Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1055879 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Nanopore long-read sequencing was used to generate a complete assembly of the Arabidopsis centromeres.
2021-04-02 | E-MTAB-10272 | biostudies-arrayexpress
Project description:Accurate chromosome segregation requires centromeres (CENs), the chromosomal sites where kinetochores form, to bridge DNA and attach to microtubules. In contrast to most eukaryotes, Saccharomyces cerevisiae possesses sequence-defined point centromeres. Chromatin immunoprecipitation followed by sequencing (ChIP-Seq) of four kinetochore components reveals regions of overlapping, extra-centromeric protein localization upon overproduction of the centromeric histone, Cse4 (CENP-A or CenH3). These identified sequences enhance proper plasmid and chromosome segregation, and are termed Centromere-like Regions (CLRs). CLRs form in close proximity to S. cerevisiae CENs and share characteristics typical of point and regional centromeres. CLR sequences are conserved among related budding yeasts, suggesting a role in vivo. These studies provide new insights into the origin and evolution of centromeres. ChIP-Seq analysis of the kinetochore components Cse4, Mif2, Ndc10 and Ndc80 in budding yeast strains (Saccharomyces cerevisiae) with normal and elevated levels of Cse4
2013-01-18 | E-GEOD-31466 | biostudies-arrayexpress
Project description:Centromeres are chromosomal regions that serve as platforms for kinetochore assembly and spindle attachments, ensuring accurate chromosome segregation during cell division. Despite functional conservation, centromeric sequences are diverse and usually repetitive across species, making them challenging to assemble and identify. Here, we describe centromeres in the model oomycete Phytophthora sojae by combining long-read sequencing-based genome assembly and chromatin immunoprecipitation for the centromeric histone CENP-A followed by high-throughput sequencing (ChIP-seq). P. sojae centromeres cluster at a single focus in the nucleus at different life stages and during nuclear division. We report a highly contiguous genome assembly of the P. sojae reference strain, which enabled identification of 15 highly enriched CENP-A binding regions as putative centromeres. By focusing on 10 intact regions, we demonstrate that centromeres in P. sojae are regional, spanning 211 to 356 kb. Most of these regions are transposon-rich, poorly transcribed, and lack the euchromatin mark H3K4me2 but are embedded within regions with the heterochromatin marks H3K9me3 and H3K27me3.
2020-01-07 | GSE143137 | GEO
Project description:Specification and propagation of the centromeres of eukaryotic chromosomes is determined by epigenetic mechanisms. Unfortunately, the epigenetic characteristics of centromeric DNA and chromatin are difficult to define because the centromeres are composed of highly repetitive DNA sequences in most eukaryotic species. Several rice centromeres have been fully sequenced, making rice an excellent model for centromere research. We conducted genome-wide mapping of cytosine methylation using methylcytosine immunoprecipitation combined with Illumina sequencing. The DNA sequences in the core domains of rice Cen4, Cen5, and Cen8 showed elevated methylation levels compared to the sequences in the pericentromeric regions. In addition, elevated methylation levels were associated with the DNA sequences in the CENH3-binding subdomains compared to the sequences in the flanking H3 subdomains. In contrast, the centromeric domain of Cen11, which is composed exclusively of centromeric satellite DNA, is hypomethylated compared to the pericentromeric domains. Thus, the DNA sequences associated with functional centromeres can be either hypomethylated or hypermethylated. The methylation patterns of centromeric DNA appear to be correlated with the composition of the associated DNA sequences. We propose that both hypomethylation and hypermethylation of CENH3-associated DNA sequences can serve as epigenetic marks to distinguish where CENH3 deposition will occur within the surrounding H3 chromatin. mCIP-seq of one sample of rice seedling
2010-04-22 | E-GEOD-21414 | biostudies-arrayexpress
Project description:Accurate chromosome segregation requires centromeres (CENs), the chromosomal sites where kinetochores form, to bridge DNA and attach to microtubules. In contrast to most eukaryotes, Saccharomyces cerevisiae possesses sequence-defined point centromeres. Chromatin immunoprecipitation followed by sequencing (ChIP-Seq) of four kinetochore components reveals regions of overlapping, extra-centromeric protein localization upon overproduction of the centromeric histone, Cse4 (CENP-A or CenH3). These identified sequences enhance proper plasmid and chromosome segregation, and are termed Centromere-like Regions (CLRs). CLRs form in close proximity to S. cerevisiae CENs and share characteristics typical of point and regional centromeres. CLR sequences are conserved among related budding yeasts, suggesting a role in vivo. These studies provide new insights into the origin and evolution of centromeres.
2013-01-18 | GSE31466 | GEO
Project description:CENP-A is a centromere-specific histone 3 variant essential for centromere specification. CENP-A partially replaces canonical histone H3 at the centromeres. How the particular CENP-A/H3 ratio at centromeres is precisely maintained is unknown. It also remains unclear how CENP-A is excluded from non-centromeric chromatin. Here we identify Ccp1, an uncharacterized NAP family protein in fission yeast that antagonizes CENP-A loading at both centromeric and non-centromeric regions. Like the CENP-A loading factor HJURP, Ccp1 interacts with CENP-A, and is recruited to centromeres at the end of mitosis in a Mis16-dependent manner. These data indicate that factors with opposing CENP-A loading activities are recruited to centromeres. Furthermore, Ccp1 also cooperates with H2A.Z to evict CENP-A assembled in euchromatin. Structural analyses indicate that Ccp1 forms a homodimer that is required for its anti-CENP-A loading activity. Our study establishes mechanisms for maintenance of CENP-A homeostasis at centromeres and the prevention of ectopic assembly of centromeres. Examination of cnp1 distribution in one wild type (wt) and two ccp1 mutants.
2016-08-04 | E-GEOD-85166 | biostudies-arrayexpress
Project description:The signal for maternal recognition of pregnancy (MRP) has still not been identified in the horse. Endometrial biopsies, uterine fluid, embryonic tissues and yolk sac fluid were collected 13 days after ovulation during pregnant and control cycles from the same mares. Micro-RNA-Sequencing was performed on all collected samples and mRNA-Sequencing was conducted on the same endometrial and embryonic tissue samples
2020-02-24 | GSE141443 | GEO
Project description:The centromere is a defining feature of eukaryotic chromosomes and is essential for the segregation of chromosomes during cell division. Centromeres are universally marked by the histone variant cenH3 and are restricted to specialized chromatin that most commonly localized to a single position along the chromosome. However, the DNA on which centromeric nucleosomes assemble is not conserved and varies greatly in size and composition. It ranges from genetically defined point centromeres that assemble a single cenH3-containing nucleosome to epigenetically defined regional centromeres embedded in megabases of tandemly repeated DNA to holocentromeres that extend along the length of the entire chromosomes. The organization of regional and holocentric centromeres has so far been elusive, as the precise locations of cenH3-containing sequences could not be determined. Our results show that the point centromere is the basic unit of holocentromeres and provide a basis for understanding how centromeric chromatin is maintained. We use high-resolution mapping of cenH3-associated DNA to show that Caenorhabditids elegans holocentromeres are organized as dispersed but discretely localized point centromeres.
2014-04-08 | E-GEOD-44412 | biostudies-arrayexpress