Laboratoire Ecologie, Systématique et Evolution, UMR8079, CNRS, Univ Paris-Sud 11, Orsay, France.
Heredity (Edinb). 2012 Oct;109(4):204-14. doi: 10.1038/hdy.2012.30. Epub 2012 Jun 6.
Reproductive isolation is an essential ingredient of speciation, and much has been learned in recent years about the evolution of reproductive isolation and the genetics of reproductive barriers in animals and plants. Fungi have been neglected on these aspects, despite being tractable model eukaryotes. Here, we used a model fitting approach to look at the importance of different barriers to gene flow to explain the decrease of reproductive compatibility with genetic distance in fungi. We found support for the occurrence of reinforcement in the presyngamy compatibility among basidiomycetes. In contrast, no evidence for reinforcement was detected in ascomycetes, concurring with the idea that host/habitat adaptation in this group can pleiotropically cause reproductive isolation. We found no evidence of a snowballing accumulation of postsyngamic reproductive incompatibilities in either ascomycetes or the complex of anther smut fungi. Together with previous studies, our results suggest that ecologically based barriers to gene flow and karyotypic differences may have an important role in hybrid inviability and sterility in fungi. Interestingly, hybrid sterility appeared to evolve faster than hybrid inviability in fungi.
生殖隔离是物种形成的重要组成部分，近年来，人们对动物和植物生殖隔离的进化以及生殖障碍的遗传学有了更多的了解。尽管真菌是可研究的模式真核生物，但在这些方面却被忽视了。在这里，我们使用模型拟合方法来研究不同的基因流障碍对解释真菌中生殖相容性随遗传距离下降的重要性。我们发现支持在担子菌的合子前相容性中存在强化作用。相比之下，在子囊菌中没有发现强化的证据，这与宿主/栖息地适应在该组中可以多效性地导致生殖隔离的观点一致。我们没有发现子囊菌或花药黑粉菌复合体中合子后生殖不相容性的雪球式积累的证据。与之前的研究一起，我们的结果表明，基于生态的基因流障碍和染色体差异可能在真菌的杂种不育和杂种不育中起重要作用。有趣的是，真菌中的杂种不育似乎比杂种不育进化得更快。
