Xu Pingrui, Xiao Yongshuang, Dong Junde, Xiao Zhizhong, Li Jun, Wang Yanfeng
College of Life Sciences, Qingdao Agricultural University, Qingdao, China.
Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture (CAS), Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
Mar Biotechnol (NY). 2024 Dec 20;27(1):22. doi: 10.1007/s10126-024-10403-y.
Spotted knifejaw (Oplegnathus punctatus) is an economically important marine cultured species exhibiting a unique complex sex chromosome system (XXXX in females and XXY in males), with males possessing one fewer chromosome (2n = 47) than females (2n = 48) and an abnormally large Y chromosome. Additionally, males demonstrate significant growth advantages over females. Rapid and accurate sex identification is essential for effective culture management, selective breeding, and population control. In this study, we identified a homologous region of the tmem88 gene containing large DNA insertion markers on the X and Y chromosomes through whole-genome sequencing of O. punctatus. The X chromosome harbors a 278 bp DNA fragment, whereas the Y chromosome contains a 1472 bp fragment, resulting in a 1194 bp size difference indicative of structural variation in the non-coding region of the tmem88 gene. We developed a rapid detection method based on this variation, utilizing a pair of primers that amplify two distinct bands (278 bp and 1472 bp) in male (XXY) individuals and a single 278 bp band in female (XXXX) individuals when analyzed by agarose gel electrophoresis. This method enables efficient and accurate sex differentiation in O. punctatus, significantly reducing the time required for identification and enhancing detection efficiency. This study provides a valuable tool for the rapid identification of sex in O. punctatus, facilitating improved breeding strategies and supporting the large-scale production of high-quality fry.
斑石鲷（Oplegnathus punctatus）是一种具有重要经济价值的海水养殖鱼类，其具有独特的复杂性别染色体系统（雌性为XXXX，雄性为XXY），雄性比雌性少一条染色体（2n = 47），且Y染色体异常大。此外，雄性比雌性具有显著的生长优势。快速准确的性别鉴定对于有效的养殖管理、选择性育种和种群控制至关重要。在本研究中，我们通过斑石鲷的全基因组测序，在X和Y染色体上鉴定出了包含大DNA插入标记的tmem88基因同源区域。X染色体含有一个278 bp的DNA片段，而Y染色体含有一个1472 bp的片段，导致1194 bp的大小差异，这表明tmem88基因非编码区存在结构变异。我们基于这种变异开发了一种快速检测方法，利用一对引物，通过琼脂糖凝胶电泳分析时，在雄性（XXY）个体中扩增出两条不同的条带（278 bp和1472 bp），而在雌性（XXXX）个体中扩增出一条单一的278 bp条带。该方法能够高效准确地对斑石鲷进行性别区分，显著减少鉴定所需时间并提高检测效率。本研究为斑石鲷的快速性别鉴定提供了一种有价值的工具，有助于改进育种策略并支持高质量鱼苗的大规模生产。
