Statistical evidence for a more than 800-million-year-old evolutionarily conserved genomic region in our genome
Statistical evidence for a more than 800-million-year-old evolutionarily conserved genomic region in our genome
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DOI：
10.1007/s00239-004-2648-1
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发表时间：
2004-11-01
影响因子：
3.9
通讯作者：
Pontarotti, P
中科院分区：
文献类型：
--
作者：
Danchin, EGJ;Pontarotti, P
不同物种间基因组保守区域的识别对于重建它们最后的共同祖先至关重要。事实上，这些地区的保护在今天的物种（如果不是由于机会）可能构成的祖先保守的地区或从一系列独立的收敛事件的结果。比较物种的遗传距离越远，我们就越有可能重新排列，从而更难找到保护区。在这里，我们破译与脊椎动物（人类和斑马鱼）和节肢动物（果蝇和按蚊）之间的强有力的证据保守的基因组区域。这项工作包括一个强大的系统发育分析，结合严格的统计测试，允许显着拒绝一个“偶然”的保护假设。来自两个亲缘关系遥远的群体的四个不同物种的基因簇的保守性使得祖先保守的假设比个体趋同事件的假设更可能和简约。这一结果表明，尽管从它们最后的共同祖先开始，已经有超过8亿年的分歧和进化，但我们仍然可以揭示所有这些物种之间的保守性特征。斑马鱼、人类、果蝇和按蚊的最后共同祖先是所有原口动物和后口动物的共同祖先，被称为“原口动物”。“这项研究揭示了可能是祖先保守的基因簇，并构成了对Urbilateria基因组重建的进步。因此，这项工作可以更好地了解后生动物基因组的进化历史，包括我们的基因组。
Identification of conserved genomic regions between different species is crucial for the reconstruction of their last common ancestor. Indeed, such regions of conservation in today's species (if not due to chance) may either constitute stigmata of an ancestrally conserved region or result from a series of independent convergent events. The more phylogenetically distant the compared species are, the more we expect rearrangements and thus difficulties in finding regions of conservation. Here we decipher with strong evidence conserved genomic regions between vertebrates (human and zebrafish) and arthropods (Drosophila and Anopheles). This work includes a robust phylogenetic analysis in conjunction with a stringent statistical testing that allowed the significant rejection of a "by chance" conservation hypothesis. The conservation of gene clusters across four different species from two phylogenetically distant groups makes the hypothesis of an ancestral conservation more likely and parsimonious than the hypothesis of individual convergent events. This result shows that, in spite of more than 800 million years of divergence and evolution from their last common ancestor, we can still reveal stigmata of conservation between all these species. The last common ancestor of zebrafish, human, Drosophila, and Anopheles is the common ancestor of all protostomes and deuterostomes known as "Urbilateria." This study reveals clusters of probably ancestrally conserved genes and constitutes an advance toward the reconstruction of the genome of Urbilateria. Thus this work allows a better understanding of the evolutionary history of metazoan genomes, including our genome.