Schizosaccharomyces pombe
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PROVIDER: PRJNA215703 | ENA |
REPOSITORIES: ENA
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Project description:Crossovers formed by recombination between homologous chromosomes are important for proper homolog segregation during meiosis and for generation of genetic diversity. Optimal molecular analysis of DNA intermediates of recombination requires synchronous cultures. We previously described a mutant, pat1-as2, of the fission yeast Schizosaccharomyces pombe that undergoes synchronous meiosis at 25°C when an ATP analog is added to the culture. Here, we compare recombination intermediates in pat1-as2 at 25°C with those in the widely used pat1-114 temperature-sensitive mutant at 34°C, a temperature higher than optimal. DNA double-strand breaks at most hotspots are similarly abundant in the two conditions but, remarkably, a few hotspots are distinctly deficient at 25°C. In both conditions Holliday junctions at DNA break hotspots form more frequently between sister chromatids than between homologs, but a novel species, perhaps arising from invasion by only one end of broken DNA, is more readily observed at 25°C. Our results confirm the validity of previous assays of recombination intermediates in S. pombe and provide new information on the mechanism of meiotic recombination.
2013-09-20 | GSE49961 | GEO
Project description:Crossovers formed by recombination between homologous chromosomes are important for proper homolog segregation during meiosis and for generation of genetic diversity. Optimal molecular analysis of DNA intermediates of recombination requires synchronous cultures. We previously described a mutant, pat1-as2, of the fission yeast Schizosaccharomyces pombe that undergoes synchronous meiosis at 25°C when an ATP analog is added to the culture. Here, we compare recombination intermediates in pat1-as2 at 25°C with those in the widely used pat1-114 temperature-sensitive mutant at 34°C, a temperature higher than optimal. DNA double-strand breaks at most hotspots are similarly abundant in the two conditions but, remarkably, a few hotspots are distinctly deficient at 25°C. In both conditions Holliday junctions at DNA break hotspots form more frequently between sister chromatids than between homologs, but a novel species, perhaps arising from invasion by only one end of broken DNA, is more readily observed at 25°C. Our results confirm the validity of previous assays of recombination intermediates in S. pombe and provide new information on the mechanism of meiotic recombination. DNA double-strand break analysis by immunoprecipation of Rec12-FLAG covalently linked to DNA (without exogenous crosslinking agent used) following meiotic induction via pat1-114 or pat1-as2 alleles
2013-09-20 | E-GEOD-49961 | biostudies-arrayexpress
Project description:In eukaryotes, chromosomal DNA is equally distributed to daughter cells during mitosis, whereas the number of chromosomes is halved during meiosis. Despite considerable progress in understanding the molecular mechanisms that regulate mitosis, there is currently a lack of complete understanding of the molecular mechanisms regulating meiosis. Here, we took advantage of the fission yeast Schizosaccharomyces pombe, for which highly synchronous meiosis can be induced, and performed quantitative proteomics and phosphoproteomics analyses to track changes in protein expression and phosphorylation during meiotic cell divisions. We compared the proteomes and phosphoproteomes of mitotic cells with cells harvested around meiosis I, or meiosis II in strains bearing either the temperature-sensitive pat1-114 allele or conditional ATP analog-sensitive pat1-as2 allele of the Pat1 kinase. Comparing pat1-114 with pat1-as2 also allowed us to investigate the impact of elevated temperature (25°C versus 34°C) on meiosis, an issue that sexually reproducing organisms face due to climate change. Using TMTpro 18plex labeling and phosphopeptide enrichment strategies, we performed quantification of a total of 4673 proteins and 7172 phosphosites in S. pombe. We found that the protein level of 2680 proteins and the rate of phosphorylation of 4005 phosphosites significantly changed during progression of S. pombe cells through meiosis. The proteins exhibiting changes in expression and phosphorylation during meiotic cell divisions were represented mainly by those involved in the meiotic cell cycle, meiotic recombination, meiotic nuclear division, meiosis I, centromere clustering, microtubule cytoskeleton organization, ascospore formation, organonitrogen compound biosynthetic process, carboxylic acid metabolic process, gene expression, and ncRNA processing, among others. In summary, our findings provide global overview of changes in the levels and phosphorylation of proteins during progression of S. pombe cells through meiosis at normal and elevated temperatures, laying the groundwork for further elucidation of the functions and importance of specific proteins and their phosphorylation in regulating meiotic cell divisions in this yeast.
