Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1263794 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR33610600_1.fastq.gz | Fastqsanger.gz | |||
| SRR33610600_2.fastq.gz | Fastqsanger.gz | |||
| SRR33610601_1.fastq.gz | Fastqsanger.gz | |||
| SRR33610601_2.fastq.gz | Fastqsanger.gz | |||
| SRR33610602_1.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 5 of 120 |
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Project description:Intraindividual rDNA copy number variation and methylation in humans
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Project description:The absolute number of rDNA transcription units can vary by about one power of ten among individuals. Apart from extensive rDNA copy number (CN) variation and instability in many cancers, there is little information on the extent of intraindividual CN variation between normal s. Here we used droplet digital PCR and deep bisulfite sequencing to determine both the absolute rDNA CN and the number of presumably active CN with a hypomethylated (0-10%) promoter region in up to six different s of 13 autopsy probands. In general, the absolute rDNA CN as well as the frequency of the minor A variant were highly similar between s (cerebellum, cerebrum, colon, heart, intestine, kidney, and liver liver and spleen) of the same individual. However, in some probands absolute CN in one or multiple s was much higher than in the other s., consistent with relaxation/breakdown of the CN control system. The amplified copies were inactivated by promoter methylation and, thus, the number of active CN was largely independent from absolute CN. Collectively, our data suggest that with some notable exceptions absolute and even more active rDNA CN are maintained during development and differentiation in different s of the same individual. Despite the low intraindividual variation active CN appeared to systematically vary between s. Cerebellum, which is characterized by the highest density of non-dividing neuronal cells in the body, consistently exhibited lower active CN than other s. We estimate that a minimum number of > 50 active rDNA TU is required for normal /organ function.
2025-06-16 | GSE297209 | GEO
Project description:Please see publication. These experiments were performed to ascertain the contribution of Y-linked rDNA copy number variation in the modulation of gene expression. Males (XY) and female (XXY) genotypes were probed.
2011-08-01 | GSE27695 | GEO
Project description:Ribosome is the most abundant RNA-protein complex in a cell and many copies of the ribosomal RNA gene (rDNA) have to be maintained. However, arrays of tandemly repeated rDNA genes can lose the copies by intra-repeat recombination. Loss of the rDNA copies of Saccharomyces cerevisiae is counteracted by gene amplification whereby the number of rDNA repeats stabilizes around 150 copies, suggesting the presence of a monitoring mechanism that counts and adjusts the number. Here, we report that in response to rDNA copy loss, the upstream activating factor (UAF) for RNA polymerase I which transcribes the rDNA is released and directly bind to a RNA polymerase II transcribed gene, SIR2 to repress, whose gene products silence rDNA recombination. We show that the amount of UAF determines rDNA copies number that is stably maintained. UAF ensures rDNA production not only by rDNA transcription activation but also by its copy number maintenance.
2019-01-03 | GSE116661 | GEO
Project description:Ribosomal DNA (rDNA) is organized as large arrays of tandem repeats that vary in copy number from a few dozen to hundreds. In the budding yeast Saccharomyces cerevisiae, each rDNA repeat includes a potential origin of replication. Previous work has led to the model that the rDNA replication origins compete for limiting replication initiation factors with origins in the rest of the genome, suggesting that reduction in rDNA copy number would reduce competition for these limiting factors and therefore promote origin usage in the rest of the genome. To test this hypothesis, we compared genome-wide replication in strains with either wild type rDNA copy number of ~180 (“180 rDNA”) or just ~35 copies (“35 rDNA”) by performing dense-to-light isotope transfer experiments to physically separate replicated, hybrid-density (HL or heavy-light) DNA from unreplicated, HH (heavy-heavy) DNA in cell samples collected at different times in S phase. Contrary to our expectations, we find that although there are no apparent differences in non-rDNA origin activity between the two strains, the 35 rDNA strain shows a genome-wide delay in progression through S phase compared to the 180 rDNA strain.
2023-02-17 | GSE205068 | GEO
Project description:Ribosomal RNA (rRNA) genes exist in multiple copies arranged in tandem arrays known as ribosomal DNA (rDNA). The total number of gene copies is variable, and the mechanisms buffering this copy number variation remain unresolved. We surveyed the number, distribution, and activity of rDNA arrays at the level of individual chromosomes across multiple human and primate genomes. Each individual possessed a unique fingerprint of copy number distribution and activity of rDNA arrays. In some cases, entire rDNA arrays were transcriptionally silent. Silent rDNA arrays showed reduced association with the nucleolus and decreased interchromosomal interactions, indicating that the nucleolar organizer function of rDNA depends on transcriptional activity. Methyl-sequencing of flow-sorted chromosomes, combined with long read sequencing, showed epigenetic modification of rDNA promoter and coding region by DNA methylation. Silent arrays were in a closed chromatin state, as indicated by the accessibility profiles derived from Fiber-seq. Removing DNA methylation restored the transcriptional activity of silent arrays. Array activity status remained stable through the iPS cell re-programming. Family trio analysis demonstrated that the inactive rDNA haplotype can be traced to one of the parental genomes, suggesting that the epigenetic state of rDNA arrays may be heritable. We propose that the dosage of rRNA genes is epigenetically regulated by DNA methylation, and these methylation patterns specify nucleolar organizer function and can propagate transgenerationally.
