Divergence evolution of duplicated yeast genes in protein interaction network | 酵母重复基因在蛋白质互作网络中的分歧进化

Chinese. 分析全基因组重复后，蛋白质互作网络对重复基因分歧模式的作用机制。结合高精度的蛋白质互作数据集和具有相同进化年代的重复基因数据集，在全基因组范围关联分析拷贝间进化距离与网络结构的相关性，并通过对拷贝间连接水平的差异程度分类，分析不同阶段网络结构对基因功能的影响。重复基因两拷贝间的进化距离与其祖先基因在网络中的连接水平呈显著负相关，与重复基因间的连接度差异率呈显著正相关；网络结构完全歧化的重复基因间的非同义替换均值，较未完全歧化的重复基因显著高出30.2%。网络结构对重复基因的进化起调节作用，网络系统在保持核心稳定的同时，使外围组分发生了更大变化；重复基因在网络结构改变的前期为基因组提供功能冗余，但在网络结构差别较大后，显著增加的突变更有利于基因新功能的产生。

English. The purpose of present study was to investigate the regulatory mechanism of interaction network on the divergence of duplicate genes after whole genome duplication. Taking advantage of highly accurate protein and genetic interaction data set by incorporating the information of yeast duplicate genes sharing the same age, we analyzed the correlation between the evolutionary distance of each pair of duplicate gene and ancestral gene connectivity level on a genome scale. Moreover, the duplicate genes were classified by the divergence rate to analyse the impact of interaction network on the different stages of divergence. The result showes that there was a significant correlation between ancient gene connectivity level of ancient gene and evolutionary distance between two duplicate copies, a significant correlation between divergence rate and evolutionary distance between two duplicate copies. Moreover, the average mean of synonymous substitution of complete divergent genes was 30.2% higher than that of incomplete pairs. These results suggest that the interaction network regulates the evolution of duplicated genes. The mechanism ensures that there is a relatively stable interaction network core with an increasingly changing edge. Moreover, duplicate genes tend to provide functional redundancy during early stage of protein interactions turnover; whereas duplicates become beneficial to the emergence of functional novelty by increasing the number of mutations when interactions vary greatly.