Data from: Stocking impacts the expression of candidate genes and physiological condition in introgressed brook charr (Salvelinus fontinalis) populations

Translocation of plants and animal populations between environments is one of the major forms of anthropogenic perturbation experienced by pristine populations, and consequently, human mediated hybridization by stocking practices between wild and exogenous conspecifics is of increasing concern. In this study, we compared the expression of seven candidate genes involved in multifactorial traits and regulatory pathways for growth as a function of level of introgressive hybridization between wild and domestic brook charr to test the null hypothesis of no effect of introgression on wild fish. Our analyses revealed that the expression of two of the genes tested, cytochrome c oxidase VIIa and the growth hormone receptor isoform I, was positively correlated with the level of introgression. We also observed a positive relationship between the extent of introgression and physiological status quantified by the Fulton’s condition index. The expression of other genes was influenced by other variables, including year of sampling (reflecting different thermal conditions), sampling method and lake of origin. This is the first demonstration in nature that introgression from stocked populations has an impact on the expression of genes playing a role in important biological functions that may be related with fitness in wild introgressed populations.动植物种群跨生境移殖，是原始未受干扰种群所面临的主要人为干扰类型之一；由此引发的、通过放养实践实现的野生种群与外来同种种群间的人类介导杂交，也日益受到学界关注。本研究选取7个与多因子性状及生长调控通路相关的候选基因，以野生与家养溪红点鲑的渐渗杂交水平为变量，比较其基因表达量，以此检验“渐渗对野生鱼类无影响”的零假设。分析结果显示，本次检测的7个基因中，细胞色素C氧化酶VIIa（cytochrome c oxidase VIIa）与生长激素受体亚型I（growth hormone receptor isoform I）的表达量与渐渗水平呈正相关。本研究同时发现，渐渗程度与通过富尔顿健康指数（Fulton’s condition index）量化的生理状态之间同样存在正相关关系。其余基因的表达量则受其他变量影响，包括采样年份（反映不同水温条件）、采样方法以及起源湖泊。本研究首次在自然种群中证实，放养种群的渐渗作用，会对野生渐渗种群中参与重要生物学功能（可能与进化适合度相关）的基因表达产生影响。