Related Experiment Video
Updated: May 15, 2026
11:06
Method for the Isolation of Francisella tularensis Outer Membranes
Published on: June 29, 2010
First indication for a functional CRISPR/Cas system in Francisella tularensis
Eva Schunder1, Kerstin Rydzewski, Roland Grunow
1Cellular Interactions of Bacterial Pathogens, Centre for Biological Security, Division 2 (ZBS2), Robert Koch-Institute, Berlin, Germany.
International Journal of Medical Microbiology : IJMM
|January 22, 2013
Summary
Francisella tularensis subsp. novicida U112 possesses a functional CRISPR/Cas system, a bacterial defense mechanism. This finding suggests a novel aspect of this zoonotic pathogen
Area of Science:
- Microbiology
- Bacterial Genetics
- Immunology
Background:
- Francisella tularensis is a zoonotic bacterium causing tularemia and a potential biothreat agent.
- F. tularensis subsp. novicida is associated with aquatic environments.
- CRISPR/Cas systems provide adaptive immunity against foreign genetic elements in bacteria.
Purpose of the Study:
- To investigate the presence and functionality of a CRISPR/Cas system in Francisella tularensis subsp. novicida.
- To analyze the genomic data for evidence of CRISPR/Cas components and associated spacers.
Main Methods:
- In silico analysis of the F. tularensis subsp. novicida U112 genome.
- Identification of CRISPR/Cas system components.
- Homology search for spacer sequences against known genetic elements.
Main Results:
- A putative functional CRISPR/Cas system was identified in F. tularensis subsp. novicida U112.
- Spacer DNAs homologous to a putative phage were found in F. tularensis subsp. novicida-like strain 3523.
- CRISPR/Cas systems in other F. tularensis subspecies (tularensis, holarctica, mediasiatica) appear non-functional.
Conclusions:
- This study provides the first evidence for a functional CRISPR/Cas defense system in F. tularensis subsp. novicida.
- The identified system may play a role in the bacterium's interaction with mobile genetic elements like phages.
- The differential functionality of CRISPR/Cas systems across F. tularensis subspecies warrants further investigation.
Related Concept Videos
02:53CRISPR and crRNAs
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...
01:23The Antiviral System of Bacteria and Archaea: CRISPR
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 defense.
01:59CRISPR
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 Short...