Structure of cloned ribosomal DNA cistrons from Bacillus thuringiensis.

A library of B. thuringiensis DNA has been prepared by using the plasmid pBR322 as a cloning vehicle and E. coli as a host cell. By screening this collection with specific probes, 17 clones were identified whose hybrid plasmids contain rRNA genes of B. thuringiensis. Several of these plasmids have been mapped with restriction endonucleases and by DNA-RNA hybridization. By using maps of overlapping fragments, we have been able to establish an overall map of the ribosomal gene cluster.