RDH54, a RAD54 Homologue in Saccharomyces cerevisiae, Is Required for Mitotic Diploid-Specific Recombination and Repair and for Meiosis

Genetics ◽  
1997 ◽  
Vol 147 (4) ◽  
pp. 1533-1543 ◽  
Author(s):  
Hannah L Klein
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Prolonged Exposure ◽  
Methyl Methanesulfonate ◽  
Spore Viability ◽  
Homologous Chromosomes ◽  
High Concentrations ◽  
Genome Ploidy ◽  
Repair Genes

Abstract Most mitotic recombination and repair genes of Saccharomyces cerevisiae show no specificity of action for the genome ploidy. We describe here a novel repair and recombination gene that is specific for recombination and repair between homologous chromosomes. The RDH54 gene is homologous to the RAD54 gene, but rdh54 mutants do not show sensitivity to methyl methanesulfonate at concentrations that sensitize a rad54 mutant. However, the rdh54 null mutation enhances the methyl methanesulfonate sensitivity of a rad54 mutant and single rdh54 mutants are sensitive to prolonged exposure at high concentrations of methyl methanesulfonate. The RDH54 gene is required for recombination, but only in a diploid. We present evidence showing that the RDH54 gene is required for interhomologue gene conversion but not intrachromosomal gene conversion. The rdh54 mutation confers diploid-specific lethalities and reduced growth in various mutant backgrounds. These phenotypes are due to attempted recombination. The RDH54 gene is also required for meiosis as homozygous mutant diploids show very poor sporulation and reduced spore viability. The role of the RDH54 gene in mitotic repair and in meiosis and the pathway in which it acts are discussed.

Analysis of a gene conversion gradient at the HIS4 locus in Saccharomyces cerevisiae.

Genetics ◽  
1992 ◽  
Vol 132 (1) ◽  
pp. 113-123 ◽  
Author(s):  
P Detloff ◽  
M A White ◽  
T D Petes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Mismatch Repair ◽  
Meiotic Recombination ◽  
Present Evidence ◽  
Homologous Chromosomes ◽  
A Site ◽  
His4 Gene ◽  
Heteroduplex Formation ◽  
Recombination Gene

Abstract Heteroduplexes formed between genes on homologous chromosomes are intermediates in meiotic recombination. In the HIS4 gene of Saccharomyces cerevisiae, most mutant alleles at the 5' end of the gene have a higher rate of meiotic recombination (gene conversion) than mutant alleles at the 3' end of the gene. Such gradients are usually interpreted as indicating a higher frequency of heteroduplex formation at the high conversion end of the gene. We present evidence indicating that the gradient of conversion at HIS4 primarily reflects the direction of mismatch repair rather than the frequency of heteroduplex formation. We also identify a site located between the 5' end of HIS4 and the 3' end of BIK1 that stimulates heteroduplex formation at HIS4 and BIK1.

scholarly journals The role of DNA repair genes in recombination between repeated sequences in yeast.

Genetics ◽  
1995 ◽  
Vol 140 (4) ◽  
pp. 1199-1211
Author(s):  
B Liefshitz ◽  
A Parket ◽  
R Maya ◽  
M Kupiec
Keyword(s):  
Dna Repair ◽  
Gene Conversion ◽  
Genetic Control ◽  
Excision Repair ◽  
Direct Repeat ◽  
Repeated Sequences ◽  
Ty Elements ◽  
Naturally Occurring ◽  
Repair Genes

Abstract The presence of repeated sequences in the genome represents a potential source of karyotypic instability. Genetic control of recombination is thus important to preserve the integrity of the genome. To investigate the genetic control of recombination between repeated sequences, we have created a series of isogenic strains in which we could assess the role of genes involved in DNA repair in two types of recombination: direct repeat recombination and ectopic gene conversion. Naturally occurring (Ty elements) and artificially constructed repeats could be compared in the same cell population. We have found that direct repeat recombination and gene conversion have different genetic requirements. The role of the RAD51, RAD52, RAD54, RAD55, and RAD57 genes, which are involved in recombinational repair, was investigated. Based on the phenotypes of single and double mutants, these genes can be divided into three functional subgroups: one composed of RAD52, a second one composed of RAD51 and RAD54, and a third one that includes the RAD55 and RAD57 genes. Among seven genes involved in excision repair tested, only RAD1 and RAD10 played a role in the types of recombination studied. We did not detect a differential effect of any rad mutation on Ty elements as compared to artificially constructed repeats.

