Abstract The blue tilapia (Oreochromis aureus) is an important cultured fish worldwide, and exhibits sexual size dimorphism in favor of males, and therefore, mono-sex breeding is of great value for aquaculture. However, the lack of accurate sex-linked markers for blue tilapia has hampered the mono-sex culture in aquaculture, as well as study of sex determination in this species. In this study, WW super-females were bred and selected. Then, structure variations between WW and ZZ in sex determining region were identified from blue tilapia by comparative analysis of ZZ/ZW genome re-sequencing data from 5 different strains and ZZ/WW reference genome sequences. Based on these structure variations, 30 pairs of primers were designed to screen sex-linked markers. After two rounds of PCR screening, three markers, named as Marker-1, Marker-2 and Marker-3, were obtained to identify the genetic sex of blue tilapia. Marker-2 and Marker-3 were combined together for multiplex PCR amplification to distinguish ZZ, ZW and WW fish to make up for the lack of a co-dominant marker. In conclusion, three sex-linked markers were isolated and used for identification of different genotypes and establishment of MAS-GMT (marker-assisted selection of genetically male tilapias) technique in blue tilapia. It is also of great significance for isolation of sex determining gene, elucidation of the evolution of sex chromosomes and the transition of sex determination system.

中文翻译：

---

蓝罗非鱼 (Oreochromis aureus) 中性连锁 DNA 标记的筛选和表征和标记辅助选择

摘要 蓝罗非鱼（Oreochromis aureus）是世界范围内重要的养殖鱼类，存在有利于雄性的性别大小二态性，因此单性繁殖对水产养殖具有重要价值。然而，由于缺乏准确的蓝罗非鱼性别相关标记，阻碍了水产养殖中的单性养殖以及该物种性别决定的研究。在这项研究中，培育和选择了 WW 超级雌性。然后，通过比较分析来自 5 个不同品系的 ZZ/ZW 基因组重测序数据和 ZZ/WW 参考基因组序列，从蓝罗非鱼中鉴定出性别决定区 WW 和 ZZ 之间的结构变异。基于这些结构变化，设计了 30 对引物来筛选性连锁标记。经过两轮 PCR 筛选，三个标记，分别命名为 Marker-1、Marker-2 和 Marker-3，获得用于鉴定蓝罗非鱼的遗传性别。Marker-2 和 Marker-3 组合在一起进行多重 PCR 扩增，以区分 ZZ、ZW 和 WW 鱼，以弥补共显性标记的不足。总之，分离出三个性连锁标记，用于鉴定蓝罗非鱼的不同基因型和建立 MAS-GMT（遗传雄性罗非鱼的标记辅助选择）技术。对分离性别决定基因、阐明性染色体的进化和性别决定系统的转变也具有重要意义。分离出三个性连锁标记，用于鉴定蓝罗非鱼的不同基因型和建立MAS-GMT（遗传雄性罗非鱼的标记辅助选择）技术。对分离性别决定基因、阐明性染色体的进化和性别决定系统的转变也具有重要意义。分离出三个性连锁标记，用于鉴定蓝罗非鱼的不同基因型和建立MAS-GMT（遗传雄性罗非鱼的标记辅助选择）技术。对分离性别决定基因、阐明性染色体的进化和性别决定系统的转变也具有重要意义。