The primary structure of the 16SrRNA of Mycobacterium leprae: its use in phylogeny and development of DNA probes.

Two long stretches of the 16S from Mycobacterium leprae were sequenced using reverses transcriptase and the chain termination technique. Homology values were calculated for 11 cultivable mycobacteria and a phylogenetic tree constructed from evolutionary distance values (Knuc). Slow and fast growing mycobacteria used in this study form a taxonomic unit but were phylogenetically well separated. It could be confirmed that M. leprae is a true member of the slowly growing pathogenic mycobacteria branching off intermediate to other members of this subgroup. Comparison of the 16 rRNA primary structures reveals that the nucleotide sequence of M. leprae contains regions of sufficient variation to serve as potential target sites for DNA probes. Here we describe the designation of a DNA oligonucleotide and its use in dot blot hybridization experiments were it was directed against bulk RNA isolated from several mycobacteria.