人类和黑猩猩染色体同义和非同义替代的非平行累积(英文)

Nonparallel accumulation of synonymous and non-synonymous substitutions on human and chimpanzee chromosomes

为了揭示灵长类染色体的进化动态,以小鼠和狗作为外群,使用比较基因组学和生物信息学的方法,详细分析了人-小鼠、人-狗、黑猩猩-小鼠、黑猩猩-狗中的16427,15161,15802和14559同源基因.结果表明,人类和黑猩猩染色体16,19,21和22上的基因具有显著高的同义替代速率(dS).分析人类-小鼠-狗和黑猩猩-小鼠-狗的同源基因,发现不同系谱基因碱基的同义和非同义替代速率(dN)是相似的,揭示了这些物种基因的碱基替代速率经历着相似的进化选择压力.此外,结果也表明局部染色质环境(GC含量和基因密度)和染色体重组速率对人类染色体碱基替代的累积也有显著影响.

To reveal the evolutionary dynamics of primate chromosomes,using mice and dogs as backgrounds,we analyzed a total of 61949 pairs of genes by comparative genomics and bioinformatics methods,which included 16 427,15 161,15 802and 14 559ortholog pairs identified,from human-mouse,human-dog,chimpanzee-mouse and chimpanzee-dog phylogenies respectively.The results show that,in humans and chimpanzees,genes on chromosomes 16,19,21and 22have featured significantly higher synonymous substitution rates（dS）.Analysis of human-mouse-dog and chimpanzee-mouse-dog ortholog trios also indicates dS and non- synonymous substitution rates（dN）to be homogeneous across different phylogeny branches,suggesting that the relevant genes have been subjected to similar selection for base substitution rates.The analysis also suggests that local chromatin environment,such as GC content and gene density,may contribute to the accumulation of both types of substitutions on human chromosomes.Furthermore,recombination rates seem to have a significant influence on the dSof human chromosomes.