Dynamic Cohort Analysis Reveals Fluctuating Patterns of Selection Within a Hybrid Zone Between the Killifish Fundulus heteroclitus and F. grandis
Dynamic Cohort Analysis Reveals Fluctuating Patterns of Selection Within a Hybrid Zone Between the Killifish Fundulus heteroclitus and F. grandis
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DOI：
10.1007/s11692-021-09553-x
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发表时间：
2021-10
影响因子：
2.5
通讯作者：
M. Gilg;Emily V. Kerns;Natalia E Gutierrez-Bayona;Catherine Kooyomjian;N. A. Hinojosa
中科院分区：
文献类型：
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作者：
M. Gilg;Emily V. Kerns;Natalia E Gutierrez-Bayona;Catherine Kooyomjian;N. A. Hinojosa
混合区为研究最近分化的类群之间的物种形成过程和生态相互作用提供了绝佳的机会。历史上，杂交区被分为两类：杂交区的适应度与环境无关；以及环境因素影响不同基因型的适应度的区。本研究调查了鳉鱼Fundulusheteroclitus和F.Fundulusheteroclitus之间杂交区内某个位置的时间遗传模式。 grandis，旨在确定杂交的程度和方向性以及不同基因型的适应性。将三年内收集的鱼类分为两个年龄组，并在物种之间高度分化的三个核位点和一个线粒体位点进行基因分型，从而可以比较同一群体的不同年龄组之间的遗传模式。杂交后代的个体在研究地点很普遍，其中大多数可能是高代杂交种或与亲本类群之一的回交。队列分析显示，在一些队列中，但不是所有队列中，单基因座和双位点杂交基因型的丰度均减少，等位基因频率随着年龄的增加而发生方向性变化。研究过程中这些波动的选择模式表明，健康可能受到环境因素的强烈影响。
Hybrid zones provide excellent opportunities to study speciation processes and ecological interactions between recently diverged taxa. Historically, hybrid zones have been divided into those in which fitness of hybrids is independent of the environment, and those in which environmental factors influence the fitness of different genotypes. The present study investigated the temporal genetic patterns at a location within a hybrid zone between the killifishFundulus heteroclitusandF. grandis, in an effort to determine the extent and directionality of hybridization and the fitness of different genotypes. Fishes collected over the course of three years were placed into two age classes and genotyped at three nuclear loci and one mitochondrial locus that are highly differentiated between the species, allowing for comparison of genetic patterns between different age classes of the same cohorts. Individuals of hybrid descent were prevalent at the study site, the majority of which were likely advanced generation hybrids or backcrosses to one of the parental taxa. The cohort analyses revealed decreased abundance of both single and dilocus hybrid genotypes, and directional changes in allele frequency with increased age in some, but not all cohorts. These fluctuating patterns of selection across the course of the study suggest that fitness is likely strongly influenced by environmental factors.