The isolation and genetic characterization of extrachromosomal chloramphenicol and oligomycin-resistant mutants from the petite-negative yeast Kluyveromyces lactis

✍ Scribed by Brunner, Aurora ;de Cobos, Alba Tuena ;Griffiths, David E.

• Publisher: Springer
• Year: 1977
• Tongue: English
• Weight: 768 KB
• Volume: 152
• Category: Article
• ISSN: 0026-8925
• DOI: 10.1007/bf00268816

✦ Synopsis

Spontaneous mutants of the petite-negative yeast Kluyveromyces lactis, resistant to the antibiotics chloramphenicol and oligomycin, were isolated and genetically characterized. Three chloramphenicol-resistant mutants showed non-Mendelian inheritance when crossed to sensitive parents. Of 5 oligomycin-resistant strains studied, three exhibited resistance due to the presence of an extrachromosomal mutation. The resistance of the other two deriving from a nuclear and recessive mutation. When two factor crosses in trans configuration were performed between two of the chloramphenicol and the five oligomycin-resistant mutants a polarity in recombination was observed with a predominance of sensitive (OSCS) over resistant (ORCR) reciprocal recombinants. Allelism tests carried out among the oligomycin-resistant mutants indicated the presence of at least two distinct extrachromosomal regions responsible for the resistance.