scholarly journals Role of GerKB in Germination and Outgrowth of Clostridium perfringens Spores

2009 ◽  
Vol 75 (11) ◽  
pp. 3813-3817 ◽  
Author(s):  
Daniel Paredes-Sabja ◽  
Peter Setlow ◽  
Mahfuzur R. Sarker
Keyword(s):  
Clostridium Perfringens ◽  
Spore Germination ◽  
Nutrient Concentrations ◽  
Wild Type ◽  
Spore Viability ◽  
Colony Forming Efficiency ◽  
Forming Efficiency ◽  
High Concentrations ◽  
Auxiliary Role

ABSTRACT Previous work indicated that Clostridium perfringens gerKA gerKC spores germinate significantly, suggesting that gerKB also has a role in C. perfringens spore germination. We now find that (i) gerKB was expressed only during sporulation, likely in the forespore; (ii) gerKB spores germinated like wild-type spores with nonnutrient germinants and with high concentrations of nutrients but more slowly with low nutrient concentrations; and (iii) gerKB spores had lower colony-forming efficiency and slower outgrowth than wild-type spores. These results suggest that GerKB plays an auxiliary role in spore germination under some conditions and is required for normal spore viability and outgrowth.

The Involvement of Cellular Recombination and Repair Genes in RNA-Mediated Recombination in Saccharomyces cerevisiae

Genetics ◽  
1998 ◽  
Vol 148 (3) ◽  
pp. 937-945
Author(s):  
Leslie K Derr
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Reporter Gene ◽  
Target Sequence ◽  
Wild Type ◽  
Gene Functions ◽  
Repair Genes ◽  
Insight Into ◽  
Reverse Transcript ◽  
Recombination Gene

Abstract We previously demonstrated that a reverse transcript of a cellular reporter gene (his3-AI) can serve as the donor for gene conversion of a chromosomal his3-ΔMscI target sequence, and that this process requires the yeast recombination gene RAD52. In this study, we examine the involvement of other recombination and repair genes in RNA-mediated recombination, and gain insight into the nature of the recombination intermediate. We find that mutation of the mitotic RecA homologs RAD51, RAD55, and RAD57 increases the rate of RNA-mediated recombination relative to the wild type, and that these gene functions are not required for RNA-mediated gene conversion. Interestingly, RAD1 is required for RNA-mediated gene conversion of chromosomal his3-ΔMscI sequences, suggesting that the cDNA intermediate has a region of nonhomology that must be removed during recombination with target sequences. The observation that both RAD1 and RAD52 are required for RNA-mediated gene conversion of chromosomal but not plasmid sequences indicates a clear difference between these two pathways of homologous RNA-mediated recombination.

scholarly journals Meiotic chromosome pairing in triploid and tetraploid Saccharomyces cerevisiae.

Genetics ◽  
1995 ◽  
Vol 139 (4) ◽  
pp. 1511-1520 ◽  
Author(s):  
J Loidl
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Complex Formation ◽  
Chromosome Segregation ◽  
Chromosome Pairing ◽  
Meiotic Chromosome ◽  
Low Frequency ◽  
Spore Viability ◽  
Homologous Chromosomes ◽  
Meiotic Chromosome Pairing ◽  
Synaptonemal Complex Formation

Abstract Meiotic chromosome pairing in isogenic triploid and tetraploid strains of yeast and the consequences of polyploidy on meiotic chromosome segregation are studied. Synaptonemal complex formation at pachytene was found to be different in the triploid and in the tetraploid. In the triploid, triple-synapsis, that is, the connection of three homologues at a given site, is common. It can even extend all the way along the chromosomes. In the tetraploid, homologous chromosomes mostly come in pairs of synapsed bivalents. Multiple synapsis, that is, synapsis of more than two homologues in one and the same region, was virtually absent in the tetraploid. About five quadrivalents per cell occurred due to the switching of pairing partners. From the frequency of pairing partner switches it can be deduced that in most chromosomes synapsis is initiated primarily at one end, occasionally at both ends and rarely at an additional intercalary position. In contrast to a considerably reduced spore viability (approximately 40%) in the triploid, spore viability is only mildly affected in the tetraploid. The good spore viability is presumably due to the low frequency of quadrivalents and to the highly regular 2:2 segregation of the few quadrivalents that do occur. Occasionally, however, quadrivalents appear to be subject to 3:1 nondisjunction that leads to spore death in the second generation.

