State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, College of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
Mar Biotechnol (NY). 2019 Apr;21(2):250-261. doi: 10.1007/s10126-019-09877-y. Epub 2019 Feb 8.
Understanding the genetic mechanism of osmoregulation is important for the improvement of salt tolerance in tilapia. In our previous study, we have identified a major quantitative trait locus (QTL) region located at 23.0 Mb of chrLG18 in a Nile tilapia line by QTL-seq. However, the conservation of these QTLs in other tilapia populations or species is not clear. In this study, we successfully investigated the QTLs associated with salt tolerance in a mass cross population from the GIFT line of Nile tilapia (Oreochromis niloticus) using a ddRAD-seq-based genome-wide association study (GWAS) and in a full-sib family from the Malaysia red tilapia strain (Oreochromis spp) using QTL-seq. Our study confirmed the major QTL interval that is located at nearly 23.0 Mb of chrLG18 in Nile tilapia and revealed a long QTL cluster across chrLG18 controlling for the salt-tolerant trait in both red tilapia and Nile tilapia. This is the first GWAS analysis on salt tolerance in tilapia. Our finding provides important insights into the genetic architecture of salinity tolerance in tilapia and supplies a basis for fine mapping QTLs, marker-assisted selection, and further detailed functional analysis of the underlying genes for salt tolerance in tilapia.
了解渗透压调节的遗传机制对提高罗非鱼的耐盐性很重要。在我们之前的研究中，通过 QTL-seq，我们在尼罗罗非鱼品系中鉴定出一个位于 chrLG18 上 23.0Mb 的主要数量性状位点（QTL）区域。然而，这些 QTL 在其他罗非鱼种群或物种中的保守性尚不清楚。在这项研究中，我们成功地通过基于 ddRAD-seq 的全基因组关联研究（GWAS）在尼罗罗非鱼 GIFT 系的大规模杂交群体中，以及在马来西亚红罗非鱼品系的全同胞家系中，利用 QTL-seq 研究了与耐盐性相关的 QTLs。我们的研究证实了在尼罗罗非鱼中位于 chrLG18 上近 23.0Mb 的主要 QTL 区间，并揭示了一个横跨 chrLG18 的长 QTL 簇，控制着红罗非鱼和尼罗罗非鱼的耐盐性状。这是罗非鱼耐盐性的首次 GWAS 分析。我们的发现为罗非鱼耐盐性的遗传结构提供了重要的见解，并为 QTL 的精细定位、标记辅助选择以及罗非鱼耐盐性相关基因的进一步详细功能分析提供了基础。
