Gene editing involves the insertion, removal or replacement of DNA within the genome of a living organism
- The most precise, efficient and flexible method of gene editing currently available involves the CRISPR editing system
CRISPR is a short sequence of DNA which functions as a target for CRISPR-associated nucleases (Cas nuclease)
- CRISPR stands for ‘clustered regularly interspaced short palindromic repeats’
- CRISPR provides bacterial immunity to viruses by flanking viral DNA sequences that have been integrated into the genome
- The viral DNA is transcribed into an RNA sequence that – via CRISPR – associates with a Cas nuclease
- The viral RNA and Cas nuclease drift throughout the cell until the viral RNA identifies and binds to complementary viral DNA
- This enables the Cas nuclease to target and destroy the viral DNA sequence, preventing infection
The CRISPR / Cas system has been modified to selectively remove any targeted sequence, allowing for precise gene editing
- The Cas protein is complexed with a synthetically derived guide RNA molecule that is complementary to a target sequence
- The guide RNA will bind to the target sequence, prompting its excision by the Cas nuclease
- Following the removal of the target sequence, another sequence of DNA can be integrated in its place (gene editing)
Gene Editing via the CRISPR / Cas System