scholarly journals Mitotic gene conversion tracts associated with repair of a defined double-strand break in Saccharomyces cerevisiae

2017 ◽  
Author(s):  
Yee Fang Hum ◽  
Sue Jinks-Robertson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Homologous Recombination ◽  
Gene Conversion ◽  
Strand Break ◽  
Double Strand Break ◽  
The Other ◽  
Homologous Chromosomes ◽  
Molecular Features ◽  
Single Side ◽  
Mitotic Gene Conversion

AbstractMitotic recombination between homologous chromosomes can lead to loss-of-heterozygosity (LOH), which is an important contributor to human disease. In the current study, a defined double-strand break (DSB) on chromosome IV was used to initiate LOH in a yeast strain with sequence-diverged chromosomes. Associated gene conversion tracts, which reflect the repair of mismatches formed when diverged chromosomes exchange single strands, were mapped using microarrays. LOH events reflected two broken chromosomes, one of which was repaired as a crossover and the other as a noncrossover. Gene conversion tracts associated with individual crossover and noncrossover events were similar in size and position, with half of the tracts unexpectedly mapping to only a single side of the initiating break. Although the molecular features of DSB-initiated events generally agree with those predicted by current models of homologous recombination, there were unexpected complexities in associated gene conversion tracts.

scholarly journals Homolog of Saccharomyces cerevisiae SLX4 is required for cell recovery from MMS-induced DNA damage in Candida albicans

2021 ◽  
Author(s):  
Yueqing Wang ◽  
Na Wang ◽  
Jia Liu ◽  
Yaxuan Zhang ◽  
Xiaojiaoyang Li ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Damage ◽  
Dna Repair ◽  
Candida Albicans ◽  
Methyl Methanesulfonate ◽  
Dna Repair Genes ◽  
Cell Recovery ◽  
Yeast Form ◽  
Increased Sensitivity ◽  
Repair Genes

Abstract SLX4 is a scaffold to coordinate the action of structure-specific endonucleases that are required for homologous recombination and DNA repair. In view of ScSLX4 functions in the maintenance and stability of the genome in Saccharomyces cerevisiae, we have explored the roles of CaSLX4 in Candida albicans. Here, we constructed slx4Δ/Δ mutant and found that it exhibited increased sensitivity to the DNA damaging agent, methyl methanesulfonate (MMS) but not the DNA replication inhibitor, hydroxyurea (HU). Accordingly, RT-qPCR and Western blotting analysis revealed the activation of SLX4 expression in response to MMS. The deletion of SLX4 resulted in a defect in the recovery from MMS-induced filamentation to yeast form and re-entry into the cell cycle. Like many other DNA repair genes, SLX4 expression was activated by the checkpoint kinase Rad53 under MMS-induced DNA damage. In addition, SLX4 was not required for the inactivation of the DNA damage checkpoint, as indicated by normal phosphorylation of Rad53 in slx4Δ/Δ cells. Therefore, our results demonstrate SLX4 plays an important role in cell recovery from MMS-induced DNA damage in C. albicans.

The role of heteroduplex correction in gene conversion in Saccharomyces cerevisiae

Nature ◽  
1987 ◽  
Vol 328 (6128) ◽  
pp. 362-364 ◽  
Author(s):  
Douglas K. Bishop ◽  
Marsha S. Williamson ◽  
Seymour Fogel ◽  
Richard D. Kolodner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion

scholarly journals Coupling crossover and synaptonemal complex in meiosis

2022 ◽  
Vol 36 (1-2) ◽  
pp. 4-6
Author(s):  
Corinne Grey ◽  
Bernard de Massy
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Homologous Recombination ◽  
Synaptonemal Complex ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Dsb Repair ◽  
Strand Breaks ◽  
Homologous Chromosomes

During meiosis, a molecular program induces DNA double-strand breaks (DSBs) and their repair by homologous recombination. DSBs can be repaired with or without crossovers. ZMM proteins promote the repair toward crossover. The sites of DSB repair are also sites where the axes of homologous chromosomes are juxtaposed and stabilized, and where a structure called the synaptonemal complex initiates, providing further regulation of both DSB formation and repair. How crossover formation and synapsis initiation are linked has remained unknown. The study by Pyatnitskaya and colleagues (pp. 53–69) in this issue of Genes & Development highlights the central role of the Saccharomyces cerevisiae ZMM protein Zip4 in this process.

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