Genetics · 6 min read
CRISPR: How Bacteria Taught Us to Edit Genes
A microbial immune system became the most precise gene-editing tool ever built.
Long before scientists edited genes, bacteria were cutting viral DNA to defend themselves. Repeating DNA sequences called CRISPR store snippets of past invaders, acting like a molecular memory.
In 2012, Jennifer Doudna and Emmanuelle Charpentier showed that the Cas9 protein, guided by a short RNA, could be programmed to cut any DNA sequence chosen by a researcher. That insight earned the 2020 Nobel Prize in Chemistry.
Today CRISPR is used in labs worldwide, and in 2023 the first CRISPR-based therapy, Casgevy, was approved to treat sickle cell disease—a milestone for medicine.