Identification of sex determination system and sex‐determining genes have important implications in conservation, ecology and evolution. However, much remains to be discovered about the evolution of different sexual determination systems in teleost fishes, of which the mechanisms of sex determination are remarkably variable. In the present study, the whole genomes of 20 males and 20 females of a Salangid fish, Protosalanx hyalocranius , were sequenced and genome wide association analyses were conducted to uncover its sex determination system and putative sex‐determining genes. A total of 150 SNPs were significantly associated with sex, which showed high differentiation between sexes (F _ST ranged from 0.245 to 0.556). Of the 150 sex‐associated SNPs, 76 SNPs displayed sex specificity with even coverage of depth and were female heterogametic, which suggested a ZZ/ZW sex determination system. Interestingly, one scaffold containing sex‐specific SNPs displayed synteny to the sex chromosome of medaka. Annotations of sex‐associated loci suggested that both transcriptional regulators (e.g., FOX genes) and secreted hormones and their receptors might be involved in the sex determination/differentiation of P. hyalocranius . More strikingly, we found a nonsense mutation in one copy of GALNT homology gene of all females, which suggested that “Z dosage” effect might play a vital role in the processes of sex determination/differentiation. These sex‐specific loci could be a valuable resource for further research on sex determination of Salangid fishes and the results could contribute to the understanding of sex determination mechanisms and the evolution of sex chromosome in teleost fishes.

中文翻译：

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基于Protosalanx hyalocranius的全基因组测序的全基因组关联分析提供了了解塞兰河鱼类性别的见解。

性别决定系统和性别决定基因的鉴定对保护，生态和进化具有重要意义。然而，关于硬骨鱼不同性决定系统的进化，仍有很多发现，其中性决定的机制明显不同。在本研究中，对Salangid鱼Protosalanx hyalocranius的20个雄性和20个雌性的全基因组进行了测序，并进行了全基因组关联分析，以揭示其性别决定系统和假定的性别决定基因。共有150个SNP与性别显着相关，这表明性别之间存在高度差异（F _ST范围从0.245到0.556）。在150个与性别相关的SNP中，有76个SNP表现出性别特异性，深度覆盖均匀，并且是女性异配子，这建议使用ZZ / ZW性别确定系统。有趣的是，一种含有性别特异性SNP的支架与medaka的性染色体具有同义性。性别相关基因座的注释表明，转录调节因子（例如FOX基因）和分泌的激素及其受体都可能参与透明质酸假单胞菌的性别确定/分化。。更惊人的是，我们在所有女性的GALNT同源基因的一个拷贝中发现了一个无意义的突变，这表明“ Z剂量”效应可能在性别确定/分化过程中起着至关重要的作用。这些性别特异性位点可能是进一步研究红毛鱼类性别确定的宝贵资源，其结果可能有助于了解性别确定机制和硬骨鱼性别染色体的进化。