Testing the chromosomal speciation hypothesis for humans and chimpanzees.
Testing the chromosomal speciation hypothesis for humans and chimpanzees.
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测试人类和黑猩猩的染色体物种形成假说。
DOI：
10.1101/gr.1891104
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发表时间：
2004
期刊：
影响因子：
7
通讯作者：
Podlaha,Ondrej
中科院分区：
文献类型：
--
作者：
Zhang,Jianzhi;Wang,Xiaoxia;Podlaha,Ondrej
隔离种群之间染色体重排的固定差异可能会通过阻止二次接触时种群间的基因流动来促进物种形成，要么是因为杂交后代的适合度降低，要么更有可能是因为重新排列的染色体区域的重组减少了。因此，这一染色体物种形成假说预测，重排染色体的遗传分化比共线染色体更快，因为前者对基因流动的渗透性较小。许多对真菌、植物和动物的研究，包括有限的人类和黑猩猩的遗传数据，都支持这一假说。在这里，我们用比以前使用的更多的基因组数据重新检验了对人类和黑猩猩的假设。在物种间基因组DNA序列差异水平上，重排染色体和共线染色体之间没有差异。蛋白质序列也是如此。当大猩猩被用作外群时，没有发现与染色体重排相关的蛋白质序列进化的加速。此外，在重排和共线染色体中，同源基因之间的表达模式差异并不显著。这些结果表明，染色体重排不会影响人类和黑猩猩之间的遗传分化速度，如果区分人类和黑猩猩的进化谱系上的早期物种没有杂交，那么这些结果是可以预料的。
Fixed differences of chromosomal rearrangements between isolated populations may promote speciation by preventing between-population gene flow upon secondary contact, either because hybrids suffer from lowered fitness or, more likely, because recombination is reduced in rearranged chromosomal regions. This chromosomal speciation hypothesis thus predicts more rapid genetic divergence on rearranged than on colinear chromosomes because the former are less porous to gene flow. A number of studies of fungi, plants, and animals, including limited genetic data of humans and chimpanzees, support the hypothesis. Here we reexamine the hypothesis for humans and chimpanzees with substantially more genomic data than were used previously. No difference is observed between rearranged and colinear chromosomes in the level of genomic DNA sequence divergence between species. The same is also true for protein sequences. When the gorilla is used as an outgroup, no acceleration in protein sequence evolution associated with chromosomal rearrangements is found. Furthermore, divergence in expression pattern between orthologous genes is not significantly different for rearranged and colinear chromosomes. These results, showing that chromosomal rearrangements did not affect the rate of genetic divergence between humans and chimpanzees, are expected if incipient species on the evolutionary lineages separating humans and chimpanzees did not hybridize.