Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

CRISPR/Cas9 Genome Editing01:28

CRISPR/Cas9 Genome Editing

2.4K
The CRISPR-Cas system serves as a bacterial defense mechanism against invading genetic elements such as viruses and plasmids, forming the foundation for its adaptation as a powerful genome-editing tool. Originally discovered in prokaryotes, this system has been repurposed to revolutionize genetic engineering across a wide range of organisms, including plants, animals, and humans. The core component, Cas9, is an endonuclease derived from Streptococcus pyogenes, capable of introducing...
2.4K
The Antiviral System of Bacteria and Archaea: CRISPR01:23

The Antiviral System of Bacteria and Archaea: CRISPR

899
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats is a adaptive immune system found in bacteria and archaea that protects against viral infections. This system enables prokaryotic cells to identify, remember, and neutralize foreign genetic elements, primarily bacteriophages, by storing fragments of the invader’s DNA as a genetic memory.The CRISPR immune response begins during an initial infection. Cas (CRISPR-associated) proteins play a central role in this...
899
CRISPR and crRNAs02:53

CRISPR and crRNAs

19.5K
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
19.5K
CRISPR01:59

CRISPR

58.7K
Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced...
58.7K
CRISPR01:59

CRISPR

18.8K
18.8K
Homologous Recombination02:31

Homologous Recombination

65.0K
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
65.0K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Programming T cells for intercellular genome editing.

bioRxiv : the preprint server for biology·2026
Same author

Harmonizing standards and resources for the medical genome.

Nature·2026
Same author

Publisher Correction: Lung and liver editing by lipid nanoparticle delivery of a stable CRISPR-Cas9 ribonucleoprotein.

Nature biotechnology·2026
Same author

Targeting cancer-specific mutations with RNA-triggered chromatin shredding.

Nature·2026
Same author

Selective Elimination of TP53 Mutant Cells by Transcript-Activated Chromatin Shredding.

bioRxiv : the preprint server for biology·2026
Same author

A Noncontiguous Code for RNA-Guided DNA Recognition Preceded CRISPR.

bioRxiv : the preprint server for biology·2026

Related Experiment Video

Updated: Mar 15, 2026

Genome-Wide CRISPR Screen for Unveiling Radiosensitive and Radioresistant Genes
08:32

Genome-Wide CRISPR Screen for Unveiling Radiosensitive and Radioresistant Genes

Published on: May 23, 2025

1.4K

Protecting genome integrity during CRISPR immune adaptation.

Addison V Wright1, Jennifer A Doudna1,2,3,4,5,6

  • 1Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.

Nature Structural & Molecular Biology
|September 6, 2016
PubMed
Summary

Bacterial CRISPR-Cas systems use DNA integration for viral defense. Researchers found that Streptococcus pyogenes Cas1-Cas2 integrase limits integration at incorrect sites, preventing genome damage and ensuring host integrity.

More Related Videos

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms
09:51

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms

Published on: May 25, 2018

36.2K
Selection-dependent and Independent Generation of CRISPR/Cas9-mediated Gene Knockouts in Mammalian Cells
11:35

Selection-dependent and Independent Generation of CRISPR/Cas9-mediated Gene Knockouts in Mammalian Cells

Published on: June 16, 2017

13.4K

Related Experiment Videos

Last Updated: Mar 15, 2026

Genome-Wide CRISPR Screen for Unveiling Radiosensitive and Radioresistant Genes
08:32

Genome-Wide CRISPR Screen for Unveiling Radiosensitive and Radioresistant Genes

Published on: May 23, 2025

1.4K
Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms
09:51

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms

Published on: May 25, 2018

36.2K
Selection-dependent and Independent Generation of CRISPR/Cas9-mediated Gene Knockouts in Mammalian Cells
11:35

Selection-dependent and Independent Generation of CRISPR/Cas9-mediated Gene Knockouts in Mammalian Cells

Published on: June 16, 2017

13.4K

Area of Science:

  • Molecular Biology
  • Genetics
  • Microbiology

Background:

  • Bacterial CRISPR-Cas systems provide adaptive immunity against viruses through foreign DNA integration.
  • Specific DNA integration is crucial to prevent genome damage, yet in vitro studies show promiscuous activity.
  • The Streptococcus pyogenes type II-A Cas1-Cas2 integrase is key to this process.

Purpose of the Study:

  • To reconstitute and analyze the full-site DNA integration mechanism of the S. pyogenes Cas1-Cas2 integrase.
  • To understand how specificity is maintained during CRISPR immune adaptation.
  • To investigate the factors limiting promiscuous DNA integration at non-target sites.

Main Methods:

  • Reconstitution of full-site DNA integration assays.
  • In vitro characterization of Streptococcus pyogenes type II-A Cas1-Cas2 integrase activity.
  • Analysis of DNA integration intermediates and reaction kinetics.

Main Results:

  • The S. pyogenes Cas1-Cas2 integrase exhibits specificity by stalling integration at non-CRISPR sites, allowing reaction reversal.
  • Integration is limited at the second step, preventing aberrant insertions.
  • The integrase specifically recognizes the leader-proximal repeat, particularly its palindromic ends.

Conclusions:

  • Cas1-Cas2 integrase employs specific mechanisms to prevent DNA insertion at incorrect genomic locations.
  • The frequency of off-target DNA insertion sites is lower than previously assumed.
  • These specificity mechanisms are vital for preventing host toxicity and maintaining genome integrity during CRISPR adaptation.