2025-08-25 | GSE306059 | GEO
Project description:Ribosomal RNA (rRNA) genes exist in multiple copies arranged in tandem arrays known as ribosomal DNA (rDNA). The total number of gene copies is variable, and the mechanisms buffering this copy number variation remain unresolved. We surveyed the number, distribution, and activity of rDNA arrays at the level of individual chromosomes across multiple human and primate genomes. Each individual possessed a unique fingerprint of copy number distribution and activity of rDNA arrays. In some cases, entire rDNA arrays were transcriptionally silent. Silent rDNA arrays showed reduced association with the nucleolus and decreased interchromosomal interactions, indicating that the nucleolar organizer function of rDNA depends on transcriptional activity. Methyl-sequencing of flow-sorted chromosomes, combined with long read sequencing, showed epigenetic modification of rDNA promoter and coding region by DNA methylation. Silent arrays were in a closed chromatin state, as indicated by the accessibility profiles derived from Fiber-seq. Removing DNA methylation restored the transcriptional activity of silent arrays. Array activity status remained stable through the iPS cell re-programming. Family trio analysis demonstrated that the inactive rDNA haplotype can be traced to one of the parental genomes, suggesting that the epigenetic state of rDNA arrays may be heritable. We propose that the dosage of rRNA genes is epigenetically regulated by DNA methylation, and these methylation patterns specify nucleolar organizer function and can propagate transgenerationally.
2025-08-25 | GSE306056 | GEO
Project description:Ribosomal RNA (rRNA) genes exist in multiple copies arranged in tandem arrays known as ribosomal DNA (rDNA). The total number of gene copies is variable, and the mechanisms buffering this copy number variation remain unresolved. We surveyed the number, distribution, and activity of rDNA arrays at the level of individual chromosomes across multiple human and primate genomes. Each individual possessed a unique fingerprint of copy number distribution and activity of rDNA arrays. In some cases, entire rDNA arrays were transcriptionally silent. Silent rDNA arrays showed reduced association with the nucleolus and decreased interchromosomal interactions, indicating that the nucleolar organizer function of rDNA depends on transcriptional activity. Methyl-sequencing of flow-sorted chromosomes, combined with long read sequencing, showed epigenetic modification of rDNA promoter and coding region by DNA methylation. Silent arrays were in a closed chromatin state, as indicated by the accessibility profiles derived from Fiber-seq. Removing DNA methylation restored the transcriptional activity of silent arrays. Array activity status remained stable through the iPS cell re-programming. Family trio analysis demonstrated that the inactive rDNA haplotype can be traced to one of the parental genomes, suggesting that the epigenetic state of rDNA arrays may be heritable. We propose that the dosage of rRNA genes is epigenetically regulated by DNA methylation, and these methylation patterns specify nucleolar organizer function and can propagate transgenerationally.
2025-08-26 | GSE306108 | GEO
Project description:The diet consumed by fathers prior to procreation impacts metabolic phenotypes in their offspring, but the mechanisms underlying such intergenerational information transfer remain obscure. Here, we carried out extensive analysis of cytosine methylation patterns in murine sperm, generating whole genome methylation maps for 4 pools of sperm samples and for 12 individual sperm samples, as well as 61 genome-scale reduced-representation bisulfite sequencing (RRBS) methylation maps, using samples obtained from male mice consuming various diets. We found that epivariation, either stochastic or due to unknown demographic or environmental factors, was a far stronger contributor to the sperm methylome than was the diet consumed. Variation in cytosine methylation was particularly dramatic over tandem repeat families, including ribosomal DNA (rDNA) repeats, and rDNA methylation levels were heritable from one generation to the next. However, rDNA methylation was strongly correlated with genetic variation in rDNA copy number, and analysis of hundreds of sperm samples revealed no consistent effect of diet on rDNA copy number or methylation level in sperm, indicating that paternal diet exerts an rDNA methylation-independent effect on offspring gene expression. These results reveal loci of genetic and epigenetic lability in the mammalian genome, but strongly argue against a direct mechanistic role for sperm cytosine methylation in dietary reprogramming of offspring metabolism.
2015-12-17 | GSE75323 | GEO