Body mass-corrected molecular rate for bird mitochondrial DNA
Body mass-corrected molecular rate for bird mitochondrial DNA
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DOI：
10.1111/mec.13780
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发表时间：
2016-09-01
影响因子：
4.9
通讯作者：
Fuchs, Jerome
中科院分区：
文献类型：
--
作者：
Nabholz, Benoit;Lanfear, Robert;Fuchs, Jerome
线粒体DNA仍然是最广泛使用的分子标记之一，以重建亲缘关系密切的鸟类的亲缘关系和地理分布。有人提出鸟类线粒体基因组以每百万年每个位点0.01个替换的恒定速率进化，也就是说它们根据严格的分子钟进化。该分子钟常用于鸟类线粒体基因组发生和分子测年的研究。然而，线粒体基因组进化的速率在鸟类物种之间存在差异，并与生活史特征如体重和世代时间相关。这些相关性可能会导致分子测年研究中的系统偏差，假设严格的分子钟。在这项研究中，我们通过估计鸟类的校正分子速率来克服这个问题。使用475个物种的完整或接近完整的线粒体基因组，我们发现鸟类的体重和替代率之间存在很强的关系。我们利用这些信息来建立模型，使用鸟类的体重来估计它们在广泛的常见线粒体标记物中的替代率。我们证明了使用这些校正的分子速率在两个最近发表的数据集。在一种情况下，我们获得的分子日期是使用严格分子钟获得的估计值的两倍。我们希望这种估计分子速率的方法将提高未来鸟类分子测年研究的准确性。
Mitochondrial DNA remains one of the most widely used molecular markers to reconstruct the phylogeny and phylogeography of closely related birds. It has been proposed that bird mitochondrial genomes evolve at a constant rate of similar to 0.01 substitution per site per million years, that is that they evolve according to a strict molecular clock. This molecular clock is often used in studies of bird mitochondrial phylogeny and molecular dating. However, rates of mitochondrial genome evolution vary among bird species and correlate with life history traits such as body mass and generation time. These correlations could cause systematic biases in molecular dating studies that assume a strict molecular clock. In this study, we overcome this issue by estimating corrected molecular rates for birds. Using complete or nearly complete mitochondrial genomes of 475 species, we show that there are strong relationships between body mass and substitution rates across birds. We use this information to build models that use bird species' body mass to estimate their substitution rates across a wide range of common mitochondrial markers. We demonstrate the use of these corrected molecular rates on two recently published data sets. In one case, we obtained molecular dates that are twice as old as the estimates obtained using the strict molecular clock. We hope that this method to estimate molecular rates will increase the accuracy of future molecular dating studies in birds.