Characterization, expression patterns of molt-inhibiting hormone gene of Macrobrachium nipponense and its roles in molting and growth

Abstract

The oriental river prawn, Macrobrachium nipponense, is an important commercial aquaculture resource in China. In order to overwinter, M. nipponense displays decreased physiological activity and less consumption of energy. Sudden warming would trigger molting and cause an extensive death, resulting in huge economic losses. Therefore, it is of great practical significance to study the molting mechanism of oriental river prawns. Molt-inhibiting hormone gene (MIH) plays a major role in regulating molting in crustaceans. In this study, a full length MIH cDNA of M. nipponense (Mn-MIH) was cloned from the eyestalk. The total length of the Mn-MIH was 925 bp, encoding a protein of 119 amino acids. Tissue distribution analysis showed that Mn-MIH was highly expressed in the eyestalk, and that it had relatively low expression in gill, ovary, and abdominal ganglion. Mn-MIH was detected in all developmental stages, and changed regularly in line with the molting cycle of the embryo and larva. Mn-MIH varied in response to the molting cycle, suggesting that Mn-MIH negatively regulates ecdysteroidogenesis. Mn-MIH inhibition by RNAi resulted in a significant acceleration of molting cycles in both males and females, confirming the inhibitory role of MIH in molting. After long-term RNAi males, but not females had significant weight gain, confirming that Mn-MIH plays an important role in growth of M. nipponense. Our work contributes to a better understanding of the role of Mn-MIH in crustacean molting and growth.

The Crustacean Hyperglycemic Hormone Superfamily: Progress Made in the Past Decade

“…Regardless of the inconsistencies in the results obtained from different species, silencing of MIH expression utilizing MIH dsRNA resulted in a significant acceleration of molt frequencies ( 132 , 203 , 204 ) and elevation of ecdysteroids in the hemolymph ( 203 ), indicating a definite role of MIH in the regulation of crustacean molting and growth.…”

“…Until recently, it was thought that MIH/GIH/MOIH peptides were only expressed in neuronal tissues of the XO-SG system. However, MIH expression has been identified in the heart of the shrimp Litopenaeus vannamei ( 131 ), and in the gill, ovary, and abdominal ganglion of Macrobrachium nipponense , though at relatively lower level than in the eyestalks ( 132 ).…”

“…Data in line with this hypothesis mainly come from the variation of MIH transcript levels throughout the molt cycle. In C. sapidus , L. vannamei , M. nipponense , and Scylla paramamosain , MIH transcript levels were relatively high during the inter-molt stage (stage C), declined gradually in the pre-molt stage (stage D), and then returned to a level similar to that of the inter-molt after molting (stage A/B) ( 111 , 132 , 200 , 201 ). The hemolymph ecdysteroid levels in C. sapidus and L. vannamei displayed a corresponding elevation during pre-molt stage when mih gene expression was low ( 111 , 200 ).…”

Transcriptome Profiling Analysis of the Testis After Eyestalk Ablation for Selection of the Candidate Genes Involved in the Male Sexual Development in Macrobrachium nipponense

“…Knockdown of the expression of GIH by RNA interference (RNAi) promotes the ovarian development in M. nipponense (Qiao et al, 2015). Knockdown of the expression of MIH by RNAi promotes the molting in M. nipponense (Qiao et al, 2018). CHH has been proven to promote testis development in M. nipponense (Jin et al, 2013b).…”

Identification of Candidate Genes of Male Sexual Development From Androgenic Gland in Macrobrachium Nipponense Through Performing Long-reads and Next Generation Transcriptome Sequencing After Eyestalk Ablation

“…Knockdown the expression of GIH by RNAi promote the ovarian development in M. nipponense [31]. Knockdown the expression of MIH by RNAi promote the molting in M. nipponense [32]. CHH has been proven to promote testis development in M. nipponense [33].…”