AUTHOR=Liu An , Shi Wenyuan , Lin Dongdong , Ye Haihui 

TITLE=A Possible Role of Allatostatin C in Inhibiting Ecdysone Biosynthesis Revealed in the Mud Crab Scylla paramamosain

JOURNAL=Frontiers in Marine Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2021.740251

DOI=10.3389/fmars.2021.740251

ISSN=2296-7745

ABSTRACT=<p>C-type allatostatins (C-type ASTs) are a family of structurally related neuropeptides found in a wide range of insects and crustaceans. To date, the C-type allatostatin receptor in crustaceans has not been deorphaned, and little is known about its physiological functions. In this study, we aimed to functionally define a C-type ASTs receptor in the mud crab, <italic>Scylla paramamosian</italic>. We showed that C-type ASTs receptor can be activated by <italic>Scypa</italic>AST-C peptide in a dose-independent manner and by <italic>Scypa</italic>AST-CCC peptide in a dose-dependent manner with an IC<sub>50</sub> value of 6.683 nM. Subsequently, <italic>in vivo</italic> and <italic>in vitro</italic> experiments were performed to investigate the potential roles of <italic>Scypa</italic>AST-C and <italic>Scypa</italic>AST-CCC peptides in the regulation of ecdysone (20E) and methyl farnesoate (MF) biosynthesis. The results indicated that <italic>Scypa</italic>AST-C inhibited biosynthesis of 20E in the Y-organ, whereas <italic>Scypa</italic>AST-CCC had no effect on the production of 20E. In addition, qRT-PCR showed that both <italic>Scypa</italic>AST-C and <italic>Scypa</italic>AST-CCC significantly decreased the level of expression of the MF biosynthetic enzyme gene in the mandibular organ, suggesting that the two neuropeptides have a negative effect on the MF biosynthesis in mandibular organs. In conclusion, this study provided new insight into the physiological roles of AST-C in inhibiting ecdysone biosynthesis. Furthermore, it was revealed that AST-C family peptides might inhibit MF biosynthesis in crustaceans.</p>