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ABSTRACT:
PROVIDER: PRJNA1110635 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:DNA cytosine methylation suppresses meiotic recombination at the sex-determining region
| PRJNA1029152 | ENA
Project description:DNA cytosine methylation suppresses meiotic recombination at the sex-determining region (Bisulfite-Seq)
| PRJNA1029157 | ENA
Project description:DNA cytosine methylation suppresses meiotic recombination at the sex-determining region (ChiP-Seq)
| PRJNA1029155 | ENA
Project description:DNA cytosine methylation suppresses meiotic recombination at the sex-determining region (RNA-Seq)
| PRJNA1029156 | ENA
Project description:In sexual organisms, random meiotic recombination between homologous chromosomes is vital to maximize genetic variation among offspring. The sex-determining region (SDR), however, does not undergo recombination, as required for the maintenance of distinct alleles. The contribution of epigenetic versus genetic mechanisms to suppress recombination in SDRs and how the suppression mechanisms evolve remain poorly understood. Here we describe the mechanistic control of meiotic recombination at the mating-type locus (MT) in the green alga Chlamydomonas reinhardtii. We identify a maintenance DNA methyltransferase, DNMT1, mutation of which leads to the depletion of 95% of 5-methylcytosines (5mCs) in the nuclear genome. While the 5mC deficiency causes no discernible alteration in haploid vegetative growth or sexual differentiation, the dnmt1 homozygotes display substantially reduced spore viability and 4-progeny-tetrad frequency. Strikingly, in dnmt1 homozygotes, anomalous meiotic recombination takes place at MT, generating haploid progenies with mixed mating-type harboring both plus and minus markers. Although the repressive histone methylation H3K9me1 at MT is lost concurrently in dnmt1 strains, loss of histone methylation alone by gene deletion of the responsible histone methyltransferase SET3p does not lead to anomalous recombination at MT. Thus, DNA methylation, rather than histone modification, mediates the recombination suppression at MT in C. reinhardtii. This finding suggests that in early eukaryotes, which likely lacked histone-based chromatin modification, DNA methylation may have been co-opted to suppress meiotic recombination between alleles responsible for separate sexes.
2024-08-20 | GSE245611 | GEO
Project description:In sexual organisms, random meiotic recombination between homologous chromosomes is vital to maximize genetic variation among offspring. The sex-determining region (SDR), however, does not undergo recombination, as required for the maintenance of distinct alleles. The contribution of epigenetic versus genetic mechanisms to suppress recombination in SDRs and how the suppression mechanisms evolve remain poorly understood. Here we describe the mechanistic control of meiotic recombination at the mating-type locus (MT) in the green alga Chlamydomonas reinhardtii. We identify a maintenance DNA methyltransferase, DNMT1, mutation of which leads to the depletion of 95% of 5-methylcytosines (5mCs) in the nuclear genome. While the 5mC deficiency causes no discernible alteration in haploid vegetative growth or sexual differentiation, the dnmt1 homozygotes display substantially reduced spore viability and 4-progeny-tetrad frequency. Strikingly, in dnmt1 homozygotes, anomalous meiotic recombination takes place at MT, generating haploid progenies with mixed mating-type harboring both plus and minus markers. Although the repressive histone methylation H3K9me1 at MT is lost concurrently in dnmt1 strains, loss of histone methylation alone by gene deletion of the responsible histone methyltransferase SET3p does not lead to anomalous recombination at MT. Thus, DNA methylation, rather than histone modification, mediates the recombination suppression at MT in C. reinhardtii. This finding suggests that in early eukaryotes, which likely lacked histone-based chromatin modification, DNA methylation may have been co-opted to suppress meiotic recombination between alleles responsible for separate sexes.
2024-08-20 | GSE245612 | GEO
Project description:In sexual organisms, random meiotic recombination between homologous chromosomes is vital to maximize genetic variation among offspring. The sex-determining region (SDR), however, does not undergo recombination, as required for the maintenance of distinct alleles. The contribution of epigenetic versus genetic mechanisms to suppress recombination in SDRs and how the suppression mechanisms evolve remain poorly understood. Here we describe the mechanistic control of meiotic recombination at the mating-type locus (MT) in the green alga Chlamydomonas reinhardtii. We identify a maintenance DNA methyltransferase, DNMT1, mutation of which leads to the depletion of 95% of 5-methylcytosines (5mCs) in the nuclear genome. While the 5mC deficiency causes no discernible alteration in haploid vegetative growth or sexual differentiation, the dnmt1 homozygotes display substantially reduced spore viability and 4-progeny-tetrad frequency. Strikingly, in dnmt1 homozygotes, anomalous meiotic recombination takes place at MT, generating haploid progenies with mixed mating-type harboring both plus and minus markers. Although the repressive histone methylation H3K9me1 at MT is lost concurrently in dnmt1 strains, loss of histone methylation alone by gene deletion of the responsible histone methyltransferase SET3p does not lead to anomalous recombination at MT. Thus, DNA methylation, rather than histone modification, mediates the recombination suppression at MT in C. reinhardtii. This finding suggests that in early eukaryotes, which likely lacked histone-based chromatin modification, DNA methylation may have been co-opted to suppress meiotic recombination between alleles responsible for separate sexes.
