McClelland M, Petersen C, Welsh J
California Institute of Biological Research, La Jolla, California 92037.
J Clin Microbiol. 1992 Jun;30(6):1499-504. doi: 10.1128/jcm.30.6.1499-1504.1992.
Intergenic tRNA spacers from strains of streptococcal groups A, B, and G were amplified by using the polymerase chain reaction (PCR) at low stringency with consensus tRNA gene primers. Cloning and sequencing showed that many of the homologous intergenic spacers differed in length between species. The sequences of the tRNA genes that flank these polymorphic spacers were determined and used to synthesize fully complementary primers. With these primers at high stringency, PCR products which varied in lengths from 53 to 71 bp, depending on the species or strain, were obtained from streptococcal DNAs, even in the presence of a 1,000-fold mass excess of human DNA. PCR products, the lengths of which could also be used for classification, were obtained at high stringency from a few genera closely related to Streptococcus. No products were obtained from genomic DNAs from more distantly related genera. Production of species- or strain-specific tRNA intergenic length polymorphisms with primers that generate characteristic products from a variety of species within the same genus should be applicable to many organisms, including those that would otherwise be difficult to culture or identify.
利用聚合酶链反应（PCR），在低严谨度条件下，使用共有tRNA基因引物扩增A、B和G组链球菌菌株的基因间tRNA间隔区。克隆和测序表明，许多同源基因间间隔区在不同物种间长度不同。确定了这些多态性间隔区两侧的tRNA基因序列，并用于合成完全互补的引物。使用这些高严谨度的引物，即使存在1000倍质量过量的人类DNA，也能从链球菌DNA中获得长度在53至71 bp之间变化的PCR产物，具体长度取决于物种或菌株。PCR产物的长度也可用于分类，在高严谨度条件下，从与链球菌密切相关的几个属中也获得了PCR产物。而从亲缘关系较远的属的基因组DNA中未获得产物。使用能从同一属内多种物种产生特征性产物的引物产生物种或菌株特异性的tRNA基因间长度多态性，这应该适用于许多生物体，包括那些否则难以培养或鉴定的生物体。
