Author/Editor     Piškur, Jure
Title     Transmission of the yeast mitochondrial genome to progeny: the impact of intergenic sequences
Type     članek
Source     Mol Gen Genet
Vol. and No.     Letnik 218, št. 1
Publication year     1989
Volume     str. 161-8
Language     eng
Abstract     In a previous publication it was shown that the output of yeast mitochondrial loci lacking nearby intergenic sequences (encompassing ori/rep elements) was reduced in crosses to strains with wild-type mtDNAs. In the present work, mitochondrial genomes carrying the intergenic deletions were marked at unlinked loci by introducing specific antibiotic resistance mutations against erythromycin, oligomycin and paromomycin. These marked genomes were used to follow the output of unlinked regions of the genome from crosses between the intergenic deletion mutants and wild-type strains. Transmission of genetically unlinked markers in coding regions was substantially reduced when an intergenic deletion was present on the same genome. In general the transmission of the antibiotic markers was the same as or slightly higher than the corresponding intergenic marker. These results indicate that the presence of an intergenic deletion in the regions studied impairs the transmission to progeny of a mitochondrial genome as a whole. More specifically, the results suggest that ori/rep sequences, present in the regions that have been deleted, confer a competitive advantage over genomes lacking a full complement of such sequences. These results support the hypothesis that intergenic sequences, and specifically ori/rep elements, have a biological role in the mitochondrial genome. However, because of the exclusive presence of ori/rep sequences in the genus Saccharomyces, it may be that these sequences evolved in (or invaded) the mitochondrial genome relatively late in the evolution of the yeasts. (Abstract truncated at 2000 characters)
Descriptors     EXTRACHROMOSOMAL INHERITANCE
INTRONS
ALLELES
CROSSES, GENETIC
DNA, FUNGAL
DNA, MITOCHONDRIAL
DRUG RESISTANCE, MICROBIAL
GENETIC MARKERS
MUTATION
RECOMBINATION, GENETIC
SACCHAROMYCES CEREVISIAE