鱼类线粒体DNA重排研究进展

Rearrangement of mitochondrial genome in fishes

一般认为鱼类线粒体基因组在结构上具有高度的保守性，但是通过分析NCBI数据库中的1 255种鱼类线粒体基因组全序列（截至2013年11月3日），发现～52种鱼线粒体基因组发生了重排。进一步的分析发现这些重排具有3种类型：滑移（shuffling）、移位（translocation）和倒置（inversion），并多发生于WANCY基因簇、IQM基因簇、ND6基因、控制区（D-loop）及其邻接基因等区域。该文根据已报道的4种常见的解释重排的模型：复制-随机丢失（duplication-random loss）、复制-非随机丢失（duplication-nonrandom loss）、线粒体内的重组（intramitochondrial recombination）以及由tRNA基因错误起始引起的复制（tRNA miss-priming model）解释了鱼类重排产生的可能机制，并探讨了重排现象在鱼类系统发生研究中的应用，以期为鱼类线粒体的进化研究提供科学依据。

Generally, the mitochondrial genome is characterized by the property of highly conserved organization. After comparing the 1,255 fish complete mitogenome sequences deposited in GenBank （as of Nov. 3, 2013）, approximately 52 complete mitogenomes are found to have been rearranged. Of these species, three types of rearrangement-shuffling, translocation, and inversion-have been found. Further analysis shows that the sites of the rearrangements occur frequently in WANCY cluster, IQM cluster, ND6 gene, control region （D-loop） and its adjacent genes. Based on the four models that explain the gene rearrangements commonly adopted by scientists, we attempted to infer the possible mechanisms for the three types of gene rearrangement as well as the application of gene rearrangement in phylogenetic studies.