expressed in the androgenic gland, implying importance in male sexual development, given the important role of the androgenic gland in male differentiation and development in many crustacean species. Our study provided valuable information about DEPs in androgenic glands between reproductive and nonreproductive seasons for M. nipponense and identified their potential roles in male sexual development, which will improve our understanding of the development process in both M. nipponense and other crustaceans.