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
Adaptive antiviral defense mechanisms, in archaea and bacteria, based on DNA repeat arrays called clustered regularly interspaced short palindromic repeats (crispr elements) that function in conjunction with crispr-associated proteins (Cas proteins). Several types have been distinguished, including Type I, Type II, and Type III, based on signature motifs of crispr-associated proteins.
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: CRISPR-Cas System; CRISPR Cas Systems; System, CRISPR-Cas; Systems, CRISPR-Cas.
Where it fits in the MeSH classification
- Broader topics
- Gene Silencing
- See also
- Gene Editing; CRISPR-Associated Protein 9
Related concepts
Research landscape
PubMed indexes 27,687 records tagged with the MeSH heading “CRISPR-Cas Systems” (counts retrieved 2026-10-29). 19,434 of them (70.2%) were published from 2020 onward, and the busiest period so far is 2020 onward with 19,434 records.
Reviews account for 4,466 records (16.1%) and meta-analyses for 25. Randomized controlled trials number 2 (0.0%) 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 | 0 |
| 2000-2009 | 0 |
| 2010-2019 | 8,501 |
| 2020 onward | 19,434 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 4,466 | 16.1% |
| Meta-analyses | 25 | 0.1% |
| Randomized controlled trials | 2 | 0.0% |
Method: PubMed query "CRISPR-Cas Systems"[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 |
|---|---|---|---|---|
| Structural basis of supercoiling-induced CRISPR-Cas9 off-target activity | 2026 | Research article Design not recorded in structured metadata | 7 | cc by PMID 41882360 · DOI · PMC13171457 |
| A massively parallel CRISPR-based screening platform for modifiers of neuronal depolarization | 2026 | Research article Design not recorded in structured metadata | 4 | cc by PMID 42669708 · DOI · PMC13526836 |
| Optimised genome editing for precise DNA insertion and substitution using prime editors in zebrafish | 2026 | Research article Design not recorded in structured metadata | 4 | cc by PMID 42411453 · DOI · PMC13341114 |
Structural basis of supercoiling-induced CRISPR-Cas9 off-target activity [1]
Abstract reading summary — source excerpts
- Opening excerpt
- CRISPR-Cas9 is a powerful genome-editing tool1, but genome-wide off-target activity can hinder therapeutic applications.
- Closing excerpt
- Together, our study reveals the molecular basis for (-)SC-induced Cas9 targeting and provides a framework for the design of next-generation high-fidelity CRISPR effectors with topological context.
- 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 (126 words)
CRISPR-Cas9 is a powerful genome-editing tool1, but genome-wide off-target activity can hinder therapeutic applications. Negative supercoiling ((-)SC) has been implicated in off-target activity, but a molecular-level understanding is lacking. Here, using (-)SC DNA minicircles, we observe supercoiling-driven structural defects in the DNA that are resolved by Cas9 binding. Cryo-electron microscopy structures of Cas9 bound in both the on-target and off-target configurations highlight that the Cas9 HNH domain is poised in a more catalytically competent conformation. New DNA-RNA mismatch geometries are accommodated across the protospacer and structural plasticity in the protospacer adjacent motif distal region of the protospacer is topology dependent. Together, our study reveals the molecular basis for (-)SC-induced Cas9 targeting and provides a framework for the design of next-generation high-fidelity CRISPR effectors with topological context.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41882360 · DOI · PMC13171457
A massively parallel CRISPR-based screening platform for modifiers of neuronal depolarization [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Understanding the complex interplay between gene expression and neuronal activity is crucial for unraveling the molecular mechanisms underlying cognitive function and neurological disorders.
- Closing excerpt
- This CRISPRi-based screening platform offers a versatile tool to uncover molecular mechanisms controlling neuronal function in health and disease.
- 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 (124 words)
Understanding the complex interplay between gene expression and neuronal activity is crucial for unraveling the molecular mechanisms underlying cognitive function and neurological disorders. Here, we developed pooled screens using CRISPR interference (CRISPRi) and the fluorescent calcium integrator CaMPARI2 to evaluate genetic modifiers of neuronal depolarization. Using this screening method, we evaluated 1343 genes for their effect on depolarization in a human iPSC-derived neuron model, revealing potential links to neurodegenerative and neurodevelopmental disorders. These genes include known regulators of neuronal excitability, such as TARPs and ion channels, as well as genes associated with autism spectrum disorder and Alzheimer's disease not previously described to affect neuronal depolarization. This CRISPRi-based screening platform offers a versatile tool to uncover molecular mechanisms controlling neuronal function in health and disease.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42669708 · DOI · PMC13526836
Optimised genome editing for precise DNA insertion and substitution using prime editors in zebrafish [3]
Abstract reading summary — source excerpts
- Opening excerpt
- CRISPR/Cas9-mediated genome editing has rapidly become a popular tool for studying gene functions and generating genetically modified organisms.
