Cloning and Selfing Affect Population Genetic Variation in Simulations of Outcrossing, Sexual Sea Stars
Cloning and Selfing Affect Population Genetic Variation in Simulations of Outcrossing, Sexual Sea Stars
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DOI：
10.1086/717293
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发表时间：
2021-12-01
影响因子：
1.6
通讯作者：
Byrne，Maria
中科院分区：
文献类型：
--
作者：
Hart，Michael W.;Guerra，Vanessa I.;Byrne，Maria
许多海星在成虫和幼虫的生命周期阶段都以兼性或专性无性繁殖而闻名。一些物种和谱系也能进行兼性或专性雌雄同体生殖和自交受精。然而，群体遗传变异模型和遗传数据的实证分析通常只假设有性繁殖和异交。最近对一种最著名的海星（棘冠海星；棘星）的两项研究中先前发表的经验数据（微卫星基因型）的重新分析得出结论，该物种的克隆和自交受精非常罕见，对种群遗传变异的模式贡献很小。本文通过在一系列海星人口统计学模型中模拟克隆和自交对遗传变异的贡献来重新考虑这一结论。在两个简单模型中模拟的变异（类似于先前对经验数据的分析）与高克隆率或自交率或两者兼而有之一致。描述具有生态意义的海星种群流动特征的更现实的情景，包括破坏珊瑚礁的棘冠海星的爆发、amurensis的入侵以及杀死pisaster ochraceus的海星损耗病的兽疫，也显示了克隆和自繁殖对亚种群内部变异和亚种群之间分化的显著但较小的影响。在类似的研究系统中，未来的遗传变异模型或分析可能受益于模拟建模，以描述克隆或自交对种群样本中遗传变异的可能贡献，或了解在推断克隆或自交对自然界的影响方面的限制。
Many sea stars are well known for facultative or obligate asexual reproduction in both the adult and larval life-cycle stages. Some species and lineages are also capable of facultative or obligate hermaphroditic reproduction with self-fertilization. However, models of population genetic variation and empirical analyses of genetic data typically assume only sexual reproduction and outcrossing. A recent reanalysis of previously published empirical data (microsatellite genotypes) from two studies of one of the most well-known sea star species (the crown-of-thorns sea star;Acanthastersp.) concluded that cloning and self-fertilization in that species are rare and contribute little to patterns of population genetic variation. Here we reconsider that conclusion by simulating the contribution of cloning and selfing to genetic variation in a series of models of sea star demography. Simulated variation in two simple models (analogous to previous analyses of empirical data) was consistent with high rates of cloning or selfing or both. More realistic scenarios that characterize population flux in sea stars of ecological significance, including outbreaks of crown-of-thorns sea stars that devastate coral reefs, invasions byAsterias amurensis, and epizootics of sea star wasting disease that killPisaster ochraceus, also showed significant but smaller effects of cloning and selfing on variation within subpopulations and differentiation between subpopulations. Future models or analyses of genetic variation in similar study systems might benefit from simulation modeling to characterize possible contributions of cloning or selfing to genetic variation in population samples or to understand the limits on inferring the effects of cloning or selfing in nature.