Department of Biosciences and Biotechnology, Banasthali University, Banasthali, Rajasthan, India.
OMICS. 2011 Nov;15(11):783-9. doi: 10.1089/omi.2011.0074. Epub 2011 Oct 19.
Simple sequence repeats (SSRs) or microsatellites constitute a countable portion of genomes. However, the significance of SSRs in organelle genomes has not been completely understood. The availability of organelle genome sequences allows us to understand the organization of SSRs in their genic and intergenic regions. In the current study we surveyed the patterns of SSRs in mitochondrial genomes of different taxa of plants. A total of 16 mitochondrial genomes, from algae to angiosperms, have been considered to analyze the pattern of simple sequence repeats present in them. Based on study, the mononucleotide repeats of A/T were found to be more prevalent in mitochondrial genomes over other repeat types. The dinucleotides repeats, TA/AT, were the second most numerous, whereas tri-, tetra-, and pentanucleotide repeats were in less number and present in intronic or intergenic portions only. Mononucleotide repeats prevailed in protein-coding exonic portions of all organisms. These results indicates that microsatellite pattern in mitochondrial genomes is different from nuclear genomes and also focuses on organization and diversity at SSR locuses in mitochondrial genomes. This is the novel report of microsatellite polymorphism in plant mitochondrion on whole genome level.
简单序列重复（SSR）或微卫星构成了基因组的一部分。然而，SSR 在细胞器基因组中的意义尚未完全理解。细胞器基因组序列的可用性使我们能够了解 SSR 在基因和基因间区域的组织。在本研究中，我们调查了不同植物类群线粒体基因组中 SSR 的模式。总共考虑了 16 个线粒体基因组，从藻类到被子植物，以分析它们中存在的简单序列重复的模式。基于研究，发现线粒体基因组中 A/T 的单核苷酸重复比其他重复类型更为普遍。二核苷酸重复 TA/AT 是第二多的，而三核苷酸、四核苷酸和五核苷酸重复则较少，仅存在于内含子或基因间部分。单核苷酸重复在所有生物体的蛋白质编码外显子部分占主导地位。这些结果表明，线粒体基因组中的微卫星模式与核基因组不同，还侧重于线粒体基因组中 SSR 位置的组织和多样性。这是关于植物线粒体全基因组水平微卫星多态性的新报告。
