What is CRISPR, and why is it called 'genetic scissors'?

The answer

CRISPR-Cas9 is a gene-editing tool adapted from a natural defense system bacteria use against viruses. It uses a guide RNA to locate a specific DNA sequence and the Cas9 enzyme to cut the DNA at that exact spot - like molecular scissors. Scientists can then delete, repair, or insert genes at the cut site. Since its 2012 development by Jennifer Doudna and Emmanuelle Charpentier (2020 Nobel Prize), CRISPR has been used to develop disease-resistant crops, eliminate malaria-carrying mosquitoes in trials, and create the first CRISPR-based therapy (Casgevy) approved for sickle cell disease in 2023.