Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 3 complete abstracts (421 words), 9 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton and Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Chromosome.
Where it fits in the MeSH classification
- Broader topics
- Cellular Structures; Intranuclear Space; Genetic Structures
- Narrower topics
- Chromosomes, Archaeal; Chromosomes, Artificial; Chromosomes, Bacterial; Chromosomes, Fungal; Chromosomes, Insect; Chromosomes, Mammalian; Chromosomes, Plant; Isochromosomes; Ring Chromosomes; Sex Chromosomes; Chromosome Structures; Polytene Chromosomes; Karyotype
- See also
- Karyotyping
Research landscape
PubMed indexes 308,970 records tagged with the MeSH heading “Chromosomes” (counts retrieved 2026-10-29). 37,866 of them (12.3%) were published from 2020 onward, and the busiest period so far is through 1999 with 123,755 records.
Reviews account for 32,394 records (10.5%) and meta-analyses for 797. Randomized controlled trials number 400 (0.1%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 123,755 |
| 2000-2009 | 76,280 |
| 2010-2019 | 71,069 |
| 2020 onward | 37,866 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 32,394 | 10.5% |
| Meta-analyses | 797 | 0.3% |
| Randomized controlled trials | 400 | 0.1% |
Method: PubMed query "Chromosomes"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in genetics and genomics
Genetic findings vary widely in strength. A variant linked to a condition in one study may not replicate in other ancestries, and most common variants have small effects that are meaningful only in aggregate. Studies of rare, high-impact variants can support strong causal claims about a gene, while association studies describe statistical links that need functional and independent replication. Check the sample size, the ancestry of participants, whether results were replicated, and whether a laboratory or clinical outcome was actually measured.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Molecular architecture of heterochromatin at the nuclear periphery of primary human cells | 2026 | Research article Design not recorded in structured metadata | 11 | cc by PMID 42399220 · DOI · PMC13332202 |
| Single-cell chromatin state transitions during epigenetic memory formation | 2026 | Research article Design not recorded in structured metadata | 9 | cc by PMID 42490451 · DOI · PMC13394403 |
| Cohesin prevents local mixing of condensed euchromatic domains in living human cells | 2026 | Research article Design not recorded in structured metadata | 6 | cc by PMID 42711428 · DOI · PMC13553310 |
Molecular architecture of heterochromatin at the nuclear periphery of primary human cells [1]
Abstract reading summary — source excerpts
- Opening excerpt
- In eukaryotes, meters of DNA are packaged into micrometer scale nuclei.
- Closing excerpt
- In situ structural biology thus reveals the molecular chromatin organization inside cells and sets the stage for 3D genomics.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (121 words)
In eukaryotes, meters of DNA are packaged into micrometer scale nuclei. Nucleosomes, as the major organizational unit, have been extensively studied in vitro, yet the elaborate 3D structure of chromatin inside cells and its distinct oligo-nucleosome arrangements remain poorly resolved. Here, we combine cryo-electron tomography with template matching, subtomogram averaging and molecular simulations to visualize nucleosomes and chromatin structure inside human cells. We confidently assign individual nucleosomes and report their in-situ structure at secondary structure resolution. By predicting the paths of linker DNA, we identify oligo-nucleosome arrangements and uncover higher-order chromatin structures in situ, including a 37-nm wide, elongated but non-fibrous arrangement. In situ structural biology thus reveals the molecular chromatin organization inside cells and sets the stage for 3D genomics.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42399220 · DOI · PMC13332202
Single-cell chromatin state transitions during epigenetic memory formation [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Repressive chromatin modifications compact chromatin and mediate heritable gene silencing, but how structural changes quantitatively relate to epigenetic memory remains unclear.
- Closing excerpt
- Similar compaction is observed at endogenous loci during differentiation and fate commitment, suggesting that spatial organization may be predictive of epigenetic memory in other systems.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (150 words)
Repressive chromatin modifications compact chromatin and mediate heritable gene silencing, but how structural changes quantitatively relate to epigenetic memory remains unclear. Using targeted recruitment of the KRAB repressor to induce H3K9me3 at a reporter gene, combined with single-molecule 3D chromatin imaging, we show that irreversible silencing is associated with large-scale chromatin compaction across tens of kilobases. In contrast, histone deacetylation produces reversible silencing without such compaction. Despite substantial single-cell heterogeneity, average compaction at the end of silencing quantitatively predicts epigenetic memory weeks after KRAB removal. Here, memory arises not through stable H3K9me3 domains but rather through a dynamic handoff in which H3K9me3 is gradually lost and replaced by DNA methylation. Stochastic simulations recapitulating these dynamics suggest that compaction enhances read-write feedback to promote this transition. Similar compaction is observed at endogenous loci during differentiation and fate commitment, suggesting that spatial organization may be predictive of epigenetic memory in other systems.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42490451 · DOI · PMC13394403
Cohesin prevents local mixing of condensed euchromatic domains in living human cells [3]
Abstract reading summary — source excerpts
- Opening excerpt
- The human genome is folded into chromatin loops by the cohesin complex, forming functional chromatin domains that underlie transcription and DNA replication/repair.
