ITRAQ‐based quantitative proteomic analysis reveals metabolic changes in overwintering Scylla paramamosain at two different salinities

Abstract

Scylla paramamosain is one of the commercially crucial marine crustaceans belonging to the genus Scylla, which is commonly distributed along the coasts of China. Proteomic data are scarce for the mud crab. Salinity is one of the ecological factors that affect S. paramamosain during overwintering. To understand the energy metabolism mechanism adapted to salinity, we analysed the proteomics of S. paramamosain hepatopancreas in response to two different salinities (4‰ and 25‰). A total of 1283 proteins were detected, of which 426 down-regulated proteins and 83 up-regulated proteins were associated with metabolism (p < 0.05). Among these proteins related to metabolic pathways (16 pathways), we identified angiotensin-converting enzyme, trypsin, glutamate dehydrogenase, aminomethyl transferase, hexokinase, pyruvate kinase, glucose-6-phosphate dehydrogenase, L-lactate dehydrogenase, superoxide dismutase, alkaline phosphatase, catalase and xanthine dehydrogenases. Additionally, real-time PCR showed mRNA expression of differentially expressed genes correlated positively with their protein levels. Compared with 25‰ salinity group, 4‰ salinity group was involved in amino acid metabolism, carbohydrate metabolism, energy metabolism, lipid metabolism and inorganic ion metabolism by regulating related proteins, which made the metabolism of the overwintering S. paramamosain more vigorous in the low salt environment, and hepatopancreas consumed more energy to maintain life activities. These data are the first to reveal the molecular mechanism of overwintering S. paramamosain in response to different salinities at the protein level. The study provides important information for the aquaculture production of S. paramamosain during indoor overwintering.