Sex dimorphism of economic traits such as growth rate and body size have potential breeding value in aquaculture. Largemouth bass (Micropterus salmoides L.) is an important freshwater cultured fish in China and the females live longer and reach larger sizes than males. However, the lacking of sex-specific makers and the unclear sex determination mechanism inhibits the development of all-female breeding. In this study, 5 females and 5 males were randomly selected and sequenced with whole-genome re-sequencing technology. In total, 1394 filtered SNPs and 425 filtered InDels were finally identified, and most of these makers were located at Chr7 and Chr18. The validation of the 35 SNPs located at Chr7 in three distinct population (n = 72) indicated that 2 SNPs (S4 and S6) could distinguish the females and males with 100% accuracies, which were genotyped as CC and CG, AA and AT in the females and males, respectively. Further, 10 and 6 InDels with sizes more than 18 bp were finally screened out on Chr7 and Chr18. 2 male-specific InDels (rs3394676 and rs3496814) located at Chr7 could effectively distinguish the above females and males with a PCR-based agarose gel electrophoresis, which performed as one band in the females and two bands in the males, respectively. These results suggested the Chr7 might be the sex chromosome and a XX/XY sex determination system in largemouth bass. In conclusion, a whole-genome re-sequencing method was first conducted to provide usefulness sex-specific makers and a XX/XY sex determination system in largemouth bass, which contributes to study of the sex determination mechanisms and the development of mono-sex population breeding.

生长速度、体型等经济性状的性别二态性在水产养殖中具有潜在的育种价值。大口黑鲈（Micropterus salmoides L.）是我国重要的淡水养殖鱼类，雌性寿命长，体型比雄性大。然而，性别特异性标记者的缺乏和性别决定机制的不明确阻碍了全雌性育种的发展。本研究随机选取5女5男，采用全基因组重测序技术进行测序。最终共鉴定出 1394 个过滤的 SNP 和 425 个过滤的 InDels，其中大部分标记位于 Chr7 和 Chr18。在三个不同群体中位于 Chr7 的 35 个 SNP 的验证 ( n = 72）表明2个SNP（S4和S6）可以100％的准确率区分雌性和雄性，它们在雌性和雄性中分别被基因分型为CC和CG，AA和AT。此外，最终在 Chr7 和 Chr18 上筛选出大小超过 18 bp 的 10 和 6 个 InDel。位于 Chr7 的 2 个雄性特异性 InDels（rs3394676 和 rs3496814）可以通过基于 PCR 的琼脂糖凝胶电泳有效区分上述雌性和雄性，分别表现为雌性一条带和雄性两条带。这些结果表明 Chr7 可能是大口黑鲈的性染色体和 XX/XY 性别决定系统。总之，首先进行了全基因组重测序方法，以在大口黑鲈中提供有用的性别特异性标记和 XX/XY 性别确定系统，