High-frequency deletion involving closely spaced rRNA gene sets in Streptococcus thermophilus |
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Authors: | Mireille Pébay Yvonne Roussel Jean-Marc Simonet Bernard Decaris |
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Institution: | Laboratoire de Génétique et Microbiologie, Universitéde Nancy I, Facultédes Sciences, Vandœuvre-lès-Nancy, France |
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Abstract: | Abstract 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 independant mutants with five rrn loci were obtained. The deletion frequency was 5 × 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. |
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Keywords: | Streptococcus thermophilus rrn Locus Genetic instability Deletion |
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