Control Region Length Dynamics Potentially Drives Amino Acid Evolution in Tarsier Mitochondrial Genomes
Control Region Length Dynamics Potentially Drives Amino Acid Evolution in Tarsier Mitochondrial Genomes
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DOI：
10.1007/s00239-014-9631-2
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发表时间：
2014-08-01
影响因子：
3.9
通讯作者：
Pfenninger, Markus
中科院分区：
文献类型：
--
作者：
Merker, Stefan;Thomas, Sarah;Pfenninger, Markus
分子进化的模式和过程对遗传学和地理学的推论有着重要的影响。在灵长类动物中，进化速度的转变被认为是线粒体和核DNA研究结果对比的基本原理。虽然后者现在似乎已经解决，我们测序了三个苏拉威西眼镜猴（Tarsius dentatus，T。lariang和T. wallacei），并分析了眼镜猴和其他灵长类动物之间的替代率，以推断分子进化的驱动过程。我们发现大量的长度多态性的D-环内的眼镜猴个体，但它们之间的主要长度变化不大，无论物种。长度变异是由于CSB结构域中的重复元件-35 bp长的小卫星基序和6 bp长的微卫星基序造成的。氨基酸进化率是第二高的主要灵长类类群之间相对于核苷酸取代率。我们观察到许多激进的可能改变功能的氨基酸的变化，很少被驱动的积极选择，因此潜在的轻微有害或中性。我们推测，所观察到的模式增加的氨基酸进化速率在眼镜猴线粒体基因组可能是由搭便车的轻微有害的突变与有利的D-环长度变异选择最大限度地提高复制成功的细胞或细胞内的。
Patterns and processes of molecular evolution critically influence inferences in phylogeny and phylogeography. Within primates, a shift in evolutionary rates has been identified as the rationale for contrasting findings from mitochondrial and nuclear DNA studies as to the position of Tarsius. While the latter now seems settled, we sequenced complete mitochondrial genomes of three Sulawesi tarsiers (Tarsius dentatus, T. lariang, and T. wallacei) and analyzed substitution rates among tarsiers and other primates to infer driving processes of molecular evolution. We found substantial length polymorphism of the D-loop within tarsier individuals, but little variation of predominant lengths among them, regardless of species. Length variation was due to repetitive elements in the CSB domain-minisatellite motifs of 35 bp length and microsatellite motifs of 6 bp length. Amino acid evolutionary rates were second highest among major primate taxa relative to nucleotide substitution rates. We observed many radical possibly function-altering amino acid changes that were rarely driven by positive selection and thus potentially slightly deleterious or neutral. We hypothesize that the observed pattern of an increased amino acid evolutionary rate in tarsier mitochondrial genomes may be caused by hitchhiking of slightly deleterious mutations with favored D-loop length variants selected for maximizing replication success within the cell or the mitochondrion.