Supply P, Mazars E, Lesjean S, Vincent V, Gicquel B, Locht C
Laboratoire des Mécanismes Moléculaires de la Pathogenèse Bactérienne, INSERM U447, France.
Mol Microbiol. 2000 May;36(3):762-71. doi: 10.1046/j.1365-2958.2000.01905.x.
Mycobacterial interspersed repetitive units (MIRUs) are 40-100 bp DNA elements often found as tandem repeats and dispersed in intergenic regions of the Mycobacterium tuberculosis complex genomes. The M. tuberculosis H37Rv chromosome contains 41 MIRU loci. After polymerase chain reaction (PCR) and sequence analyses of these loci in 31 M. tuberculosis complex strains, 12 of them were found to display variations in tandem repeat copy numbers and, in most cases, sequence variations between repeat units as well. These features are reminiscent of those of certain human variable minisatellites. Of the 12 variable loci, only one was found to vary among genealogically distant BCG substrains, suggesting that these interspersed bacterial minisatellite-like structures evolve slowly in mycobacterial populations.
分枝杆菌散布重复单元（MIRUs）是40 - 100碱基对的DNA元件，常以串联重复形式存在，并分散于结核分枝杆菌复合群基因组的基因间区域。结核分枝杆菌H37Rv染色体含有41个MIRU位点。对31株结核分枝杆菌复合群菌株的这些位点进行聚合酶链反应（PCR）和序列分析后，发现其中12个位点的串联重复拷贝数存在变异，并且在大多数情况下，重复单元之间也存在序列变异。这些特征使人联想到某些人类可变微卫星的特征。在这12个可变位点中，仅发现1个位点在亲缘关系较远的卡介苗亚菌株之间存在变异，这表明这些散布的细菌类微卫星结构在分枝杆菌群体中进化缓慢。