2024-10-09 | PXD053920 | Pride
Project description:Homologous recombination events during meiosis cluster at specific loci called hotspots. Hotspot activation requires accessible chromatin, DNA sequence motifs DNA sequence-specific binding proteins, but how these proteins create a suitable environment for Rec12 recruitment is unknown. Here, we purified the ade6-M26 meiotic recombination hotspot from Schizosaccharomyces pombe and identified novel regulators of hotspot activation by mass spectrometry. Small, circular minichromosomes containing the ade6-M26 hotspot or control allele were transformed into strains permitting synchronous meiotic induction and purified from these cultures at sequential time points. Enrichment of known M26 binding factors Atf1 and Pcr1 in the data set validated the approach. Filtering for chromatin-related proteins enriched in the hotspot revealed candidate hotspot regulators, which were validated using genetic studies. This study highlights the power of unbiased proteomic screens to reveal novel insights into fundamental biological processes, and highlights a critical role in H2AZ turnover in mediating access of transcription factors to their underlying DNA-sequence motifs.
2018-11-04 | PXD009649 | Pride
Project description:Meiotic recombination facilitates accurate pairing and faithful segregation of homologous chromosomes by forming physical connections (crossovers) between homologs. Developmentally programmed DNA double-strand breaks (DSBs) generated by Spo11 protein (Rec12 in fission yeast) initiate meiotic recombination. Until recently, attempts to address the basis of the highly non-random distribution of DSBs on a genome-wide scale have been limited to 0.1–1 kb resolution of DSB position. We have assessed individual DSB events across the Schizosaccharomyces pombe genome at near-nucleotide resolution by deep-sequencing the short oligonucleotides connected to Rec12 following DNA cleavage. The single oligonucleotide size-class generated by Rec12 allowed us to effectively analyze all break events. Our high-resolution DSB map shows that the influence of underlying nucleotide sequence and chromosomal architecture differs in multiple ways from that in budding yeast. Rec12 action is not strongly restricted to nucleosome-depleted regions but is nevertheless spatially biased with respect to chromatin structure. Furthermore, we find strong evidence across the genome for differential DSB repair previously predicted to account for crossover invariance (constant cM/kb in spite of DSB hotspots). Our genome-wide analyses demonstrate evolutionarily fluid factors contributing to crossover initiation and its regulation.
2014-06-25 | GSE49977 | GEO
Project description:fission yeast meiotic drive recombination mapping
| PRJNA376152 | ENA
Project description:Meiotic recombination facilitates accurate pairing and faithful segregation of homologous chromosomes by forming physical connections (crossovers) between homologs. Developmentally programmed DNA double-strand breaks (DSBs) generated by Spo11 protein (Rec12 in fission yeast) initiate meiotic recombination. Until recently, attempts to address the basis of the highly non-random distribution of DSBs on a genome-wide scale have been limited to 0.1M-bM-^@M-^S1 kb resolution of DSB position. We have assessed individual DSB events across the Schizosaccharomyces pombe genome at near-nucleotide resolution by deep-sequencing the short oligonucleotides connected to Rec12 following DNA cleavage. The single oligonucleotide size-class generated by Rec12 allowed us to effectively analyze all break events. Our high-resolution DSB map shows that the influence of underlying nucleotide sequence and chromosomal architecture differs in multiple ways from that in budding yeast. Rec12 action is not strongly restricted to nucleosome-depleted regions but is nevertheless spatially biased with respect to chromatin structure. Furthermore, we find strong evidence across the genome for differential DSB repair previously predicted to account for crossover invariance (constant cM/kb in spite of DSB hotspots). Our genome-wide analyses demonstrate evolutionarily fluid factors contributing to crossover initiation and its regulation. Three samples total: one sample sequenced by 454 and two technical replicates (independent adaptor ligations from material purified from one culture) sequenced by SOLiD
2013-08-20 | E-GEOD-49977 | biostudies-arrayexpress
Project description:Mononucleosomal DNA analysis of atf1D and pcr1D mutants of Schizosaccharomyces pombe and transcription analysis of exponential wild type 972 h-, atf1D, pcr1D and mitotic diploid pat1.114, and synchronous diploid pat1.114 at 0h, 3h and 5h into meiosis
2013-11-25 | GSE41770 | GEO
Project description:Mononucleosomal DNA analysis of atf1D and pcr1D mutants of Schizosaccharomyces pombe and transcription analysis of exponential wild type 972 h-, atf1D, pcr1D and mitotic diploid pat1.114, and synchronous diploid pat1.114 at 0h, 3h and 5h into meiosis Mononucleosomal DNA vs. genomic input DNA in wildtype 972 h-, atf1D and pcr1D mutants of S. pombe was hybridized to Affymetrix GeneChip 1.0FR tiling microarrays (GPL7715). Total RNA for genome-wide transcription analysis from exponential wild type 972 h-, atf1D, pcr1D and mitotic diploid pat1.114 cells, and from synchronous diploid pat1.114 at 0h, 3h and 5h into meiosis was hybridized to the same microarrays.
2013-11-25 | E-GEOD-41770 | biostudies-arrayexpress
Project description:The histone variant H2A.Z promotes initiation of meiotic recombination (ChIP)
| PRJNA322525 | ENA