人口易位的发生有多种原因,从气候变化导致的流离失所到人为转移。这种行为对遗传变异有不利影响,了解其微观进化后果需要监测。这里,为了监测种群易位的基因组效应,我们回到了褐鳟鱼(Salmotrutta)的实验性释放。1979年,来自两个基因(FST=0.16)和生态上分开的种群的鱼同时被释放,在某个时间点,以前没有褐鳟鱼的湖泊系统。这里,合并DNA的全基因组测序(Pool-seq)用于表征引入种群和居住在释放点下游两个湖泊的鱼类之间的多样性和差异,30年后抽样(C.5代)。目前的结果表明,虽然已经发生了广泛的杂交,两个引入的人口在释放地点下游的湖泊中的代表性不均。一个人口,在生态上居住在其原始栖息地,主要有助于最靠近释放地点的湖泊。其他人口,在其出生栖息地迁徙,在下游的湖中遗传上更多的代表。确定了在新栖息地中进行定向选择的基因组区域,其中,两个已建立种群中的等位基因频率与源于常住人口的引入种群比迁徙种群更相似。结果表明,人口易位的微观进化后果,例如,杂交和适应,可以是快速的,并且Pool-seq可以用作监测全基因组效应的初始工具。
Population translocations occur for a variety of reasons, from displacement due to climate change to human-induced transfers. Such actions have adverse effects on genetic variation and understanding their microevolutionary consequences requires monitoring. Here, we return to an experimental release of brown trout (Salmo trutta) in order to monitor the genomic effects of population translocations. In 1979, fish from each of two genetically (F ST = 0.16) and ecologically separate populations were simultaneously released, at one point in time, to a lake system previously void of brown trout. Here, whole-genome sequencing of pooled DNA (Pool-seq) is used to characterize diversity within and divergence between the introduced populations and fish inhabiting two lakes downstream of the release sites, sampled 30 years later (c. 5 generations). Present results suggest that while extensive hybridization has occurred, the two introduced populations are unequally represented in the lakes downstream of the release sites. One population, which is ecologically resident in its original habitat, mainly contributes to the lake closest to the release site. The other population, migratory in its natal habitat, is genetically more represented in the lake further downstream. Genomic regions putatively under directional selection in the new habitat are identified, where allele frequencies in both established populations are more similar to the introduced population stemming from a resident population than the migratory one. Results suggest that the microevolutionary consequences of population translocations, for example, hybridization and adaptation, can be rapid and that Pool-seq can be used as an initial tool to monitor genome-wide effects.