Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Nature. 2011 May 5;473(7345):97-100. doi: 10.1038/nature09916. Epub 2011 Apr 10.
Whole-genome duplication (WGD), or polyploidy, followed by gene loss and diploidization has long been recognized as an important evolutionary force in animals, fungi and other organisms, especially plants. The success of angiosperms has been attributed, in part, to innovations associated with gene or whole-genome duplications, but evidence for proposed ancient genome duplications pre-dating the divergence of monocots and eudicots remains equivocal in analyses of conserved gene order. Here we use comprehensive phylogenomic analyses of sequenced plant genomes and more than 12.6 million new expressed-sequence-tag sequences from phylogenetically pivotal lineages to elucidate two groups of ancient gene duplications-one in the common ancestor of extant seed plants and the other in the common ancestor of extant angiosperms. Gene duplication events were intensely concentrated around 319 and 192 million years ago, implicating two WGDs in ancestral lineages shortly before the diversification of extant seed plants and extant angiosperms, respectively. Significantly, these ancestral WGDs resulted in the diversification of regulatory genes important to seed and flower development, suggesting that they were involved in major innovations that ultimately contributed to the rise and eventual dominance of seed plants and angiosperms.
全基因组复制（WGD）或多倍体化，随后伴随着基因丢失和二倍体化，长期以来一直被认为是动物、真菌和其他生物体（尤其是植物）进化的重要力量。被子植物的成功部分归因于与基因或全基因组复制相关的创新，但在分析保守基因顺序时，关于在单子叶植物和双子叶植物分化之前发生的拟议古老基因组复制的证据仍然存在争议。在这里，我们使用已测序植物基因组的综合系统基因组学分析以及来自系统发育关键谱系的超过 1260 万条新的表达序列标签序列，阐明了两组古老的基因复制——一组发生在现存种子植物的共同祖先中，另一组发生在现存被子植物的共同祖先中。基因复制事件强烈集中在 3.19 亿年前和 1.92 亿年前，这意味着在现存种子植物和现存被子植物的多样化之前，祖先谱系中分别发生了两次 WGD。重要的是，这些祖先 WGD 导致了对种子和花发育重要的调控基因的多样化，这表明它们参与了重大创新，最终促成了种子植物和被子植物的兴起和最终主导地位。
