The Pacific white shrimp Litopenaeus vannamei is one of the major economic aquaculture species. The growth trait is considered as the most important trait in L. vannamei aquaculture. Identification of the genetic components underlying growth-related traits in L. vannamei could be useful for the selective breeding of growth trait. Our previous work identified several growth-related SNPs by genome-wide association study (GWAS). Based on the assembled genome, we identified a new candidate gene (LvMMD2) beside the associated marker. This gene encodes the progestin and AdipoQ receptor 10 (PAQR10) protein. We further investigate the polymorphisms of LvMMD2 and their association with body weight of L. vannamei. By resequencing the coding region of LvMMD2, a total of 8 SNPs were identified, including 6 synonymous mutations and 2 nonsynonymous mutations. Association analyses based on a population of 322 individuals revealed that several SNPs located in the coding region of LvMMD2 were significantly associated with the body weight, especially the nonsynonymous mutation named as MMD_5 contributed the most association to the trait and it could explain 10.5% of phenotypic variance. In addition, several genes involved in growth and development have been identified as LvMMD2-interacting genes. These findings strongly suggested that LvMMD2 might be an important gene regulating the shrimp growth. More importantly, the MMD_5 could be a promising candidate locus for marker-assisted selection (MAS) of the body weight in L. vannamei.

中文翻译：

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南美白对虾LvMMD2的多态性及其与生长性状的关联。

太平洋白虾南美白对虾是主要的经济养殖品种之一。生长性状被认为是南美白对虾养殖中最重要的性状。鉴定南美白对虾生长相关性状的遗传成分可能有助于生长性状的选择性育种。我们之前的工作通过全基因组关联研究 (GWAS) 确定了几个与生长相关的 SNP。基于组装的基因组，我们在相关标记旁边鉴定了一个新的候选基因（LvMMD2）。该基因编码孕激素和 AdipoQ 受体 10 (PAQR10) 蛋白。我们进一步研究了LvMMD2的多态性及其与体重的关联南美白对虾。通过对LvMMD2的编码区进行重测序，共鉴定出8个SNP，包括6个同义突变和2个非同义突变。基于 322 个人的关联分析显示，位于LvMMD2编码区的几个 SNP与体重显着相关，尤其是名为 MMD_5 的非同义突变与该性状的关联最大，它可以解释 10.5% 的表型方差。此外，一些涉及生长和发育的基因已被鉴定为LvMMD2相互作用基因。这些发现强烈表明LvMMD2可能是调节虾生长的重要基因。更重要的是，MMD_5 可能是南美白对虾体重的标记辅助选择（MAS）候选位点。