College of Life Sciences, State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China.
College of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
Zool Res. 2022 Mar 18;43(2):205-216. doi: 10.24272/j.issn.2095-8137.2021.402.
Red tilapia ( spp ) is one of the most popular fish in China due to its bright red appearance, fast growth rate, and strong adaptability. Understanding the sex determination mechanisms is of vital importance for the selection of all-male lines to increase aquacultural production of red tilapia. In this research, the genetic architecture for sex from four mapping populations ( =1 090) of red tilapia was analyzed by quantitative trait loci (QTL)-seq, linkage-based QTL mapping, and linkage disequilibrium (LD)-based genome-wide association studies. Two genome-wide significant QTL intervals associated with sex were identified on ChrLG1 (22.4-23.9 Mb) and ChrLG23 (32.0-35.9 Mb), respectively. The QTL on ChrLG1 was detected in family 1 (FAM1), FAM2, and FAM4, and the other QTL on ChrLG23 was detected in FAM3 and FAM4. Four microsatellite markers located within the QTL were successfully developed for marker-assisted selection. Interestingly, three ( , , and ) of the 12 candidate genes located near or on the two QTL intervals were abundantly expressed in males, while the remaining genes were more highly expressed in females. Seven genes ( , , , , , , and ) were significantly differentially expressed between the male and female groups. Furthermore, LD block analysis suggested that a cluster of genes on ChrLG23 may participate in regulating sex development in red tilapia. Our study provides important information on the genetic architecture of sex in red tilapia and should facilitate further exploration of sex determination mechanisms in this species.
红罗非鱼（ spp ）因其鲜艳的红色外观、快速的生长速度和较强的适应性而成为中国最受欢迎的鱼类之一。了解性别决定机制对于选择全雄系以增加红罗非鱼的水产养殖产量至关重要。本研究通过数量性状位点（QTL）-seq、基于连锁的 QTL 作图和基于连锁不平衡（LD）的全基因组关联研究，分析了来自红罗非鱼四个作图群体（=1090）的性别遗传结构。在 ChrLG1（22.4-23.9 Mb）和 ChrLG23（32.0-35.9 Mb）上分别鉴定到两个与性别相关的全基因组显著 QTL 区间。ChrLG1 上的 QTL 在 FAM1、FAM2 和 FAM4 中检测到，ChrLG23 上的另一个 QTL 在 FAM3 和 FAM4 中检测到。在 QTL 内成功开发了四个微卫星标记，用于标记辅助选择。有趣的是，位于两个 QTL 区间附近或内部的 12 个候选基因中的 3 个（ 、 、 ）在雄性中大量表达，而其余基因在雌性中表达更高。在雄性和雌性群体之间，有 7 个基因（ 、 、 、 、 、 ）的表达存在显著差异。此外，LD 块分析表明，ChrLG23 上的一群基因可能参与调节红罗非鱼的性别发育。本研究为红罗非鱼性别遗传结构提供了重要信息，应有助于进一步探索该物种的性别决定机制。
