Zhang Peng, Min Wanli, Li Wen-Hsiung
Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA.
Gene. 2004 Nov 24;342(2):263-8. doi: 10.1016/j.gene.2004.08.001.
We studied the age distribution of duplicate genes in each of four eukaryotic genomes: human, Arabidopsis thaliana, Caenorhabditis elegans, and Drosophila melanogaster. The four distributions differ greatly from each other, contrary to the previous proposal of a universal L-shaped distribution in all eukaryotic genomes studied. Indeed, only the distribution in humans is L-shaped. The distribution in Arabidopsis is consistent with the hypothesis of an ancient genome duplication with no recent burst of duplication events, while the distribution in C. elegans is nearly uniform. We also applied a nonparametric method to the human distribution to show that the rate of loss of duplicate genes decreases over time, contrary to the proposal of an exponential decay. One possible explanation of the decreasing rate of loss of duplicate genes over time could be rapid functional divergence between duplicate genes, providing an advantage for the retention of both duplicates.
我们研究了四种真核生物基因组（人类、拟南芥、秀丽隐杆线虫和黑腹果蝇）中重复基因的年龄分布。这四种分布彼此差异很大，这与之前关于所有已研究真核生物基因组中普遍存在L形分布的提议相反。实际上，只有人类基因组的分布呈L形。拟南芥的分布与远古基因组加倍且近期没有加倍事件爆发的假设一致，而秀丽隐杆线虫的分布几乎是均匀的。我们还对人类基因组分布应用了一种非参数方法，以表明重复基因的丢失率随时间下降，这与指数衰减的提议相反。重复基因丢失率随时间下降的一个可能解释是重复基因之间功能快速分化，这为保留两个重复基因提供了优势。
