Related Experiment Video
Updated: Feb 14, 2026
10:52
Precise Phage Mutagenesis with NgTET-Assisted CRISPR-Cas Systems
Published on: October 14, 2025
694
The double-edged sword of CRISPR-Cas systems
Manuela Villion1, Sylvain Moineau
1Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Groupe de Recherche en Écologie Buccale, Faculté de Médecine Dentaire, Félix d'Hérelle Reference Center for Bacterial Viruses, Université Laval, Québec City, Quebec G1V 0A6, Canada.
Cell Research
|September 5, 2012
Summary
Specific small RNAs can program proteins to cut unwanted DNA, offering microbial cells a novel defense mechanism. This discovery enhances our understanding of cellular immunity and gene editing potential.
Area of Science:
- Molecular Biology
- Genetics
- Microbial Immunity
Background:
- Microbial cells possess defense systems against foreign genetic material.
- Small RNAs play crucial roles in gene regulation and cellular processes.
Purpose of the Study:
- To elucidate the mechanism by which small RNAs direct protein-guided DNA cleavage.
- To explore the potential of this system for conferring immunity in microbial cells.
Main Methods:
- Investigated the interaction between specific small RNAs and target DNA sequences.
- Characterized the enzymatic activity of programmed proteins responsible for DNA cleavage.
- Assessed the efficacy of the system in providing resistance against foreign DNA in microbial hosts.
Main Results:
- Demonstrated that small RNAs can precisely program a protein to cleave specific DNA sequences.
- Showcased the successful implementation of this system to grant microbial cells immunity against invading DNA.
- Identified the key components and steps involved in the RNA-programmed DNA targeting process.
Conclusions:
- Small RNA-programmed DNA cleavage represents a novel and potent mechanism for microbial defense.
- This system has significant implications for understanding cellular immunity and developing new biotechnological tools for gene editing.
Related Concept Videos
02:53CRISPR and crRNAs
19.2K
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...
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...
19.2K
01:59CRISPR
58.0K
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...
58.0K
02:04Fixing Double-strand Breaks
15.0K
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
15.0K
01:18Second Order systems II
414
In an underdamped second-order system, where the damping ratio ζ is between 0 and 1, a unit-step input results in a transfer function that, when transformed using the inverse Laplace method, reveals the output response. The output exhibits a damped sinusoidal oscillation, and the difference between the input and output is termed the error signal. This error signal also demonstrates damped oscillatory behavior. Eventually, as the system reaches a steady state, the error diminishes to zero.
414
01:21First Order Systems
435
First-order systems, such as RC circuits, are foundational in understanding dynamic systems due to their straightforward input-output relationship. Analyzing their responses to different input functions under zero initial conditions reveals significant insights into system behavior.
When a first-order system is subjected to a unit-step input, its response is characterized by its transfer function. By applying the Laplace transform of the unit-step input to the transfer function, expanding the...
When a first-order system is subjected to a unit-step input, its response is characterized by its transfer function. By applying the Laplace transform of the unit-step input to the transfer function, expanding the...
435
01:20Second Order systems I
619
A servo system exemplifies a second-order system, featuring a proportional controller and load elements that ensure the output position aligns with the input position. The relationship between these components is described by a second-order differential equation. Applying the Laplace transform under zero initial conditions yields the transfer function, showing how inputs are converted to outputs in the system.
By reinterpreting the system, one can derive the closed-loop transfer function, which...
By reinterpreting the system, one can derive the closed-loop transfer function, which...
619