SPECIATION IN THE EUROPEAN RABBIT (ORYCTOLAGUS CUNICULUS): ISLANDS OF DIFFERENTIATION ON THE X CHROMOSOME AND AUTOSOMES
SPECIATION IN THE EUROPEAN RABBIT (ORYCTOLAGUS CUNICULUS): ISLANDS OF DIFFERENTIATION ON THE X CHROMOSOME AND AUTOSOMES
复制标题
DOI：
10.1111/j.1558-5646.2010.01092.x
复制
发表时间：
2010-12-01
期刊：
影响因子：
3.3
通讯作者：
Nachman, Michael W.
中科院分区：
文献类型：
--
作者：
Carneiro, Miguel;Blanco-Aguiar, Jose A.;Nachman, Michael W.
研究密切相关的类群之间的基因流可以提供深入了解物种形成的遗传基础。为了评价X染色体在欧洲兔亚种间生殖隔离中的重要性，并研究分化岛延伸的基因组规模，我们对沿着X染色体和14号染色体分布的34个位点进行了重测序。以前的研究基于一些标记表明，在兔亚种之间的着丝粒区域的基因座高度分化，而在端粒区域的基因座分化较小。在这里，我们证实了这一发现，但也发现了基因座之间的分化水平的显着变化，F-ST值从近0到1。使用隔离与迁移模型的分析表明，这一范围似乎在很大程度上是由不同水平的基因座之间的基因流解释。X染色体比常染色体分化更明显。在14号染色体上，随着距离着丝粒的距离增加，分化衰减得非常快，但在X染色体上，在着丝粒区域和沿着染色体臂都观察到包含几个兆碱基的分化岛。这些发现支持了X染色体在兔亚种间生殖隔离中起重要作用的观点。这些结果也证明了物种边界基因组的镶嵌性质。
Studies of gene flow between closely related taxa can provide insight into the genetic basis of speciation. To evaluate the importance of the X chromosome in reproductive isolation between subspecies of the European rabbit and to study the genomic scale over which islands of differentiation extend, we resequenced a total of 34 loci distributed along the X chromosome and chromosome 14. Previous studies based on few markers suggested that loci in centromeric regions were highly differentiated between rabbit subspecies, whereas loci in telomeric regions were less differentiated. Here, we confirmed this finding but also discovered remarkable variation in levels of differentiation among loci, with F-ST values from nearly 0 to 1. Analyses using isolation-with-migration models suggest that this range appears to be largely explained by differential levels of gene flow among loci. The X chromosome was significantly more differentiated than the autosomes. On chromosome 14, differentiation decayed very rapidly at increasing distances from the centromere, but on the X chromosome distinct islands of differentiation encompassing several megabases were observed both at the centromeric region and along the chromosome arms. These findings support the idea that the X chromosome plays an important role in reproductive isolation between rabbit subspecies. These results also demonstrate the mosaic nature of the genome at species boundaries.