High-frequency deletion involving closely spaced rRNA gene sets in Streptococcus thermophilus
1992
Pebay, M. | Roussel, Y. | Simonet, J.M. | Decaris, B.
Homologous rDNA probes were used to study the number of rRNA genes in a five-generation genealogy of Streptococcus thermophilus CNRZ368. Whereas the CNRZ368 strain contained six rRNA loci, four independent mutants with five rrn loci were obtained. The deletion frequency was 5 X 10(-2). Molecular analysis provided identical hybridization patterns for all the deletion mutants. The deletion was shown to occur within the two close rRNA loci, rrnD and rrnE, probably due to a homologous recombination event and to give rise to a hybrid rrnD/E locus.
显示更多 [+] 显示较少 [-]