Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and the History of Art, University of Oxford, Oxford OX1 3QY, UK.
Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843, USA.
Proc Biol Sci. 2020 Jun 10;287(1928):20200690. doi: 10.1098/rspb.2020.0690. Epub 2020 Jun 3.
Numerous pairs of evolutionarily divergent mammalian species have been shown to produce hybrid offspring. In some cases, F hybrids are able to produce Fs through matings with Fs. In other instances, the hybrids are only able to produce offspring themselves through backcrosses with a parent species owing to unisexual sterility (Haldane's Rule). Here, we explicitly tested whether genetic distance, computed from mitochondrial and nuclear genes, can be used as a proxy to predict the relative fertility of the hybrid offspring resulting from matings between species of terrestrial mammals. We assessed the proxy's predictive power using a well-characterized felid hybrid system, and applied it to modern and ancient hominins. Our results revealed a small overlap in mitochondrial genetic distance values that distinguish species pairs whose calculated distances fall within two categories: those whose hybrid offspring follow Haldane's Rule, and those whose hybrid F offspring can produce Fs. The strong correlation between genetic distance and hybrid fertility demonstrated here suggests that this proxy can be employed to predict whether the hybrid offspring of two mammalian species will follow Haldane's Rule.
已经有许多对进化上不同的哺乳动物物种被证明能产生杂交后代。在某些情况下，F1 杂种能够通过与 F1 杂种的交配产生 F2。在其他情况下，由于单性不育（哈代规则），杂种只能通过与亲本物种的回交来产生后代。在这里，我们明确测试了从线粒体和核基因计算得出的遗传距离是否可以作为预测由陆地哺乳动物物种之间交配产生的杂交后代相对生育能力的替代物。我们使用一个特征良好的猫科动物杂交系统评估了替代物的预测能力，并将其应用于现代和古代人类。我们的结果显示，线粒体遗传距离值的小重叠区分了那些杂交后代遵循哈代规则的物种对，以及那些杂交 F1 后代能够产生 F2 的物种对。这里显示的遗传距离与杂交育性之间的强相关性表明，该替代物可用于预测两个哺乳动物物种的杂交后代是否遵循哈代规则。
