School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK.
NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.
Sci Rep. 2020 Nov 26;10(1):20725. doi: 10.1038/s41598-020-77517-w.
When and where animals breed can shape the genetic structure and diversity of animal populations. The importance of drivers of genetic diversity is amplified in island populations that tend to have more delineated gene pools compared to continental populations. Studies of relatedness as a function of the spatial distribution of individuals have demonstrated the importance of spatial organisation for individual fitness with outcomes that are conditional on the overall genetic diversity of the population. However, few studies have investigated the impact of breeding timing on genetic structure. We characterise the fine-scale genetic structure of a geographically-isolated population of seabirds. Microsatellite markers provide evidence for largely transient within-breeding season temporal processes and limited spatial processes, affecting genetic structure in an otherwise panmictic population of sooty terns Onychoprion fuscatus. Earliest breeders had significantly different genetic structure from the latest breeders. Limited evidence was found for localised spatial structure, with a small number of individuals being more related to their nearest neighbours than the rest of the population. Therefore, population genetic structure is shaped by heterogeneities in collective movement in time and to a lesser extent space, that result in low levels of spatio-temporal genetic structure and the maintenance of genetic diversity.
动物的繁殖时间和地点会影响动物种群的遗传结构和多样性。与大陆种群相比，岛屿种群的基因库往往更为明确，因此遗传多样性的驱动因素更为重要。研究个体空间分布与亲缘关系之间的关系表明，个体的空间组织对个体适应性具有重要意义，其结果取决于种群的整体遗传多样性。然而，很少有研究调查繁殖时间对遗传结构的影响。我们描述了一种地理位置孤立的海鸟种群的精细遗传结构。微卫星标记提供了大量证据，证明在繁殖季节内存在短暂的时空过程，以及有限的空间过程，这些过程影响了 otherwise panmictic（遗传上混合的）的乌燕鸥群体的遗传结构。最早繁殖的个体与最晚繁殖的个体具有显著不同的遗传结构。局部空间结构的证据有限，少数个体与最近的邻居的亲缘关系比与其他个体的亲缘关系更密切。因此，种群遗传结构是由集体在时间和空间上的异质性所塑造的，这种异质性导致了低水平的时空遗传结构和遗传多样性的维持。
