Quantifying the decanalizing effects of spontaneous mutations in rhabditid nematodes
Quantifying the decanalizing effects of spontaneous mutations in rhabditid nematodes
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DOI：
10.1086/589455
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发表时间：
2008-08-01
影响因子：
2.9
通讯作者：
Baer, Charles F.
中科院分区：
文献类型：
--
作者：
Baer, Charles F.
管道化的进化，表型对环境或遗传扰动的稳健性，最近引起了相当大的兴趣。理解任何表型进化的关键一步是描述突变引入性状遗传变异的速率（突变方差，V M）和突变对性状平均值（DM）的平均定向效应。在本研究中，对线虫的两组突变积累系进行了产量和体体积变异参数的量化，并与性状本身的突变参数进行了比较。出现了四个结果：(1)自发突变持续地使表型失联；(2)去analization的突变参数vm（量化为突变遗传力）和DM与性状本身的相同参数具有相同的数量级；(3)渠化的突变参数与各类群性状本身的突变参数大致相关；(4)没有证据表明残留的分离过优位点会导致管道化的衰退。这些结果表明，渠化很容易进化，任何导致突变积累的进化因素平均而言都会使表型去渠化。
The evolution of canalization, the robustness of the phenotype to environmental or genetic perturbation, has attracted considerable recent interest. A key step toward understanding the evolution of any phenotype is characterizing the rate at which mutation introduces genetic variation for the trait ( the mutational variance, V M) and the average directional effects of mutations on the trait mean (DM). In this study, the mutational parameters for canalization of productivity and body volume are quantified in two sets of mutation accumulation lines of nematodes in the genus Caenorhabditis and are compared with the mutational parameters for the traits themselves. Four results emerge: (1) spontaneous mutations consistently decanalize the phenotype; (2) the mutational parameters for decanalization, V M ( quantified as mutational heritability) and DM, are of the same order of magnitude as the same parameters for the traits themselves; (3) the mutational parameters for canalization are roughly correlated with the parameters for the traits themselves across taxa; and (4) there is no evidence that residual segregating overdominant loci contribute to the decay of canalization. These results suggest that canalization is readily evolvable and that any evolutionary factor that causes mutations to accumulate will, on average, decanalize the phenotype.