College of Fisheries, Hubei Hongshan Laboratory / Key Lab of Freshwater Animal Breeding, Ministry of Agriculture and Rural Affairs / Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, 266237, China.
BMC Genomics. 2024 Oct 15;25(1):963. doi: 10.1186/s12864-024-10884-0.
The blunt snout bream (Megalobrama amblycephala) is an important economic freshwater fish in China with tender flesh and high nutritional value. With the cultivation of superior new varieties and the expansion of breeding scale, it becomes imperative to employ sex-control technology to cultivate monosexual populations of M. amblycephala, thereby preventing the deterioration of desirable traits. The development of specific markers capable of accurately identifying the sex of M. amblycephala would facilitate the determination of the genetic sex of the breeding population before gonad maturation, thereby expediting the processes of sex-controlled breeding of M. amblycephala.
A whole-genome re-sequencing was performed for 116 females and 141 males M. amblycephala collected from nine populations. Seven candidate male-specific sequences were identified through comparative analysis of male and female genomes, which were further compared with the sequencing data of 257 individuals, and finally three male-specific sequences were generated. These three sequences were further validated by PCR amplification in 32 males and 32 females to confirm their potential as male-specific molecular markers for M. amblycephala. One of these markers showed potential applicability in M. pellegrini as well, enabling males to be identified using this specific molecular marker.
The study provides a high-efficiency and cost-effective approach for the genetic sex identification in two species of Megalobrama. The developed markers in this study have great potential in facilitating sex-controlled breeding of M. amblycephala and M. pellegrini, while also contributing valuable insights into the underlying mechanisms of fish sex determination.
团头鲂（Megalobrama amblycephala）是中国重要的淡水经济鱼类，肉质细嫩，营养价值高。随着优良新品种的培育和养殖规模的扩大，迫切需要采用性别控制技术培育团头鲂的单性种群，从而防止优良性状的恶化。开发能够准确识别团头鲂性别的特异性标记物，将有助于在性腺成熟前确定养殖群体的遗传性别，从而加速团头鲂的性别控制育种过程。
对来自 9 个群体的 116 只雌性和 141 只雄性团头鲂进行了全基因组重测序。通过雌雄基因组的比较分析，鉴定出 7 个候选的雄性特异性序列，进一步与 257 个个体的测序数据进行比较，最终得到 3 个雄性特异性序列。这些三个序列通过在 32 只雄性和 32 只雌性中进行 PCR 扩增进一步验证，证实它们有潜力成为团头鲂的雄性特异性分子标记。其中一个标记在 M. pellegrini 中也具有潜在的适用性，可以使用该特异性分子标记鉴定雄性。
本研究为两种团头鲂的遗传性别鉴定提供了一种高效、经济的方法。本研究开发的标记物在团头鲂和 M. pellegrini 的性别控制育种中具有很大的应用潜力，同时也为鱼类性别决定的潜在机制提供了有价值的见解。
