Coevolution of Interacting Fertilization Proteins
Coevolution of Interacting Fertilization Proteins
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DOI：
10.1371/journal.pgen.1000570
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发表时间：
2009-07-01
期刊：
影响因子：
4.5
通讯作者：
Swanson, Willie J.
中科院分区：
文献类型：
--
作者：
Clark, Nathaniel L.;Gasper, Joe;Swanson, Willie J.
生殖蛋白是蛋白质组中进化最快的蛋白质之一，这通常是由于正选择的结果，它们的快速进化通常归因于相互作用的雌性和雄性蛋白质之间的共同进化过程。这样的过程可能会在共同进化的基因上留下特征性的标记。性选择理论预测的共同进化的一个标志是两个基因之间等位基因的关联。另一个预测的签名是由于补偿性进化而导致的分化过程中进化速率的相关性。我们研究了雌性-雄性共同进化的鲍鱼精子溶素和其相互作用的卵外壳蛋白，VERL，在两个物种的人口。正如预测的那样，我们发现溶素和VERL之间的基因间连锁不平衡，尽管我们证明它们没有物理联系。这一发现支持了使用实际基因型进行性选择的中心预测，即男性特征与其女性偏好位点之间的关联。我们还创建了一种新的似然方法，表明溶素和VERL经历了相关的进化速率。这两个共同进化的签名可以提供统计学上的严谨性的共同进化的假设，并可以利用识别共同进化的蛋白质的先验。我们还提出了基于多态性的证据，积极的选择和牵连最近的选择性事件在特定的结构区域的溶素和VERL负责其物种特异性的相互作用。最后，我们在一个物种中观察到VERL等位基因之间的深度细分，这与性冲突的理论预测相匹配。因此，鲍鱼受精蛋白说明了共同进化如何导致生殖障碍，并可能推动物种形成。
Reproductive proteins are among the fastest evolving in the proteome, often due to the consequences of positive selection, and their rapid evolution is frequently attributed to a coevolutionary process between interacting female and male proteins. Such a process could leave characteristic signatures at coevolving genes. One signature of coevolution, predicted by sexual selection theory, is an association of alleles between the two genes. Another predicted signature is a correlation of evolutionary rates during divergence due to compensatory evolution. We studied female-male coevolution in the abalone by resequencing sperm lysin and its interacting egg coat protein, VERL, in populations of two species. As predicted, we found intergenic linkage disequilibrium between lysin and VERL, despite our demonstration that they are not physically linked. This finding supports a central prediction of sexual selection using actual genotypes, that of an association between a male trait and its female preference locus. We also created a novel likelihood method to show that lysin and VERL have experienced correlated rates of evolution. These two signatures of coevolution can provide statistical rigor to hypotheses of coevolution and could be exploited for identifying coevolving proteins a priori. We also present polymorphism-based evidence for positive selection and implicate recent selective events at the specific structural regions of lysin and VERL responsible for their species-specific interaction. Finally, we observed deep subdivision between VERL alleles in one species, which matches a theoretical prediction of sexual conflict. Thus, abalone fertilization proteins illustrate how coevolution can lead to reproductive barriers and potentially drive speciation.