Swenson Krister M, Moret Bernard M E
Laboratory for Computational Biology and Bioinformatics, EPFL (Swiss Federal Institute of Technology), EPFL-IC-LCBB, INJ 230, Station 14, CH-1014 Lausanne, Switzerland.
BMC Bioinformatics. 2009 Jan 30;10 Suppl 1(Suppl 1):S7. doi: 10.1186/1471-2105-10-S1-S7.
Reconstructing complete ancestral genomes (at least in terms of their gene inventory and arrangement) is attracting much interest due to the rapidly increasing availability of whole genome sequences. While modest successes have been reported for mammalian and even vertebrate genomes, more divergent groups continue to pose a stiff challenge, mostly because current models of genomic evolution support too many choices.
We describe a novel type of genomic signature based on rearrangements that characterizes evolutionary changes that must be common to all minimal rearrangement scenarios; by focusing on global patterns of rearrangements, such signatures bypass individual variations and sharply restrict the search space. We present the results of extensive simulation studies demonstrating that these signatures can be used to reconstruct accurate ancestral genomes and phylogenies even for widely divergent collections.
Focusing on genome triples rather than genomes pairs unleashes the full power of evolutionary analysis. Our genomic signature captures shared evolutionary events and thus can form the basis of a robust analysis and reconstruction of evolutionary history.
由于全基因组序列的可得性迅速增加,重建完整的祖先基因组(至少在其基因清单和排列方面)正引起广泛关注。虽然在哺乳动物甚至脊椎动物基因组方面已取得一定成功,但对于分歧更大的类群,这仍然是一项严峻挑战,主要原因是当前的基因组进化模型支持过多选择。
我们描述了一种基于重排的新型基因组特征,它表征了所有最小重排情形中必然共有的进化变化;通过关注重排的全局模式,此类特征绕过个体变异并大幅限制搜索空间。我们展示了广泛模拟研究的结果,表明这些特征可用于重建准确的祖先基因组和系统发育树,即使对于分歧很大的类群集合也是如此。
关注基因组三元组而非基因组对可充分发挥进化分析的全部威力。我们的基因组特征捕捉了共享的进化事件,因此可构成对进化历史进行稳健分析和重建的基础。