2024-08-20 | GSE245613 | GEO
Project description:Meiotic recombination differs between males and females, however, when and how these differences are established is unknown. We identify extensive sex differences at recombination initiation by mapping hotspots of meiotic DNA double strand breaks in male and female mice. Contrary to past findings in humans, few hotspots are used uniquely in either sex. Instead, grossly different recombination landscapes result from up to 15-fold differences in hotspot use between males and females. Indeed, most recombination occurs at sex-biased hotspots. Sex biased hotspots appear to be partly determined by chromosome structure, and DNA methylation, absent in females at the onset of meiosis, plays a substantial role. Sex differences are also evident later in meiosis as the repair frequency of distal meiotic breaks as crossovers diverges in males and females. Suppression of distal crossovers may help to minimize age-related aneuploidy that arises due to cohesion loss during dictyate arrest in females.
2018-09-20 | GSE99921 | GEO
Project description:Homologous recombination is the key process that generates genetic diversity and drives evolution. SPO11 protein triggers recombination by introducing DNA double stranded breaks at discreet areas of the genome called recombination hotspots. The hotspot locations are largely determined by the DNA binding specificity of the PRDM9 protein in human, mice and most other mammals. In budding yeast Saccharomyces cerevisae, which lacks a Prdm9 gene, meiotic breaks are formed opportunistically in the regions of accessible chromatin, primarily at gene promoters. The genome-wide distribution of hotspots in this organism can be altered by tethering Spo11 protein to Gal4 recognition sequences in the strain expressing Spo11 attached to the DNA binding domain of the Gal4 transcription factor. To establish whether similar re-targeting of meiotic breaks can be achieved in PRDM9-containing organisms we have generated a Gal4BD-Spo11 mouse that expresses SPO11 protein joined to the DNA binding domain of yeast Gal4. We have mapped the genome-wide distribution of the recombination initiation sites in the Gal4BD-Spo11 mice. More than two hundred of the hotspots in these mice were novel and were likely defined by Gal4BD, as the Gal4 consensus motif was clustered around the centers in these hotspots. Surprisingly, meiotic DNA breaks in the Gal4BD-Spo11 mice were significantly depleted near the ends of chromosomes. The effect is particularly striking at the pseudoautosomal region of the X and Y chromosomes – normally the hottest region in the genome. Our data suggest that specific, yet-unidentified factors influence the initiation of meiotic recombination at subtelomeric chromosomal regions. Detection of meiotic double strand breaks in mice with a hypomorphic Spo11 allele.
2013-09-11 | E-GEOD-48493 | biostudies-arrayexpress
Project description:Homologous recombination is the key process that generates genetic diversity and drives evolution. SPO11 protein triggers recombination by introducing DNA double stranded breaks at discreet areas of the genome called recombination hotspots. The hotspot locations are largely determined by the DNA binding specificity of the PRDM9 protein in human, mice and most other mammals. In budding yeast Saccharomyces cerevisae, which lacks a Prdm9 gene, meiotic breaks are formed opportunistically in the regions of accessible chromatin, primarily at gene promoters. The genome-wide distribution of hotspots in this organism can be altered by tethering Spo11 protein to Gal4 recognition sequences in the strain expressing Spo11 attached to the DNA binding domain of the Gal4 transcription factor. To establish whether similar re-targeting of meiotic breaks can be achieved in PRDM9-containing organisms we have generated a Gal4BD-Spo11 mouse that expresses SPO11 protein joined to the DNA binding domain of yeast Gal4. We have mapped the genome-wide distribution of the recombination initiation sites in the Gal4BD-Spo11 mice. More than two hundred of the hotspots in these mice were novel and were likely defined by Gal4BD, as the Gal4 consensus motif was clustered around the centers in these hotspots. Surprisingly, meiotic DNA breaks in the Gal4BD-Spo11 mice were significantly depleted near the ends of chromosomes. The effect is particularly striking at the pseudoautosomal region of the X and Y chromosomes – normally the hottest region in the genome. Our data suggest that specific, yet-unidentified factors influence the initiation of meiotic recombination at subtelomeric chromosomal regions.
2013-09-11 | GSE48493 | GEO