scholarly journals ABNORMAL MITOCHONDRIAL GENOMES IN YEAST RESTORED TO RESPIRATORY COMPETENCE

Genetics ◽  
1978 ◽  
Vol 90 (3) ◽  
pp. 517-530
Author(s):  
K M Oakley ◽  
G D Clark-Walker
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Hot Spots ◽  
High Frequency ◽  
Mitochondrial Genomes ◽  
Dna Fragments ◽  
Petite Mutants ◽  
Large Numbers

ABSTRACT When crosses are performed between newly arisen, spontaneous petite mutants of Saccharomyces cerevisiae, respiratory competent (restored) colonies can form. Some of the restored colonies are highly sectored and produce large numbers of petite mutants. The high-frequency petite formation trait is inherited in a non-Mendelian manner, and elimination of mitochondrial DNA from these strains results in the loss of the trait. These results indicate that abnormal mitochondrial genomes are sometimes formed during restoration of respiratory competence. It is hypothesized that these abnormalities result either from recombination between mitochondrial DNA fragments to produce molecules having partial duplications contained on inverted or transposed sequences, or else recombinational "hot spots" have been expanded.

scholarly journals Mitochondrial DNA duplication, recombination, and introgression during interspecific hybridization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Silvia Bágeľová Poláková ◽  
Žaneta Lichtner ◽  
Tomáš Szemes ◽  
Martina Smolejová ◽  
Pavol Sulo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Interspecific Hybridization ◽  
Mobile Elements ◽  
Variable Length ◽  
Mitochondrial Genomes ◽  
Free Standing ◽  
Saccharomyces Paradoxus ◽  
Mtdna Recombination

AbstractmtDNA recombination events in yeasts are known, but altered mitochondrial genomes were not completed. Therefore, we analyzed recombined mtDNAs in six Saccharomyces cerevisiae × Saccharomyces paradoxus hybrids in detail. Assembled molecules contain mostly segments with variable length introgressed to other mtDNA. All recombination sites are in the vicinity of the mobile elements, introns in cox1, cob genes and free standing ORF1, ORF4. The transplaced regions involve co-converted proximal exon regions. Thus, these selfish elements are beneficial to the host if the mother molecule is challenged with another molecule for transmission to the progeny. They trigger mtDNA recombination ensuring the transfer of adjacent regions, into the progeny of recombinant molecules. The recombination of the large segments may result in mitotically stable duplication of several genes.

Mitochondrial DNA and suppressiveness of petite mutants in Saccharomyces cerevisiae

1971 ◽  
Vol 5 (5) ◽  
pp. 487-495 ◽  
Author(s):  
Georg Michaelis ◽  
Stephen Douglass ◽  
Ming-Jer Tsai ◽  
Richard S. Criddle
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Petite Mutants

scholarly journals ELEVATED LEVELS OF PETITE FORMATION IN STRAINS OF SACCHAROMYCES CEREVISIAE RESTORED TO RESPIRATORY COMPETENCE. I. ASSOCIATION OF BOTH HIGH AND MODERATE FREQUENCIES OF PETITE MUTANT FORMATION WITH THE PRESENCE OF ABERRANT MITOCHONDRIAL DNA

Genetics ◽  
1985 ◽  
Vol 111 (3) ◽  
pp. 389-402
Author(s):  
R J Evans ◽  
K M Oakley ◽  
G D Clark-Walker
Keyword(s):  
Saccharomyces Cerevisiae ◽  
High Frequency ◽  
Restriction Endonuclease Analysis ◽  
Heterogeneous Population ◽  
Mitochondrial Genomes ◽  
Fragmentation Pattern ◽  
Wild Type ◽  
Petite Mutant ◽  
Apparent Correlation ◽  
Endonuclease Analysis

ABSTRACT When recently arisen spontaneous petite mutants of Saccharomyces cerevisiae are crossed, respiratory competent diploids can be recovered. Such restored strains can be divided into two groups having sectored or unsectored colony morphology, the former being due to an elevated level of spontaneous petite mutation. On the basis of petite frequency, the sectored strains can be subdivided into those with a moderate frequency (5-16%) and those with a high frequency (>60%) of petite formation. Each of the three categories of restored strains can be found on crossing two petites, suggesting either that the parental mutants contain a heterogeneous population of deleted mtDNAs at the time of mating or that different interactions can occur between the defective molecules. Restriction endonuclease analysis of mtDNA from restored strains that have a wild-type petite frequency showed that they had recovered a wild-type mtDNA fragmentation pattern. Conversely, all examined cultures from both categories of sectored strains contained aberrant mitochondrial genomes that were perpetuated without change over at least 200 generations. In addition, sectored colony siblings can have different aberrant mtDNAs. The finding that two sectored, restored strains from different crosses have identical but aberrant mtDNAs provides evidence for preferred deletion sites from the mitochondrial genome. Although it appears that mtDNAs from sectored strains invariably contain duplications, there is no apparent correlation between the size of the duplication and spontaneous petite frequency.

scholarly journals Relative retention of mitochondrial markers in petite mutants: mitochondrially determined differences betweenRHO(+) strains

1975 ◽  
Vol 26 (3) ◽  
pp. 319-325 ◽  
Author(s):  
P. L. Molloy ◽  
Anthony W. Linnane ◽  
H. B. Lukins
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Uv Irradiation ◽  
Relative Frequency ◽  
The Other ◽  
Mitochondrial Genomes ◽  
Marked Variation ◽  
Mitochondrial Markers ◽  
Relative Retention ◽  
Petite Mutants ◽  
Structural Differences

SUMMARYThe relative frequency of retention of two mitochondrial loci, determining resistance to oligomycin (oli1) and erythromycin (ery1), has been analysed in petite (rho(−)) mutants derived from a number of unrelated strains ofSaccharomyces cerevisiae. The frequency of retention of one marker relative to the other in spontaneous petites showed marked variation dependent on the strain of origin. The differences between strains in this characteristic were shown to be mitochondrially determined. Further, for individual strains, the relative retention of the markers in petites derived after UV-irradiation varied considerably in several cases from that observed with spontaneous petites. The observations on relative marker retention and the varied effects of UV-irradiation are discussed in terms of possible structural differences in the mitochondrial genomes of the various strains.

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