No variation and low synonymous substitution rates in coral mtDNA despite high nuclear variation.
No variation and low synonymous substitution rates in coral mtDNA despite high nuclear variation.
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DOI：
10.1186/1471-2148-6-24
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发表时间：
2006-03-16
影响因子：
3.4
通讯作者：
Hellberg ME
中科院分区：
文献类型：
--
作者：
Hellberg ME
大多数动物的线粒体DNA(MtDNA)比核DNA进化得更快，通常表现出更高的种内多态和种群细分水平。相比之下，珊瑚虫(珊瑚、海扇及其近亲)的线粒体DNA似乎进化缓慢。已经报道了几个珊瑚虫mtDNA进化缓慢，然而，如果没有平行的核变异调查或校准的同义替换率，很难将这种缓慢的进化放在系统发育的背景下进行，这可能允许跨分类群进行定量的比率比较。在这里，我调查了一种已知具有高水平核基因变异的珊瑚物种(Balanophyllia Elegans)的线粒体基因编码区的变异，并通过与另一种珊瑚(球状管藻)的比较来估计mtDNA替换率的同义率。所调查的线粒体DNA(630bp的细胞色素氧化酶I亚基)在来自18个种群的个体中是不变的，这些种群跨越3000公里的范围，尽管这些种群的等位酶存在很高的变异和种群细分。线虫和球虫之间的同义替换率(0.05%/座/106年)与大多数植物中的相似，但比大多数动物的典型替换率低50-100倍。此外，虽然大多数动物的mtDNA替换显示出强烈的过渡倾向，但这些珊瑚的mtDNA并非如此。线粒体核苷酸替换的缓慢速度导致珊瑚种内mtDNA变异水平较低，即使在核基因座发生变化时也是如此。线粒体DNA进化缓慢似乎是真核生物的基本条件。线粒体DNA替换率突然单向地由慢变快。这种转变可能源于只有一个或几个线粒体特异的DNA修复或复制基因的丢失。
The mitochondrial DNA (mtDNA) of most animals evolves more rapidly than nuclear DNA, and often shows higher levels of intraspecific polymorphism and population subdivision. The mtDNA of anthozoans (corals, sea fans, and their kin), by contrast, appears to evolve slowly. Slow mtDNA evolution has been reported for several anthozoans, however this slow pace has been difficult to put in phylogenetic context without parallel surveys of nuclear variation or calibrated rates of synonymous substitution that could permit quantitative rate comparisons across taxa. Here, I survey variation in the coding region of a mitochondrial gene from a coral species (Balanophyllia elegans) known to possess high levels of nuclear gene variation, and estimate synonymous rates of mtDNA substitution by comparison to another coral (Tubastrea coccinea). The mtDNA surveyed (630 bp of cytochrome oxidase subunit I) was invariant among individuals sampled from 18 populations spanning 3000 km of the range of B. elegans, despite high levels of variation and population subdivision for allozymes over these same populations. The synonymous substitution rate between B. elegans and T. coccinea (0.05%/site/106 years) is similar to that in most plants, but 50–100 times lower than rates typical for most animals. In addition, while substitutions to mtDNA in most animals exhibit a strong bias toward transitions, mtDNA from these corals does not. Slow rates of mitochondrial nucleotide substitution result in low levels of intraspecific mtDNA variation in corals, even when nuclear loci vary. Slow mtDNA evolution appears to be the basal condition among eukaryotes. mtDNA substitution rates switch from slow to fast abruptly and unidirectionally. This switch may stem from the loss of just one or a few mitochondrion-specific DNA repair or replication genes.
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影响因子：
64.8
作者：
CUNNINGHAM, CW;BLACKSTONE, NW;BUSS, LW
通讯作者：
BUSS, LW
影响因子：
2.4
作者：
Duran, S;Pascual, M;Turon, X
通讯作者：
Turon, X
影响因子：
3.5
作者：
Fukami, H;Knowlton, N
通讯作者：
Knowlton, N
影响因子：
14.9
作者：
Eisen, JA
通讯作者：
Eisen, JA
影响因子：
3.5
作者：
Fenner, D;Banks, K
通讯作者：
Banks, K