THE MAIN REGULATORY REGION OF MAMMALIAN MITOCHONDRIAL-DNA - STRUCTURE-FUNCTION MODEL AND EVOLUTIONARY PATTERN
THE MAIN REGULATORY REGION OF MAMMALIAN MITOCHONDRIAL-DNA - STRUCTURE-FUNCTION MODEL AND EVOLUTIONARY PATTERN
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DOI：
10.1007/bf02100199
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发表时间：
1991-07-01
影响因子：
3.9
通讯作者：
SBISA, E
中科院分区：
文献类型：
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作者：
SACCONE, C;PESOLE, G;SBISA, E
哺乳动物线粒体基因组的主要调控区（D-环）的进化进行了分析，通过比较8种哺乳动物的序列：人类，普通黑猩猩，侏儒黑猩猩，海豚，牛，大鼠，小鼠和兔。 通过优化所有这些物种共有的序列相似性，获得了序列的最佳比对。两个外周左和右D-环结构域，其中包含迄今发现的主要调控元件，以物种特异性的方式迅速进化，在长度和碱基组成上产生异质性。 它们倾向于插入和缺失元件，并通过复制滑动产生短重复序列。 然而，在这些区域中的一些序列块和类似的苜蓿叶状结构的保存，表明在所有哺乳动物物种的线粒体基因组的调控机制的基本相似性，我们发现，特别是在正确的域，显着的相似性四膜虫的线粒体（mt）和核DNA的端粒序列的嗜热四膜虫。 这些序列可以被解释为线粒体线性形式祖先中端粒的遗迹，或者可能只是代表RNA灵长类酶样酶的有效模板。由于其独特的进化，这两个外围结构域无法用于定量估计哺乳动物物种之间的遗传距离。 另一方面，在进化过程中高度保守的中心域，表现为一个很好的分子clock.Reliable估计的时间之间的分歧密切和远距离相关的物种，从中心域使用马尔可夫模型，并假设非均匀进化的核苷酸位点。
The evolution of the main regulatory region (D-loop) of the mammalian mitochondrial genome was analyzed by comparing the sequences of eight mammalian species: human, common chimpanzee, pygmy chimpanzee, dolphin, cow, rat, mouse, and rabbit. The best alignment of the sequences was obtained by optimization of the sequence similarities common to all these species.The two peripheral left and right D-loop domains, which contain the main regulatory elements so far discovered, evolved rapidly in a species-specific manner generating heterogeneity in both length and base composition. They are prone to the insertion and deletion of elements and to the generation of short repeats by replication slippage. However, the preservation of some sequence blocks and similar cloverleaf-like structures in these regions, indicates a basic similarity in the regulatory mechanisms of the mitochondrial genome in all mammalian species.We found, particularly in the right domain, significant similarities to the telomeric sequences of the mitochondrial (mt) and nuclear DNA of Tetrahymena thermophila. These sequences may be interpreted as relics of telomeres present in ancestral linear forms of mtDNA or may simply represent efficient templates of RNA primase-like enzymes.Due to their peculiar evolution, the two peripheral domains cannot be used to estimate in a quantitative way the genetic distances between mammalian species. On the other hand the central domain, highly conserved during evolution, behaves as a good molecular clock.Reliable estimates of the times of divergence between closely and distantly related species were obtained from the central domain using a Markov model and assuming nonhomogeneous evolution of nucleotide sites.