- Closing excerpt
- These findings suggest a physical role of cohesin in maintaining the integrity of condensed euchromatic domains and ensuring proper higher-order regulation of gene expression.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (150 words)
The human genome is folded into chromatin loops by the cohesin complex, forming functional chromatin domains that underlie transcription and DNA replication/repair. However, how cohesin organizes these domains in living cells, especially in active euchromatin, remains elusive. Here, to address this question, we combined single-nucleosome imaging/tracking and super-resolution three-dimensional structured illumination microscopy with euchromatin-specific labeling of histone variant H3.3. Using this nanoscopic approach, we revealed that euchromatin forms condensed domains that are constrained by cohesin-mediated loops. This organization refines the classical view of euchromatin as largely open, in line with emerging evidence. Transcription machinery appears to be located near the condensed domain surfaces/borders. Cohesin loss increased nucleosome-level fluidity within these domains without altering their overall compaction, leading to local mixing of domains and compromising transcriptional insulation. These findings suggest a physical role of cohesin in maintaining the integrity of condensed euchromatic domains and ensuring proper higher-order regulation of gene expression.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42711428 · DOI · PMC13553310
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Molecular subgroups of medulloblastoma: an international meta-analysis of transcriptome, genetic aberrations, and clinical data of WNT, SHH, Group 3, and Group 4 medulloblastomas [4]
- Research article Meta-analysis and imputation refines the association of 15q25 with smoking quantity [5]
- Research article A breakpoint map of recurrent chromosomal rearrangements in human neoplasia [6]
- Research article Common 5p15.33 and 6p21.33 variants influence lung cancer risk [7]
- Research article Gender and telomere length: systematic review and meta-analysis [8]
- Research article Fusion gene-negative alveolar rhabdomyosarcoma is clinically and molecularly indistinguishable from embryonal rhabdomyosarcoma [9]
References
- Kreysing JP, Cruz-León S, Betz J, Penzo C, Majtner T, Schreiber M, et al.. Molecular architecture of heterochromatin at the nuclear periphery of primary human cells. . 2026. PMID 42399220 · DOI · PMC13332202
- Fujimori T, Thurm AR, Gaudin S, Rios-Martinez C, Doughty BR, Hinks MM, et al.. Single-cell chromatin state transitions during epigenetic memory formation. . 2026. PMID 42490451 · DOI · PMC13394403
- Shimazoe MA, Iida S, Minami K, Higashi K, Tamura S, Kobayashi Y, et al.. Cohesin prevents local mixing of condensed euchromatic domains in living human cells. . 2026. PMID 42711428 · DOI · PMC13553310
- Kool M, Korshunov A, Remke M, Jones DT, Schlanstein M, Northcott PA, et al.. Molecular subgroups of medulloblastoma: an international meta-analysis of transcriptome, genetic aberrations, and clinical data of WNT, SHH, Group 3, and Group 4 medulloblastomas. Acta Neuropathol. 2012. PMID 22358457 · DOI · PMC3306778
- Liu JZ, Tozzi F, Waterworth DM, Pillai SG, Muglia P, Middleton L, et al.. Meta-analysis and imputation refines the association of 15q25 with smoking quantity. Nat Genet. 2010. PMID 20418889 · DOI · PMC3612983
- Mitelman F, Mertens F, Johansson B. A breakpoint map of recurrent chromosomal rearrangements in human neoplasia. Nat Genet. 1997. PMID 9140409 · DOI
- Wang Y, Broderick P, Webb E, Wu X, Vijayakrishnan J, Matakidou A, et al.. Common 5p15.33 and 6p21.33 variants influence lung cancer risk. Nat Genet. 2008. PMID 18978787 · DOI · PMC2695928
- Gardner M, Bann D, Wiley L, Cooper R, Hardy R, Nitsch D, et al.. Gender and telomere length: systematic review and meta-analysis. Exp Gerontol. 2014. PMID 24365661 · DOI · PMC4523138
- Williamson D, Missiaglia E, de Reyniès A, Pierron G, Thuille B, Palenzuela G, et al.. Fusion gene-negative alveolar rhabdomyosarcoma is clinically and molecularly indistinguishable from embryonal rhabdomyosarcoma. J Clin Oncol. 2010. PMID 20351326 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.