Crispr-Cas9 system works on the concept of bacterial defence mechanism. The idea of which was replicated in eukaryotic cell in in- vitro condition by the researchers.
1. CRISPR-Cas9 technology
NAME : KRANTI BHOSALE
ID : 55543
DEPARTMENT : BIOCHEMISTRY
COURSE : MASTER SEMINAR (BBC-600)
COURSE INSTRUCTOR : DR. ASHUTOSH DUBEY
2. What is CRISPR-Cas9?
• CRISPR (Clustered Regularly Interspaced Short Palindromic
Repeats).
• Genome editing system- Manipulate genes in different organisms.
• Major components- CRISPR (Small segment of RNA structure)
Cas9 (Nuclease Protein)
• The complex cleaves target DNA at specific location.
3. Origin of CRISPR-Cas9 System
• Concept – Bacterial defence against viral attack (acquired immunity)
• The phage genome- CRISPR kind of sequences.
• Bacteriophages attack the bacteria and destroys it during the growth of bacteriophage.
• When viral genome released for next time, the bacteria already has viral genetic
material as a copy or memory.
• Bacterial cell produces RNA copy (crRNA) along with Cas9 protein.
• The CRISPR-Cas9 complex interacts with the viral genome and cleaves the target
DNA.
• Scientists tried to replicate the process in in-vitro studies
4. Figure 1: CRISPR-Cas9: The bacterial defence mechanism. A: Cas9 enzyme
1. Virus invades bacterial cell; 2. Nucleic acid derived from virus is integrated into the bacterial nucleic acid at CRISPR
location; 3. crRNA is formed; 4. crRNA attaches to Cas9 enzyme; 5. crRNA guides the enzyme to the virus. It cuts and
destroys the viral genome.
5. CRISPR-Cas9:
USED IN EUKARYOTIC ORGANISMS
• Technique- manipulated and used in variety of eukaryotic organisms and cell
types.
• Able to make modifications in somatic cells.
components of CRISPR/Cas delivered by several delivery methods
6.
7. Advantage of using CRISPR-Cas9 system:
1. The total DNA content can be changed.
2. The function of the gene can be analyzed.
3. If tagged with fluorescent dye, the CRISPR-Cas9 can mark specific region or specific DNA in the whole
genome of complicated organism. E.g. Humans
Applications:
1. Food industry
Immunization of bacteria used in food production against viruses (cheese/yogurt)
2. Medical Treatment
CRISPR therapy would allow silencing of defective genes (Huntington Disease)
3. Agriculture
Development of disease resistant transgenic plants,
Increased oil production in (Canola crop), etc.
8. Nobel Prize Winners in Chemistry
(2020)
Emmanuelle Charpentier Jennifer A. Doudna
