The probability of duplicate gene preservation by subfunctionalization.
The probability of duplicate gene preservation by subfunctionalization.
复制标题
通过亚功能化保存重复基因的概率。
DOI：
10.1093/genetics/154.1.459
复制
发表时间：
2000
期刊：
影响因子：
3.3
通讯作者：
Force,A
中科院分区：
文献类型：
--
作者：
Lynch,M;Force,A
通常认为，基因复制事件之后最常见的是一个突变事件，使一对中的一个成员沉默，而在极少数情况下，这对中的两个成员都被保留下来，因为一个获得了具有有益功能的突变，另一个保留了原始功能。然而，来自基因组复制事件的经验证据表明，基因复制在基因组中的保存更为普遍，并且保存时间远远超过该模型的预期，尽管一些基因复制明显进化出新的功能，但几乎没有证据表明这是复制基因保存的最常见机制。另一种假设是，基因重复经常通过亚功能化来保存，其中一对的两个成员经历退行性突变，将其联合水平和活动模式降低到单个祖先基因的水平和模式。我们考虑的方式，这种互补突变的重复基因保存的概率是由基因结构，连锁程度，突变率和影响，以及人口规模方面的修改。即使大多数突变导致子功能的完全丧失，如果长期有效群体大小在105或更小的数量级，特别是如果每个位点有两个以上的独立突变子功能，则重复基因保留的可能性是可观的。即使是中等程度的部分功能丧失突变也会大大提高保存的可能性。本文提出的模型导致的定量预测是一致的长期重复基因保存的频率上的观察和观察表明，一个共同的命运的成员的重复基因对的祖先基因的表达的组织特异性模式的分区。
It has often been argued that gene-duplication events are most commonly followed by a mutational event that silences one member of the pair, while on rare occasions both members of the pair are preserved as one acquires a mutation with a beneficial function and the other retains the original function. However, empirical evidence from genome duplication events suggests that gene duplicates are preserved in genomes far more commonly and for periods far in excess of the expectations under this model, and whereas some gene duplicates clearly evolve new functions, there is little evidence that this is the most common mechanism of duplicate-gene preservation. An alternative hypothesis is that gene duplicates are frequently preserved by subfunctionalization, whereby both members of a pair experience degenerative mutations that reduce their joint levels and patterns of activity to that of the single ancestral gene. We consider the ways in which the probability of duplicate-gene preservation by such complementary mutations is modified by aspects of gene structure, degree of linkage, mutation rates and effects, and population size. Even if most mutations cause complete loss-of-subfunction, the probability of duplicate-gene preservation can be appreciable if the long-term effective population size is on the order of 105or smaller, especially if there are more than two independently mutable subfunctions per locus. Even a moderate incidence of partial loss-of-function mutations greatly elevates the probability of preservation. The model proposed herein leads to quantitative predictions that are consistent with observations on the frequency of long-term duplicate gene preservation and with observations that indicate that a common fate of the members of duplicate-gene pairs is the partitioning of tissue-specific patterns of expression of the ancestral gene.