Ohta T
National Institute of Genetics, Mishima, Japan.
Genetics. 1989 Nov;123(3):579-84. doi: 10.1093/genetics/123.3.579.
Evolution by compensatory mutations is accelerated by gene duplication because selective constraint is relaxed by gene redundancy. A mutation is called compensatory if it corrects the effect of an earlier deleterious mutation. Without duplication, Kimura has shown that the time for spreading of compensatory mutations is much reduced by tight linkage between the two chromosomal sites of mutations. In this report, the time for spreading with gene duplication was studied by using the diffusion equation method of Kimura, together with computer simulations. It was shown that, when 2Nv- is much less than unity, the time for spreading is greatly shortened by gene duplication as compared with the case of complete linkage between the two sites of mutations, where 2N is the effective population size (haploid) and v- is the rate of compensatory mutations. However, if 2Nv- greater than 1, gene duplication is not effective for accelerating the evolution by such mutations.
基因重复会加速通过补偿性突变实现的进化，因为基因冗余会放松选择限制。如果一个突变能够纠正早期有害突变的影响，那么它就被称为补偿性突变。木村资生表明，在没有基因重复的情况下，由于两个突变染色体位点之间的紧密连锁，补偿性突变的传播时间会大大缩短。在本报告中，我们使用木村资生的扩散方程方法并结合计算机模拟，研究了基因重复情况下的传播时间。结果表明，当2Nv-远小于1时，与两个突变位点完全连锁的情况相比，基因重复会大大缩短传播时间，其中2N是有效种群大小（单倍体），v-是补偿性突变的速率。然而，如果2Nv-大于1，基因重复对于通过此类突变加速进化并不有效。
