Data from: Temporal stability of genetic variability and differentiation in the three-spined stickleback (Gasterosteus aculeatus)

Temporal variation in allele frequencies, whether caused by deterministic or stochastic forces, can inform us about interesting demographic and evolutionary phenomena occurring in wild populations. In spite of the continued surge of interest in the genetics of three-spined stickleback (Gasterosteus aculeatus) populations, little attention has been paid towards the temporal stability of allele frequency distributions, and whether there are consistent differences in effective size (Ne) of local populations. We investigated temporal stability of genetic variability and differentiation in 15 microsatellite loci within and among eight collection sites of varying habitat type, surveyed twice over a six-year time period. In addition, Nes were estimated with the expectation that they would be lowest in isolated ponds, intermediate in larger lakes and largest in open marine sites. In spite of the marked differences in genetic variability and differentiation among the study sites, the temporal differences in allele frequencies, as well as measures of genetic diversity and differentiation, were negligible. Accordingly, the Ne estimates were temporally stable, but tended to be lower in ponds than in lake or marine habitats. Hence, we conclude that allele frequencies in putatively neutral markers in three-spined sticklebacks seem to be temporally stable – at least over periods of few generations – across a wide range of habitat types differing markedly in levels of genetic variability, effective population size and gene flow.

等位基因频率的时间变化，无论由确定性因素（deterministic forces）还是随机性因素（stochastic forces）驱动，均可为我们揭示野生种群中发生的各类有趣的种群动态与进化现象。尽管学界对三刺鱼（Gasterosteus aculeatus，three-spined stickleback）种群的遗传学研究热情持续高涨，但针对等位基因频率分布的时间稳定性，以及当地种群有效种群大小（effective size, Ne）是否存在一致差异的相关研究却相对匮乏。本研究针对8个不同生境类型的采样点内部及相互间的15个微卫星位点（microsatellite loci），在6年的时间跨度内开展了两次采样，以探究遗传变异与遗传分化的时间稳定性。此外，我们还对有效种群大小进行了估算，预期其数值在孤立池塘中最低，大型湖泊中居中，开放海洋生境中最高。尽管各研究站点间的遗传变异与遗传分化存在显著差异，但等位基因频率的时间差异，以及遗传多样性与遗传分化的各项衡量指标，均可忽略不计。据此，有效种群大小的估算值在时间维度上保持稳定，但池塘生境中的估算值普遍低于湖泊或海洋生境。综上，我们得出结论：三刺鱼体内推定中性标记（putatively neutral markers）的等位基因频率，在遗传变异水平、有效种群大小与基因流（gene flow）水平均存在显著差异的各类生境中，至少在数代的时间尺度内，均表现出时间稳定性。