- Closing excerpt
- We show that PE-mediated prime editing can efficiently manipulate genome information in zebrafish without using exogenous donor DNA.
- 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 (171 words)
CRISPR/Cas9-mediated genome editing has rapidly become a popular tool for studying gene functions and generating genetically modified organisms. However, using this system, stochastic integration of random insertions and deletions restricts precise genome manipulation. Advanced CRISPR/Cas9 technologies using Prime Editors (PEs), Cas9 proteins fused with reverse transcriptase, enable programmed integration of short DNA modifications into the genome. However, its application in precise genome editing in animal models is challenging. Here, we utilise a nickase- and a nuclease-based PE to perform programmed short DNA substitutions and insertions at various loci in the zebrafish genome. Whereas nickase-based PE2 mediated a higher ratio of precise prime edits to the total edits, nuclease-based PEn was more efficient for short DNA modifications, achieving up to 27.3% precise insertion. To further evaluate our approach, we inserted a nuclear localisation signal into a reporter transgene to incorporate longer fragments by prime editing. These gene modifications were transmitted to the next generation. We show that PE-mediated prime editing can efficiently manipulate genome information in zebrafish without using exogenous donor DNA.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42411453 · DOI · PMC13341114
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 Inhibition of long non-coding RNA UCA1 by CRISPR/Cas9 attenuated malignant phenotypes of bladder cancer [4]
- Research article An overview and metanalysis of machine and deep learning-based CRISPR gRNA design tools [5]
- Research article The hidden risks of CRISPR/Cas: structural variations and genome integrity [6]
- Research article Revolutionizing CRISPR technology with artificial intelligence [7]
- Research article CRISPR-driven diagnostics: Molecular mechanisms, clinical efficacy and translational challenges [8]
- Research article One-Pot Isothermal Nucleic Acid Amplification Assisted CRISPR/Cas Detection Technology: Challenges, Strategies, and Perspectives [9]
References
- Smith QM, Whittle S, Aramayo RJ, Rollins DE, Jalal ASB, Egharevba DI, et al.. Structural basis of supercoiling-induced CRISPR-Cas9 off-target activity. . 2026. PMID 41882360 · DOI · PMC13171457
- Boggess SC, Gandhi V, Tsai MC, Marzette E, Teyssier N, Chou JY, et al.. A massively parallel CRISPR-based screening platform for modifiers of neuronal depolarization. . 2026. PMID 42669708 · DOI · PMC13526836
- Ono Y, Peterka M, Love M, Khan A, Bowers F, Bhandari A, et al.. Optimised genome editing for precise DNA insertion and substitution using prime editors in zebrafish. . 2026. PMID 42411453 · DOI · PMC13341114
- Zhen S, Hua L, Liu YH, Sun XM, Jiang MM, Chen W, et al.. Inhibition of long non-coding RNA UCA1 by CRISPR/Cas9 attenuated malignant phenotypes of bladder cancer. Oncotarget. 2017. PMID 28038452 · DOI · PMC5354759
- Wang J, Zhang X, Cheng L, Luo Y. An overview and metanalysis of machine and deep learning-based CRISPR gRNA design tools. RNA Biol. 2020. PMID 31533522 · DOI · PMC6948960
- Aussel C, Cathomen T, Fuster-García C. The hidden risks of CRISPR/Cas: structural variations and genome integrity. Nat Commun. 2025. PMID 40764301 · DOI · PMC12325979
- Kim MG, Go MJ, Kang SH, Jeong SH, Lim K. Revolutionizing CRISPR technology with artificial intelligence. Exp Mol Med. 2025. PMID 40745000 · DOI · PMC12322281
- Wang Z, Wang Q, Zhang J, Li B, Li Y, Chen Z, et al.. CRISPR-driven diagnostics: Molecular mechanisms, clinical efficacy and translational challenges. Clin Transl Med. 2025. PMID 41000010 · DOI · PMC12464570
- Liu H, Yin H, Xiu L, Wu W, Hu Q, Xia Y, et al.. One-Pot Isothermal Nucleic Acid Amplification Assisted CRISPR/Cas Detection Technology: Challenges, Strategies, and Perspectives. Adv Sci (Weinh). 2025. PMID 40884263 · DOI · PMC12499467
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.