Ribosomal ribonucleic acid (rRNA) genes were isolated from a digest of chromosomal deoxyribonucleic acid (DNA), cloned in , and used as probes for conserved gene sequences. Recombinant plasmid pHF1 contained an 8,800-base pair insertion containing 5S, 16S, and 23S rRNA genes. We constructed subclones of pHF1 containing parts of the 16S and 23S rRNA genes (pHF1.1) and parts of the 23S and 5S rRNA genes (pHF1.2). DNA-DNA hybridization experiments in which we used filter-bound chromosomal DNA from various bacteria and S-labeled plasmid rRNA genes (rDNA) indicated that the homology values reflected the actual phylogenetic distances to Compared with oligonucleotide sequence analysis of 16S rRNA, a good correlation was found between DNA-rDNA homology values and S (similarity coefficient of 16S rRNAs) values above 0.4. The use of rDNA instead of rRNA in hybridization experiments offers several advantages; e.g., rDNA can easily be labeled in vitro, and the degree of relatedness can be expressed in terms of percent homolgy and does not have to be determined by laborious measurement of thermal stability, as in the case of rRNA.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error