Data from: The strength of the association between heterozygosity and probability of interannual local recruitment increases with environmental harshness in blue tits

The extent of inbreeding depression and the magnitude of heterozygosity–fitness correlations (HFC) have been suggested to depend on the environmental context in which they are assayed, but little evidence is available for wild populations. We combine extensive molecular and capture–mark–recapture data from a blue tit (Cyanistes caeruleus) population to (1) analyze the relationship between heterozygosity and probability of interannual adult local recruitment and (2) test whether environmental stress imposed by physiologically suboptimal temperatures and rainfall influence the magnitude of HFC. To address these questions, we used two different arrays of microsatellite markers: 14 loci classified as neutral and 12 loci classified as putatively functional. We found significant relationships between heterozygosity and probability of interannual local recruitment that were most likely explained by variation in genomewide heterozygosity. The strength of the association between heterozygosity and probability of interannual local recruitment was positively associated with annual accumulated precipitation. Annual mean heterozygosity increased over time, which may have resulted from an overall positive selection on heterozygosity over the course of the study period. Finally, neutral and putatively functional loci showed similar trends, but the former had stronger effect sizes and seemed to better reflect genomewide heterozygosity. Overall, our results show that HFC can be context dependent, emphasizing the need to consider the role of environmental heterogeneity as a key factor when exploring the consequences of individual genetic diversity on fitness in natural populations.

近交衰退的程度与杂合度-适合度相关性（heterozygosity–fitness correlations, HFC）的强度，此前被认为取决于其测定所处的环境背景，但针对野生种群的相关证据仍较为匮乏。我们结合了某青山雀（Cyanistes caeruleus）种群的大规模分子数据与标记-重捕数据，旨在（1）分析杂合度与成年个体年际本地留存概率之间的关联；（2）检验由生理不适温度与降雨所施加的环境压力，是否会影响HFC的强度。为解答上述问题，我们使用了两套不同的微卫星标记阵列：14个中性位点与12个推定功能位点。研究发现，杂合度与成年个体年际本地留存概率之间存在显著关联，该关联大概率可由基因组-wide杂合度（genomewide heterozygosity）的变异所解释。杂合度与成年个体年际本地留存概率之间的关联强度，与年累积降水量呈正相关。研究期间种群的年平均杂合度随时间推移有所上升，这可能源于整个研究周期内对杂合度的整体正向选择。最后，中性位点与推定功能位点展现出相似的变化趋势，但前者的效应量更大，且似乎能更好地反映基因组-wide杂合度。总体而言，我们的研究结果表明HFC的强度可能依赖于环境背景，这凸显了在探索自然种群中个体遗传多样性对适合度的影响时，需将环境异质性作为关键因素纳入考量。