- International Journal of Systematic and Evolutionary Microbiology
- Volume 48, Issue 3
f Structure and genetic stability of mitochondrial genomes vary among yeasts of the genus Saccharomyces
- Authors: Jure Piškur, Sonja Smole†, Casper Groth, Randi F. Petersen, Mogens B. Pedersen
- Author for correspondence: Jure Piškur. Tel: +45 45 252518. Fax: +45 45 932809. e-mail: email@example.com
- Int J Syst Evol Microbiol, July 1998 48: 1015-1024, doi: 10.1099/00207713-48-3-1015
- Subject: Systematics Of Yeasts
- Published Online:
Several yeast species/isolates belonging to the genus Saccharomyces were examined for the organization of their mtDNAs and ability to generate petite mutants. A general characteristic for all of the mtDNAs tested was that they were very A+T-rich. However, restriction patterns and inducibility of petite mutations revealed a great diversity in the organization and genetic behaviour of mtDNAs. One group of yeasts, Saccharomyces sensu stricto, contains mtDNA ranging in size from 64 to 85 kb. mtDNAs from these yeasts contain a high number of restriction sites that are recognized by the enzymes Haelll and Mspl, which cut specifically in G+C clusters. There are three to nine ori/rep sequences per genome. These yeasts spontaneously generate respiration deficient mutants. Ethidium bromide (Et-Br), at low concentrations, induces a majority of cells to give rise to petites. A second group of yeasts, Saccharomyces sensu lato, contains smaller mtDNAs, ranging in size from 23 to 48 kb, and probably only a few intergenic G+C clusters and no ori/rep sequences. These yeasts also generate petite clones spontaneously, but Et-Br, even when present at high concentrations, does not substantially increase the frequency of petites. In most petite clones from these yeasts only a small fragment of the wild-type molecule is retained and apparently multiplied. A third group, represented by Saccharomyces kluyveri, does not give rise to petite mutants either spontaneously or after induction.
Present address: Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia.
© 1998, International Union of Microbiological Societies | Published by the International Union of Microbiological Societies
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