线粒体基因组:结构特点和基因含量进化

Mt-genome revolution:structure and gene content

线粒体具有其自身的遗传系统——一个来自内共生的α-变形细菌祖先的基因组。线粒体基因组的生物学功能非常保守,仅涉及与线粒体有关的5个方面的过程:呼吸和氧化磷酸化、翻译、转录、RNA成熟和蛋白运输。真核生物线粒体基因含量的变化异常显著,在包括被子植物在内的各种真核生物相对频繁地发生线粒体基因丢失的同时,动物和某些植物类群的线粒体基因含量相对来说则比较稳定。tRNA基因含量的变化反映了线粒体对来自核的tRNA在使用上的差异,而蛋白基因含量的变化主要是由于功能性的基因转移到核所造成的。对线粒体基因组学领域中有关基因组起源、结构和基因含量进化方面的研究进行综述。

Mitochondria have their own genetic system-a genome originating from an endosymbiotic α-proteobacterial ancestor.The genetic function of mt-genome is well-conserved,being involved in a maximum of five mitochondrial processes： respiration and oxidative phosphorylation,translation,transcription,RNA maturation and protein import.Mitochondrial gene content is highly variable across extant eukaryotes.All animals,some plants,and certain other groups of eukaryotes are relatively static in mitochondrial gene content,whereas other lineages have experienced relatively frequent gene loss.Diversity in tRNA gene content primarily reflects differential usage of imported tRNAs from nuclear,but for the protein-coding genes,this diversity reflects differential degrees of functional gene transfer to the nucleus.This article reviews the advances in the field of mitogenomics,especially for the origin,organization and content of mt-genome.