Shotgun Mitogenomics Provides a Reference Phylogenetic Framework and Timescale for Living Xenarthrans.
Shotgun Mitogenomics Provides a Reference Phylogenetic Framework and Timescale for Living Xenarthrans.
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shot弹枪有丝分裂基因组提供了一个参考系统发育框架和用于活Xenarthrans的时间尺度。
DOI：
10.1093/molbev/msv250
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发表时间：
2016-03
影响因子：
10.7
通讯作者：
Delsuc F
中科院分区：
文献类型：
--
作者：
Gibb GC;Condamine FL;Kuch M;Enk J;Moraes-Barros N;Superina M;Poinar HN;Delsuc F
Xenarthra(螳螂、树懒和食蚁兽)是胎盘哺乳动物的四大支系之一。尽管它们在哺乳动物中具有系统发育的特殊性，但所描述的31个物种的参考系统发育仍然缺乏。在这里，我们使用Illumina鸟枪测序技术组装了33个新的完整线粒体基因组，确立了Xenarthra作为第一个在物种水平上完全测序的主要胎盘支系。由此产生的数据集使我们能够重建一个强大的系统发育框架和时间尺度，这与以前在属一级使用核基因进行的研究是一致的。将现存的异种生物的全部物种多样性结合起来，表明在异种生物的系统学和物种定义上存在许多不一致之处。为了更好地反映它们的远古分异，我们建议将其划分为两个不同的科，Dasypodidae(Dasypodines)和Chlamyphoridae(Ephractine、Chlamyphorines和Tolypeutines)。随着在法属圭亚那发现了一个不同的谱系，长鼻犰螂(Dasypus属)的物种划分似乎比预期的要复杂得多。多样性分析表明，Xenarthra是一个古老的支系，随着时间的推移，多样化的速度是恒定的，物种周转是由高度但持续的灭绝驱动的。我们还检测到物种形成率与过去的温度波动之间存在显著的负相关关系，物种形成率的增加与过去15年观察到的总体降温相对应。生物地理重建确定亚马逊热带雨林生物群和圭亚那盾是异种生物进化史的摇篮，随后扩散到更开阔和干燥的栖息地。
Xenarthra (armadillos, sloths, and anteaters) constitutes one of the four major clades of placental mammals. Despite their phylogenetic distinctiveness in mammals, a reference phylogeny is still lacking for the 31 described species. Here we used Illumina shotgun sequencing to assemble 33 new complete mitochondrial genomes, establishing Xenarthra as the first major placental clade to be fully sequenced at the species level for mitogenomes. The resulting data set allowed the reconstruction of a robust phylogenetic framework and timescale that are consistent with previous studies conducted at the genus level using nuclear genes. Incorporating the full species diversity of extant xenarthrans points to a number of inconsistencies in xenarthran systematics and species definition. We propose to split armadillos into two distinct families Dasypodidae (dasypodines) and Chlamyphoridae (euphractines, chlamyphorines, and tolypeutines) to better reflect their ancient divergence, estimated around 42 Ma. Species delimitation within long-nosed armadillos (genus Dasypus) appeared more complex than anticipated, with the discovery of a divergent lineage in French Guiana. Diversification analyses showed Xenarthra to be an ancient clade with a constant diversification rate through time with a species turnover driven by high but constant extinction. We also detected a significant negative correlation between speciation rate and past temperature fluctuations with an increase in speciation rate corresponding to the general cooling observed during the last 15 My. Biogeographic reconstructions identified the tropical rainforest biome of Amazonia and the Guiana Shield as the cradle of xenarthran evolutionary history with subsequent dispersions into more open and dry habitats.