Molt-inhibiting hormone (MIH), a neuropeptide synthesized in the eyestalk in crustaceans, is mainly responsible for the molting by negatively controlling the ecdysteroids secretion. Although there are several reports of the isolation and protein sequencing of MIH in the red swamp crayfish, little is known about the nucleotide sequence and gene organization of this neuropeptide, even less about the association of MIH polymorphisms and growth traits. Here, a 1237 bp full-length MIH cDNA was obtained from the crayfish eyestalk, which encodes a putative protein of 106 amino acids, with a 191 bp 5′-UTR and a 728 bp 3′-UTR. The MIH genomic DNA sequence is 4205 bp in length, which includes three exons interrupted by two introns, and a 929 bp 5′-flanking region. Potential transcription initiation site and transcription factor binding sites were identified in the 5′-flanking region, implying a potential role in transcriptional regulation. Seventeen SNPs in the 5′-flanking region and 3′-UTR were identified, and the associations between these SNPs and growth traits were evaluated with a two-stage design. A SNPs g. -12C > G that showed a significant association with body weight was identified. Individuals with GG genotype had a significantly higher body weight than those with CC genotype (43.98 ± 9.82 g vs. 34.27 ± 6.87 g; P ﹤ 0.001), indicating a beneficial effect of the G allele on the growth of red swamp crayfish. The obtained MIH gene, as well as the identified SNPs, may serve as targets for molecular marker-aided selection in growth improvement of the red swamp crayfish in future studies.

蜕皮抑制激素（MIH）是甲壳类动物在视线中合成的一种神经肽，主要通过消极地控制蜕皮激素的分泌来引起蜕皮。尽管有关于红沼泽小龙虾中MIH的分离和蛋白质测序的报道，但对该神经肽的核苷酸序列和基因组织了解甚少，甚至对MIH多态性与生长性状的关联了解甚少。在这里，从小龙虾的眼柄中获得了一个1237 bp的全长MIH cDNA，该蛋白编码一个106个氨基酸的推定蛋白，具有191 bp的5'-UTR和728 bp的3'-UTR。该MIH基因组DNA序列的长度为4205 bp，包括三个被两个内含子打断的外显子，以及一个929 bp的5'侧翼区域。在5'侧翼区域中鉴定了潜在的转录起始位点和转录因子结合位点，这暗示了在转录调控中的潜在作用。在5'侧翼区域和3'-UTR中鉴定了17个SNP，并通过两阶段设计评估了这些SNP与生长性状之间的关联。一个SNP g。鉴定出与体重显着相关的-12C>G。GG基因型个体的体重显着高于CC基因型个体（43.98±9.82 g vs. 34.27±6.87 g； P ﹤0.001），表明G等位基因对红色沼泽小龙虾的生长具有有益作用。获得的MIH基因以及已鉴定的SNPs可以作为分子标记辅助选择的目标，以在未来的研究中改善红沼泽小龙虾的生长。