Testing a covariotide model of DNA substitution
Testing a covariotide model of DNA substitution
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DOI：
10.1093/oxfordjournals.molbev.a004128
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发表时间：
2002-05-01
影响因子：
10.7
通讯作者：
Huelsenbeck, JP
中科院分区：
文献类型：
--
作者：
Huelsenbeck, JP
DNA 替换的伴随可变密码子假说认为，在任何时候，基因中只有一小部分密码子能够接受突变。然而，由于突变固定在基因中的某些位置，因此潜在可变的位点也会因功能限制的变化而发生变化。该假设被称为“协变”假说，或者当该模型应用于核苷酸时，被称为“协变肽”假说。协变-协变肽模型已被证明非常难以测试。在这里，我使用似然比检验检查 I I 基因的协变量假设。我表明，在检查的九个基因中，协变量模型比不允许约束随时间变化的模型提供了更好的数据解释。
The concomitantly variable codons hypothesis of DNA substitution argues that at any time only a fraction of the codons in a gene are capable of accepting a mutation. However, as mutations are fixed at some positions in a gene, the sites that are potentially variable also change because of changed functional constraints. This hypothesis as been termed the "covarion" hypothesis or when the model is applied to nucleotides, the "covariotide" hypothesis, The covarion-covariotide model has proven to be remarkably difficult to test. Here I examine a covariotide hypothesis for I I genes using a likelihood ratio test. I show that in nine of the genes examined a covariotide model provides a better explanation of the data than a model that does not allow constraints to change over time.