瓦氏雅罗鱼属广盐性淡水鱼类，分布于黑龙江、辽河、黄河水系。而生存于内蒙古达里诺尔中的瓦氏雅罗鱼，可在pH9.6，碱度达53.57mM的水质环境下生存。其机体与渗透压调节相关的鳃、肾等组织在应对环境离子变化，维持机体渗透压平衡所表现的超强能力有别于淡水种群。推测该种群在数千年内随着湖泊由淡向半咸水演化过程中受环境胁迫，并经世代适应性选择进化获得耐高碱性状。本研究以瓦氏雅罗鱼碱水和淡水种群为研究对象，依托已完成的雅罗鱼转录组测序结果，从组织学、生理生化、基因组学水平上对实验鱼鳃、肾、血液和基因组DNA进行分析，寻找不同盐碱环境下两个种群存在的差异，并建立相关性；同时对各种群进行基因组重测序，获得耐高碱种群中受到高碱环境正向选择的基因，进行定位和功能验证。同时与台湾研究团队合作，就瓦氏雅罗鱼高碱环境下离子调控机制进行合作研究。从遗传多样性、环境适应性进化等诸方面，为耐盐碱鱼类新品种培育奠定基础。

Leuciscus waleckii is a euryhaline, cold freshwater cyprinid fish, and primarily distributes in water regions around the Amur River, a few areas in the Liao River and the Yellow River, as well as inland lakes in Inner Mongolia around China. One unique feature of this fish is its resistance to high alkalinity, which allows it to survive and adapt to Dali Lake, which is a extremely alkaline lake with a HCO3-/CO32- concentration over 53.57 mM (pH 9.6). Its ability to tolerate high alkalinity is different from its freshwater counterpart, especially as shown in strong adaption of gill and kidney that maintain the balance of osmotic pressure and ion regulation in response to the extreme environment. With the Dalinor evolves from freshwater to brackish lake since the Holocene, L. waleckii is speculated to gain of alkali-tolerant trait by way of the generations of adaptive selection. In this study, based on the results of early completion of Leuciscus transcriptome sequencing, we will continue to identify the interested differences involved in histology, physiology, biochemistry and genomic level between L. waleckii Dalinuoer populations and freshwater populations, to construct the correlation between the difference detected with extreme alkali adaptation, to find genes under positive selection of extreme alkali environment through re-sequencing of different populations as well as provide the evidence of gene position and function. At the same time, we will cooperate with the team of Taiwan Central Research Institute of Cell and Molecular Biology of the Individual, as genetic diversity, the evolution of environmental adaptability, among others. These works will impress the knowledge of the characteristics of L. waleckii and provide necessary basic research for new varieties breeding with saline and alkali tolerance.

雅罗鱼属鱼类属广盐性鱼类，淡水、碱水、海水水域均有雅罗鱼分布，具不完全统计世界范围内共有34种。在我国境内河流和湖泊中生存的瓦氏雅罗鱼就有多个地理种群。它们对盐碱的耐受能力存在显著的差异，这为开展鱼类离子调控机制和耐碱功能基因发掘提供了良好的实验材料。本项目利用瓦氏雅罗鱼淡水种和碱水种分别从组织生理生化、基因表达、基因组学等不同角度对其开展了研究，为从不同层面完整解析瓦氏雅罗鱼耐高碱的生理和分子机制奠定了基础。（1）雅罗鱼碱水种和淡水种鳃组织的微观结构比较，发现由于长期的地理隔离以及栖息环境的不同，碱水种和淡水种在鳃组织结构方面发生了巨大改变。碱水种鳃组织结构与海水鱼类相似，离子细胞表面微绒毛减少、氯细胞数显著增加；（2）血液生理生化指标比较发现，碱水种和淡水种在尿素氮、总碱度含量方面存在明显差异，在相同碱度胁迫下，碱水种的尿素氮含量增加，总碱度维持不变，而淡水种尿素氮含量下降，总碱度含量增加，说明碱水种具有特殊的排氨和排碱机制；（3）通过分析碱水种在不同碱度处理下的氨氮排泄率、血氨含量及血浆游离氨基酸(PFAAs)含量变化趋势，弄清了碱水种在高碱条件下的排氨策略，即，启动部分排氨，并将体内积累的毒氨转换为无毒的PFAAs用于能量供应，从而实现高碱环境的长期适应。（4）调取了排氨Rh和排碱基因家族Slc26的全长cDNA序列，从基因定量表达、免疫组化以及Crispr/Cas9基因编辑技术等对这两个基因家族的功能进行了初探；（5）估算了雅罗鱼碱水种基因组大小约为780M，遗传组成简单；构建了25个遗传连锁图谱，定位了39个与耐碱性状相关的SNP标记；发现了51个基因组区间受到盐碱适应正选择，涉及离子转运、细胞间粘连、死亡、生长等生物学过程。同时发现了4个鳃组织存在甲基化区域的候选基因。这些盐碱适应候选基因和标记的筛选鉴定为从分子水平解析瓦氏雅罗鱼的耐高碱机制奠定了基础。