Molting is the important physiological process in Macrobrachium rosenbergii. This work is aimed to explore the endocrine regulation of M. rosenbergii and the expression patterns of related genes in the molting pathway, and to reveal the molecular regulatory pathways of M. rosenbergii molting. The activities of molt-related enzymes（glutamine synthetase, β-N acetylglucosaminidase and chitinase）and ecdyhormone contents in the molting cycle of hepatopancreas and hemolymph in M. rosenbergii were determined, and the expressions of Mr-ETHR, Mr-FTZ-F1, Mr-ECR, Mr-RXR, and Mr-MIH were detected by RT-qPCR. The results of enzymatic activity showed that glutamine synthetase was more active in hemolymphatic than in hepatopancreatic（P<0.05）. β-N acetylglucosaminidase had much higher pre-molting activity in hepatopancreatic and hemolymphatic than in the postmolt stage（P<0.05）. In the hepatopancreas, chitinase activity was the highest in the postmolt stage（P<0.05）. The content of ecdytropin in the hepatopancreatic and hemolymphatic was the lowest in the intermolt stage and the highest in the postmolt stage. The ORF length of Mr-ETHR gene was 1 173 bp, encoding 390 amino acids, and the sequence was relatively conserved. The ORF length of Mr-FTZ-F1 gene was 1 206 bp, encoding 401 amino acids. The Mr-ETHR, Mr-RXR and Mr-ECR expressed the highest in the postmolt stage, while Mr-FTZ-F1 was the highest in the premolt stage. The expressions of Mr-MIH reached the highest in the intermolt stage and the lowest in the postmolt stage. Cluster and correlation analyses showed that Mr-ETHR and Mr-RXR and Mr-ECR expression patterns were closely related and had a very significant positive correlation（r=0.7030, P<0.01; r=0.8680, P<0.01）, Mr-FTZ-F1 and Mr-MIH expression patterns were similar and positively correlated（r=0.6665, P<0.01）, while Mr-FTZ-F1 was negatively correlated with Mr-ECR and Mr-ETHR（r=-0.8339, P<0.01; r=-0.6275, P<0.01）. It was shown that the molting process of R. rosenbergii was regulated by glutamine synthetase, β-N-acetylaminoglucosidase and chitinase, and Mr-ETHR, Mr-RXR, Mr-ECR, Mr-FTZ-F1 and Mr-MIH were involved in regulating the molting process of M. rosenbergii, and Mr-ETHR, Mr-RXR and Mr-ECR were positively regulated in the molting signaling pathway, while Mr-FTZ-F1 and Mr-MIH were negatively regulated. Mr-ETHR, Mr-RXR and Mr-ECR play a positive regulatory role in the molt signaling pathway, while Mr-FTZ-F1 and Mr-MIH play a negative regulatory role. This study's results provided a foundation for the study of molting regulation mechanism in the downstream of the molting signaling pathway in crustaceans.
