DIRECTIONAL MUTATION PRESSURE AND NEUTRAL MOLECULAR EVOLUTION
DIRECTIONAL MUTATION PRESSURE AND NEUTRAL MOLECULAR EVOLUTION
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DOI：
10.1073/pnas.85.8.2653
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发表时间：
1988-04-01
影响因子：
11.1
通讯作者：
SUEOKA, N
中科院分区：
文献类型：
--
作者：
SUEOKA, N
1962年提出的定向突变压力定量理论解释了不同细菌之间观察到的DNA碱基组成的广泛差异以及单个细菌物种内的微小异质性。该理论基于这样的假设：突变对基因组的影响不是随机的，而是有方向性的，即DNA中鸟嘌呤加胞嘧啶含量的增加或减少，这种压力在基因组的中性部分比在功能重要的部分产生更多的方向性变化。既然DNA序列数据是可用的，该理论允许估计定向突变压力对选择的中性程度。在分析中使用了新定义的参数，并发现了两个明显的普适常数。DNA序列的分析表明，几乎所有的生物都受到定向突变的压力。该理论还为脊椎动物基因组不同部分之间鸟嘌呤加胞嘧啶含量的巨大异质性提供了合理的解释。
A quantitative theory of directional mutation pressure proposed in 1962 explained the wide variation of DNA base composition observed among different bacteria and its small heterogeneity within individual bacterial species. The theory was based on the assumption that the effect of mutation on a genome is not random but has a directionality toward higher or lower guanine-plus-cytosine content of DNA, and this pressure generates directional changes more in neutral parts of the genome than in functionally significant parts. Now that DNA sequence data are available, the theory allows the estimation of the extent of neutrality of directional mutation pressure against selection. Newly defined parameters were used in the analysis, and two apparrently universal constants were discovered. Analysis of DNA sequence has revealed that practically all organisms are subject to directional mutation pressure. The theroy also offers plausible explanations for the large heterogeneity in guanine-plus-cytosine content among different parts of the vertebrate genome.