SEQUENCE DIVERSITY OF A GENE ENCODING A PUTATIVE PRIMARY SIGMA-FACTORAMONG BORRELIA-BURGDORFERI SENSU-LATO STRAINS

Twenty-six strains of Borrelia burgdorferi sensu late were subjected t o polymerase chain reaction (PCR)-based restriction fragment length po lymorphism (RFLP) analysis for assessing the sequence divergence of rp oD gene encoding the primary sigma factor. Four and five RFLP patterns were observed from two fragments of rpoD gene. Sequence analysis of a subgenic fragment covering region 1 through 4 from 13 strains of Borr elia burgdorferi s. 1. revealed that 21 of 450 deduced amino acid resi dues were diverged. These results indicate that the sequence heterogen eity of rpoD is present in different strains of Borrelia burgdorferi s . 1., and agreed well with the current classification of genospecies.