Yang Junyi, Zhou Zhixiong, Pu Fei, Zhou Tao, Xu Peng
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, China; Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
Gene. 2022 Oct 5;840:146769. doi: 10.1016/j.gene.2022.146769. Epub 2022 Jul 27.
The solute carrier family 9 (slc9) genes, especially slc9a isoform coding proteins contribute to electroneutral countertransport of H for Na across the plasmalemmal and organellar membranes, intracellular pH and cellular volume regulation as well as the electrolyte, acid-base, and fluid volume homeostasis at the systemic level. These functional properties determine a potential basis for organisms to challenge stressful conditions. However, these well-done researches have been reported more in mammals. Thus, in this study, a total of eleven slc9 genes were identified from the latest version genome of L. waleckii, a cyprinid fish that could tolerate extremely alkaline environments (pH 9.6). The evolutionary footprint of slc9 genes was uncovered via the analysis of copy numbers, gene structure, motif composition, chromosome location and phylogenetic relationship. More importantly, there were two SNPs located on 5' UTR and three non-synonymous mutations in the coding region of the slc9a3.2 gene by comparing freshwater with alkaline water populations attached to resequencing technology. Slc9a3.2 gene was a statistically significant low expression in gill tissue with extremely alkaline pressure. Generally, slc9 gene family in L. waleckii was highly conserved. Several important SNPs with high Fst values were identified where non-synonymous mutations occurred between freshwater and alkaline water populations, and they may play an important role in specific functional differentiation. Slc9 genes had clear tissue expression preferences and were involved in abiotic stress response, indicating their roles in physiological function and strong self-regulating capacity. Our insight into the genetic variations that take place in the individual genes under extreme conditions could provide a feasible example for studying specific molecular mechanisms based on genomic data with increasing environmental stress.
溶质载体家族9（slc9）基因，尤其是编码slc9a亚型的蛋白质，有助于H与Na在质膜和细胞器膜上进行电中性反向转运，调节细胞内pH值和细胞体积，以及在系统水平上维持电解质、酸碱和液体体积的稳态。这些功能特性为生物体应对压力条件奠定了潜在基础。然而，这些深入的研究在哺乳动物中报道得更多。因此，在本研究中，从能够耐受极端碱性环境（pH 9.6）的鲤科鱼类瓦氏雅罗鱼的最新版本基因组中总共鉴定出11个slc9基因。通过分析基因拷贝数、基因结构、基序组成、染色体定位和系统发育关系，揭示了slc9基因的进化印记。更重要的是，通过对淡水群体和碱性水群体进行重测序技术比较，发现slc9a3.2基因的5' UTR上有两个单核苷酸多态性（SNP），编码区有三个非同义突变。在极端碱性压力下，slc9a3.2基因在鳃组织中的表达具有统计学意义的低水平。总体而言，瓦氏雅罗鱼中的slc9基因家族高度保守。在淡水群体和碱性水群体之间发生非同义突变的位置鉴定出了几个具有高Fst值的重要SNP，它们可能在特定的功能分化中起重要作用。Slc9基因具有明确的组织表达偏好，并参与非生物胁迫反应，表明它们在生理功能和强大的自我调节能力方面发挥作用。我们对极端条件下单个基因发生的遗传变异的深入了解，可以为基于环境压力增加的基因组数据研究特定分子机制提供一个可行的例子。
