题目：Differential regulation of hepatopancreatic vitellogenin (VTG) gene expression by two putative molt-inhibiting hormones (MIH1/2) in Pacific White Shrimp (Litopenaeus vannamei)

作者: Xing Luo#,Ting Chen#,Ming Zhong,Xiao Jiang,Lvping Zhang,Chunhua Ren,Chaoqun Hu*

刊物: Peptides

刊号: 2015,68:58-63

摘要: Molt-inhibiting hormone(MIH), a peptide member of the crustacean hyperglycemic hormone(CHH) family, is commonly considered as a negative regulator during the molt cycle in crustaceans. Phylogenetic analysis of CHH family peptides in penaeidae shrimps suggested that there is no significant differentiation between MIH and vitellogenesis-inhibiting hormone (VIH, another peptide member of CHH family), by far the most potent negative regulator of crustacean vitello genes is known. Thus, MIH may also play a  role in regulating vitello genesis. In this study, two previously reported putative MIHs (LivMIH1 and LivMIH2) in the Pacific white shrimp (Litopenaeus vannamei)  were expressed in Escherichia coli, purified by immobilized metalion affinity chromatography(IMAC) and further confirmed by western blot. Regulation of vitellogenin (VTG) mRNA expression by recombinant LivMIH1 and LivMIH2 challenge was performed by both in vitro hepatopancreatic primary cells culture and in vivo injection approaches. In in vitro primary culture of shrimp hepatopancreatic cells,only LivMIH2 but not LivMIH1 administration could improve the mRNA expression of VTG. In in vivo injection experiments, similarly, only LivMIH2 but not LivMIH1 could  stimulate hepatopancreatic VTG gene expression and induce ovary maturation. Our study may provide evidence for one is of or mofMIH (MIH2in L. vannamei) may serve as one of the mediators of the physiological progress of molting and vitellogenesis. Our study may also give new insight in CHH family peptides regulating reproduction in crustaceans, inparticular penaeidae shrimps