Department of Biochemistry, Comenius University, Mlynska dolina CH-1, 842 15 Bratislava, Slovak republic.
Nucleic Acids Res. 2011 May;39(10):4202-19. doi: 10.1093/nar/gkq1345. Epub 2011 Jan 25.
Mitochondrial genome diversity in closely related species provides an excellent platform for investigation of chromosome architecture and its evolution by means of comparative genomics. In this study, we determined the complete mitochondrial DNA sequences of eight Candida species and analyzed their molecular architectures. Our survey revealed a puzzling variability of genome architecture, including circular- and linear-mapping and multipartite linear forms. We propose that the arrangement of large inverted repeats identified in these genomes plays a crucial role in alterations of their molecular architectures. In specific arrangements, the inverted repeats appear to function as resolution elements, allowing genome conversion among different topologies, eventually leading to genome fragmentation into multiple linear DNA molecules. We suggest that molecular transactions generating linear mitochondrial DNA molecules with defined telomeric structures may parallel the evolutionary emergence of linear chromosomes and multipartite genomes in general and may provide clues for the origin of telomeres and pathways implicated in their maintenance.
线粒体基因组在亲缘关系密切的物种中的多样性为通过比较基因组学研究染色体结构及其进化提供了极好的平台。在这项研究中，我们测定了 8 种假丝酵母属物种的完整线粒体 DNA 序列，并分析了它们的分子结构。我们的调查显示，基因组结构具有令人费解的可变性，包括环状和线状作图以及多部分线性形式。我们提出，在这些基因组中鉴定出的大反向重复的排列在改变其分子结构中起着关键作用。在特定的排列中，反向重复似乎作为分辨率元件起作用，允许在不同拓扑结构之间进行基因组转换，最终导致基因组碎片化成为多个线性 DNA 分子。我们建议，产生具有定义端粒结构的线性线粒体 DNA 分子的分子转换可能与线性染色体和多部分基因组的一般进化出现平行，并可能为端粒的起源及其维持所涉及的途径提供线索。
