Human SNPs reveal no evidence of frequent positive selection
Human SNPs reveal no evidence of frequent positive selection
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DOI：
10.1093/molbev/msi240
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发表时间：
2005-12-01
影响因子：
10.7
通讯作者：
Li, WH
中科院分区：
文献类型：
--
作者：
Zhang, LQ;Li, WH
我们比较了人类182个管家基因和148个组织特异性基因的单核苷酸多态性（SNP）。SNP根据其频率分为罕见多态性和常见多态性。我们发现，管家基因往往比组织特异性基因的罕见和常见的单核苷酸多态性少。使用小鼠作为计算序列分歧的第二物种，我们没有发现正选择的证据：对于管家基因和组织特异性基因，每个位点的非同义与同义共同SNP的比率与分歧没有显着差异。同样，我们没有观察到289和149个基因的正选择的证据，这些基因分别具有可用于人类和黑猩猩之间以及人类和旧世界猴之间的分歧计算的直系同源物。与以前的SNP研究的比较表明，在人类群体中，近似20%的非同义SNP几乎是中性的，人类基因组中的正选择可能不像以前认为的那样频繁。
We compared the single-nucleotide polymorphisms (SNPs) in humans in 182 housekeeping and 148 tissue-specific genes. SNPs were divided into rare and common polymorphisms based on their frequencies. We found that housekeeping genes tend to be less polymorphic than tissue-specific genes for both rare and common SNPs. Using mouse as a second species for computing sequence divergences, we found no evidence of positive selection: for both housekeeping and tissue-specific genes, the ratio of nonsynonymous to synonymous common SNPs per site showedd no significant difference from that of divergence. Similarly, we observed no evidence of positive selection for the 289 and 149 genes that have orthologs available for divergence calculation between humans and chimpanzees and between humans and Old World monkeys, respectively. A comparison with previous SNP studies suggests that similar to 20% of the nonsynonymous SNPs in the human population are nearly neutral and that positive selection in the human genome might not be as frequent as previously thought.