Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2000-8-11
pubmed:abstractText
The 5'-3' exonuclease Exo1p from Saccharomyces cerevisiae is required for wild-type levels of meiotic crossing-over and normal meiotic chromosome segregation as is the meiosis-specific MutS homologue, Msh4p. Mutations in both genes reduce crossing-over by approximately two-fold, but deltamsh4 strains have significantly lower viability and a higher frequency of meiosis I non-disjunction. Epistasis analysis indicates a complex interaction between the two genes. Although crossing-over was not detectably lower in the double mutant, viability was significantly worse than either single mutant. Such a result suggests that the two genes are affecting meiotic viability by distinct mechanisms. We propose that deltaexo1 affects chromosome segregation by reducing crossing-over, while deltamsh4 affects both the frequency and distribution of crossovers. Mutation in EXO1 reduces gene conversion frequencies significantly at some but not all loci, suggesting that other enzymes are also involved in DNA resection. We propose that Exo1p plays an early role in establishing some recombination intermediates by generating single-stranded tails. The role of Msh4p is suggested to be in determining whether some recombination intermediates are resolved as crossover events and in generating crossover interference. The synergistic effect of deltaexo1deltamsh4 on spore viability suggests that the two genes have partially compensatory roles in a process affecting meiotic success.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0009-5915
pubmed:author
pubmed:issnType
Print
pubmed:volume
109
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
94-102
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
EXO1 and MSH4 differentially affect crossing-over and segregation.
pubmed:affiliation
Department of Biochemistry, University of Oxford, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't