Kodama Miyako, Naish Kerry A, Devlin Robert H
Fisheries and Oceans Canada West Vancouver British Columbia Canada.
School of Aquatic and Fishery Sciences University of Washington Seattle, Washington.
Evol Appl. 2018 Oct 16;11(10):1886-1900. doi: 10.1111/eva.12692. eCollection 2018 Dec.
Genetic engineering has been increasingly applied to many commercially important plant and animal species, generating phenotypic changes that are not observed in natural populations and creating genetic interactions that have not experienced natural selection. The degree to and way in which such human-induced genetic variation interacts with the rest of the genome is currently largely unknown. Integrating such information into ecological and risk assessment frameworks is crucial to understand the potential effects of genetically modified organisms in natural environments. Here, we performed QTL mapping to investigate the genetic architecture of growth-related traits in nontransgenic (NT) and growth hormone transgenic (T) coho salmon with large changes in growth and related physiology, with the aim of identifying how an inserted transgene might influence the opportunity for selection. These fish shared the same parental genetic background, thus allowing us to determine whether the same or different loci influence these traits within the two groups. The use of over 1,700 loci, derived from restriction site-associated DNA sequencing, revealed that different genomic regions were linked with growth over time between the two groups. Additionally, the effect sizes of detected QTL appear to have been influenced by the transgene. Direct comparison of QTL between the T and NT fish during two size-matched periods identified little overlap in their location. Taken together, the results showed that the transgene altered the genetic basis of growth-related traits in this species. The study has important implications for effective conservation and management of wild populations experiencing introduction of transgenes. Evolutionary changes and their ecological consequences may occur at different rates and in different directions in NT versus T individuals in response to selection. Thus, assessments of phenotypic change, and hence ecological risk, should be determined periodically to evaluate whether initial estimates made with founder strains remain valid.
基因工程已越来越多地应用于许多具有重要商业价值的动植物物种，产生了自然种群中未观察到的表型变化，并创造了未曾经历自然选择的基因相互作用。目前，这种人为诱导的基因变异与基因组其他部分相互作用的程度和方式在很大程度上尚不清楚。将此类信息整合到生态和风险评估框架中，对于理解转基因生物在自然环境中的潜在影响至关重要。在此，我们进行了数量性状基因座（QTL）定位，以研究生长和相关生理发生巨大变化的非转基因（NT）和生长激素转基因（T）银大麻哈鱼生长相关性状的遗传结构，目的是确定插入的转基因如何影响选择机会。这些鱼具有相同的亲本遗传背景，从而使我们能够确定两组中相同或不同的基因座是否影响这些性状。使用来自限制性位点相关DNA测序的1700多个基因座，结果表明两组之间不同的基因组区域与随时间的生长相关。此外，检测到的QTL的效应大小似乎受到转基因的影响。在两个大小匹配时期对T鱼和NT鱼的QTL进行直接比较，发现它们的位置几乎没有重叠。综合来看，结果表明转基因改变了该物种生长相关性状的遗传基础。该研究对于有效保护和管理经历转基因引入的野生种群具有重要意义。在NT个体与T个体中，进化变化及其生态后果可能因选择而以不同速率和不同方向发生。因此，应定期确定表型变化评估以及生态风险评估，以评估用奠基菌株做出的初始估计是否仍然有效。
