Gene Editing
Why is it in news?
- Recently scientists said that they had succeeded for the first time in wiping out an entire population of malaria-carrying mosquitoes in the lab using a gene editing tool to programme their extinction.
- In experiments with the species Anopheles gambiae , scientists at Imperial College London tweaked a gene known as doublesex so that more females in each generation could no longer bite or reproduce.
More in news
- After only eight generations, there were no females left and the population collapsed due to lack of offspring.
- This breakthrough shows that gene drive can work, providing hopes in the fight against a disease that has plagued mankind for centuries.
- Malaria affected more than 200 million people worldwide in 2016 and killed nearly 4,50,000.
- It remains one of the most deadly of infectious diseases.
Gene Editing
What is Genome Editing?
- It is a type of genetic engineering in which DNA is inserted, deleted or replaced in the genome of an organism using engineered nucleases, or “molecular scissors”.
- These nucleases or enzymes create site-specific double-strand breaks (DSBs) at desired locations.
- The induced double-strand breaks are repaired through end joining or recombination, resulting in targeted mutation.
- Currently, there are four families of engineered nucleases which are being used-1) Meganucleases,2) Zinc finger nucleases (ZFNs),3) Transcription activator-like effector-based nucleases (TALEN),4) Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system.
What is CRISPR-Cas9?
- CRISPR is a dynamic, versatile tool that allows us to target nearly any genomic location and potentially repair broken genes.
- It can remove, add or alter specific DNA sequences in the genome of higher organisms.
- CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) are sections of DNA and are sections of genetic code containing short repetitions of base sequences followed by spacer DNA segments.
- CAS-9 (CRISPR-associated protein 9) is an enzyme.
- It uses a synthetic guide RNA to introduce a double strand break at a specific location within a strand of DNA.
- It is a system used by bacterial cells to recognize and destroy viral DNA as a form of adaptive immunity.
Source
The Hindu