Exposing the fitness contribution of duplicated genes
Exposing the fitness contribution of duplicated genes
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DOI：
10.1038/ng.123
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发表时间：
2008-05-01
期刊：
影响因子：
30.8
通讯作者：
Kishony, Roy
中科院分区：
文献类型：
--
作者：
DeLuna, Alexander;Vetsigian, Kalin;Kishony, Roy
酵母全基因组复制（WGD）产生的重复基因往往是可有可无的——去除一个拷贝几乎没有或没有表型影响（1,2）。然而，这种可有可无性究竟是反映了祖先功能的不重要，还是来自旁系同源基因的补偿作用，尚不清楚（3 - 7）。在此，通过基于精确竞争的单基因和双基因缺失适应性代价测量，我们估算了WGD重复基因在代谢中的显性适应性贡献，并确定了其祖先复制前功能的重要性范围。我们发现旁系同源基因之间的功能重叠足以解释单个WGD基因明显的可有可无性。此外，通过协同上位性程度估算的祖先功能适应性值下限，至少与删除单个非WGD基因的平均适应性代价一样大。这些结果表明，WGD基因编码的大多数代谢功能在当下是重要的，在复制之时也是重要的。
Duplicate genes from the whole-genome duplication (WGD) in yeast are often dispensable-removing one copy has little or no phenotypic consequence(1,2). It is unknown, however, whether such dispensability reflects insignificance of the ancestral function or compensation from paralogs(3-7). Here, using precise competition-based measurements of the fitness cost of single and double deletions, we estimate the exposed fitness contribution of WGD duplicate genes in metabolism and bound the importance of their ancestral pre-duplication function. We find that the functional overlap between paralogs sufficiently explains the apparent dispensability of individual WGD genes. Furthermore, the lower bound on the fitness value of the ancestral function, which is estimated by the degree of synergistic epistasis, is at least as large as the average fitness cost of deleting single non-WGD genes. These results suggest that most metabolic functions encoded by WGD genes are important today and were also important at the time of duplication.