CRISPR
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a natural bacterial adaptive immune system that has been adapted into the most precise and widely used gene-editing tool in biology. CRISPR-Cas9 edits DNA with single-nucleotide precision at any sequence in a genome.
How It Works
CRISPR-Cas9 consists of two components: a guide RNA (gRNA) that specifies the target sequence and the Cas9 nuclease that cuts DNA. The ~20-nucleotide guide sequence base-pairs with the target DNA, Cas9 binds the complex, and both strands are cut. The cell's own repair machinery then determines the editing outcome.
NHEJ (non-homologous end joining) is error-prone and usually introduces small insertions or deletions that disrupt the gene. HDR (homology-directed repair) uses a template to install a precise sequence change — but requires delivering the template alongside the CRISPR components.
Applications in Food
CRISPR has been used to remove allergens in soybeans, eliminate acrylamide precursors in potatoes, increase yield in wheat, and engineer disease resistance in bananas. In flavor engineering, it enables targeted manipulation of biosynthesis pathway genes — turning specific steps up, down, or off with precision not achievable by conventional breeding.