Rice University CRISPR-2

CRISPR-Cas9 gene editing relies on a targeting sequence of RNA and the cutting endonuclease Cas9. In the targeting sequence of the original CRISPR molecule taken from Streptococcus pyogenes, the RNA guides which make up “protospacer-adjacent motifs” are only three to five bases long. Were these bases longer, the targeting sequence would have greater specificity, instead of the “off-target” hits now limiting this means of gene editing. Recently, researchers at Rice University reported longer RNA sequences—eight bps—they discovered in two other bacteria, Neisseria meningitides, and Streptococcus thermophiles. These “Nme” and “Sth” sequences, along with the Cas9 nuclease are small enough to fit within an adeno-associated virus delivery system. MORE

Image Credit: Bao Lab Rice University