Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China; Tianjin Fisheries Research Institute, Tianjin, China.
Tianjin Medicine Biotechnology Co, Ltd, Tianjin, China.
Comp Biochem Physiol Part D Genomics Proteomics. 2020 Sep;35:100711. doi: 10.1016/j.cbd.2020.100711. Epub 2020 Jul 9.
Chinese tongue sole (Cynoglossus semilaevis) males and females exhibit great differences in growth rate and appearance. The species is heterogametic (ZW/ZZ) and has sex-reversed "pseudomales" that are genetically female and physiologically male. In this study, we identified eight sex-specific single nucleotide polymorphism (SNP) markers for the sex identification of C. semilaevis by using a combination of genome-wide association study (GWAS) screening and SnaPshot validation. Candidate SNPs were screened using genotyping by sequencing to perform GWAS of the differential SNPs between the sexes of C. semilaevis. The SNP loci were amplified using a multiplex PCR system and detected via SNaPshot, which enables multiplexing of up to 30-40 SNPs in a single assay and ensures high accuracy of the results. The molecular markers detected in our study were used to successfully identify normal males and pseudomales from 45 caught and 40 cultured C. semilaevis specimens. Linkage disequilibrium analysis showed that the eight SNP loci were related to each other, with a strong linkage. Moreover, we investigated the expression of prdm6 mRNA containing a missense SNP and confirmed that the gene is differentially expressed in the gonads of the different sexes of C. semilaevis; the expression of prdm6 mRNA was significantly higher in the males than in the females and pseudomales. This means prdm6 may be related to sex differentiation in C. semilaevis.
中国舌鳎（Cynoglossus semilaevis）的雌雄个体在生长速度和外观上存在显著差异。该物种为异型性染色体（ZW/ZZ），具有性反转的“假雄鱼”，其遗传性别为雌性，生理性别为雄性。在这项研究中，我们通过全基因组关联研究（GWAS）筛选和 SnaPshot 验证相结合，鉴定了 8 个用于中国舌鳎性别鉴定的性别特异性单核苷酸多态性（SNP）标记。通过测序分型对候选 SNP 进行了筛选，以对中国舌鳎雌雄个体间的差异 SNP 进行 GWAS。使用多重 PCR 系统对 SNP 位点进行扩增，并通过 SnaPshot 进行检测，该方法可在单次检测中对多达 30-40 个 SNP 进行多重化，从而确保结果的高度准确性。我们在研究中检测到的分子标记成功地从 45 个捕捞和 40 个养殖的中国舌鳎标本中鉴定出正常雄鱼和假雄鱼。连锁不平衡分析表明，这 8 个 SNP 位点相互关联，具有很强的连锁性。此外，我们研究了含有错义 SNP 的 prdm6 mRNA 的表达情况，并证实该基因在不同性别中国舌鳎的性腺中存在差异表达；prdm6 mRNA 在雄性中的表达明显高于雌性和假雄鱼。这意味着 prdm6 可能与中国舌鳎的性别分化有关。
