Pacific white shrimp (Litopenaeus vannamei) vitellogenesis-inhibiting hormone (VIH) is predominantly expressed in the brain and negatively regulates hepatopancreatic vitellogenin (VTG) gene expression.
Ovarian maturation in crustaceans is temporally orchestrated by two processes: oogenesis and vitellogenesis. The peptide hormone vitellogenesis-inhibiting hormone (VIH), by far the most potent negative regulator of crustacean reproduction known, critically modulates crustacean ovarian maturation by suppressing vitellogenin (VTG) synthesis. In this study, cDNA encoding VIH was cloned from the eyestalk of Pacific white shrimp, Litopenaeus vannamei, a highly significant commercial culture species. Phylogenetic analysis suggests that L. vannamei VIH (lvVIH) can be classified as a member of the type II crustacean hyperglycemic hormone family. Northern blot and RT-PCR results reveal that both the brain and eyestalk were the major sources for lvVIH mRNA expression. In in vitro experiments on primary culture of shrimp hepatopancreatic cells, it was confirmed that some endogenous inhibitory factors existed in L. vannamei hemolymph, brain, and eyestalk that suppressed hepatopancreatic VTG gene expression. Purified recombinant lvVIH protein was effective in inhibiting VTG mRNA expression in both in vitro primary hepatopancreatic cell culture and in vivo injection experiments. Injection of recombinant VIH could also reverse ovarian growth induced by eyestalk ablation. Furthermore, unilateral eyestalk ablation reduced the mRNA level of lvVIH in the brain but not in the remaining contralateral eyestalk. Our study, as a whole, provides new insights on VIH regulation of shrimp reproduction: 1) the brain and eyestalk are both important sites of VIH expression and therefore possible coregulators of hepatopancreatic VTG mRNA expression and 2) eyestalk ablation could increase hepatopancreatic VTG expression by transcriptionally abolishing eyestalk-derived VIH and diminishing brain-derived VIH.
Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
Ting
T
Chen
Lv-Ping
LP
Zhang
Nai-Kei
NK
Wong
Ming
M
Zhong
Chun-Hua
CH
Ren
Chao-Qun
CQ
Hu
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001923:Brain Chemistry / Q000502:physiology*; D002352:Carrier Proteins / Q000096:biosynthesis / Q000502:physiology*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics* / Q000502:physiology*; D006458:Hemolymph / Q000737:chemistry / Q000378:metabolism; D043143:Hepatopancreas / Q000166:cytology / Q000378:metabolism*; D007447:Invertebrate Hormones / Q000096:biosynthesis / Q000502:physiology*; D008297:Male; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000502:physiology*; D061251:Primary Cell Culture; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D012679:Sense Organs / Q000502:physiology; D014018:Tissue Distribution; D014819:Vitellogenins / Q000096:biosynthesis* / Q000235:genetics*
D002352:Carrier Proteins; D007447:Invertebrate Hormones; D011994:Recombinant Proteins; D014819:Vitellogenins; C073189:vitellogenesis inhibiting hormone
VIH; VTG; brain; eyestalk ablation; hepatopancreas; reproduction; shrimp