Data from: Standing genetic diversity and selection at functional gene loci are associated with differential invasion success in two non-native fish species

Invasive species are expected to experience a unique combination of high genetic drift due to demographic factors while also experiencing strong selective pressures. The paradigm that reduced genetic diversity should limit the evolutionary potential of invasive species and thus their potential for range expansion has received little empirical support, possibly due to the choice of genetic markers. Our goal was to test for effects of genetic drift and selection at functional genetic markers as they relate to the invasion success of two paired invasive goby species, one widespread (successful) and one with limited range expansion (less successful). We genotyped fish using two marker types: single nucleotide polymorphisms (SNPs) in known-function, protein-coding genes and microsatellites to contrast the effects of neutral genetic processes. We identified reduced allelic variation in the invaded range for the less-successful tubenose goby. SNPs putatively under selection were responsible for the observed differences in population structure between marker types for round goby (successful) but not tubenose goby (less successful). A higher proportion of functional loci experienced divergent selection for round goby, suggesting increased evolutionary potential in invaded ranges may be associated with round goby's greater invasion success. Genes involved in thermal tolerance were divergent for round goby populations but not tubenose goby, consistent with the hypothesis that invasion success for fish in temperate regions is influenced by capacity for thermal tolerance. Our results highlight the need to incorporate functional genetic markers in studies to better assess evolutionary potential for the improved conservation and management of species.

入侵物种往往会经历由种群统计因子驱动的高强度遗传漂变，同时面临强烈的选择压力。此前广为接受的"遗传多样性降低会限制入侵物种的进化潜力，进而制约其分布范围扩张"的范式，却鲜有实证支持，这一现象可能与研究选用的遗传标记类型有关。
本研究旨在探究功能型遗传标记（functional genetic markers）下的遗传漂变与选择效应，及其与两种配对入侵虾虎鱼物种入侵成功性的关联：一种为广布型（入侵成功）的圆头虾虎鱼（round goby），另一种为范围扩张受限型（入侵较不成功）的管鼻虾虎鱼（tubenose goby）。我们采用两种标记类型对受试鱼类进行基因分型：一是已知功能的蛋白编码基因中的单核苷酸多态性（SNPs），二是微卫星标记（microsatellites），以对比中性遗传过程的影响。
研究发现，入侵范围种群的等位基因变异在较不成功的管鼻虾虎鱼中出现显著降低。对于入侵成功的圆头虾虎鱼，推定受选择的SNPs是造成不同标记类型间种群结构差异的原因，但在较不成功的管鼻虾虎鱼中未观察到此现象。圆头虾虎鱼中经历歧化选择的功能位点比例更高，这表明入侵范围种群的进化潜力提升可能与其更强的入侵成功性相关。与耐热性相关的基因在圆头虾虎鱼种群中出现了歧化选择，而管鼻虾虎鱼种群则未出现此现象，这与"温带地区鱼类的入侵成功性受耐热能力影响"的假说一致。
本研究结果强调，在相关研究中纳入功能型遗传标记，有助于更准确地评估进化潜力，从而为物种保护与管理提供更科学的依据。