Keim P, Klevytska A M, Price L B, Schupp J M, Zinser G, Smith K L, Hugh-Jones M E, Okinaka R, Hill K K, Jackson P J
Department of Biological Sciences, Northern Arizona University, Flagstaff 86011-5640, USA.
J Appl Microbiol. 1999 Aug;87(2):215-7. doi: 10.1046/j.1365-2672.1999.00873.x.
Molecular typing of Bacillus anthracis has been extremely difficult due to the lack of polymorphic DNA markers. We have identified nine novel variable number tandemly repeated loci from previously known amplified fragment length polymorphism markers or from the DNA sequence. In combination with the previously known vrrA locus, these markers provide discrimination power to genetically characterize B. anthracis isolates. The variable number tandem repeat (VNTR) loci are found in both gene coding (genic) and non-coding (non-genic) regions. The genic differences are 'in frame' and result in additions or deletion of amino acids to the predicted proteins. Due the rarity of molecular differences, the VNTR changes represent a significant portion of the genetic variation found within B. anthracis. This variation could represent an important adaptive mechanism. Marker similarity and differences among diverse isolates have identified seven major diversity groups that may represent the only world-wide B. anthracis clones. The lineages reconstructed using these data may reflect the dispersal and evolution of this pathogen.
由于缺乏多态性DNA标记，炭疽芽孢杆菌的分子分型一直极具难度。我们从先前已知的扩增片段长度多态性标记或DNA序列中鉴定出了9个新的可变数目串联重复基因座。与先前已知的vrrA基因座相结合，这些标记为炭疽芽孢杆菌分离株的基因特征鉴定提供了鉴别力。可变数目串联重复（VNTR）基因座存在于基因编码（基因）区和非编码（非基因）区。基因差异是“框内”的，会导致预测蛋白质中氨基酸的添加或缺失。由于分子差异罕见，VNTR变化占炭疽芽孢杆菌内发现的遗传变异的很大一部分。这种变异可能代表一种重要的适应性机制。不同分离株之间标记的相似性和差异确定了7个主要的多样性组，它们可能代表了全球仅有的炭疽芽孢杆菌克隆。利用这些数据重建的谱系可能反映了这种病原体的传播和进化。
