Removing the constraining requirements at gene editing site
Many basic and clinical researchers are testing the potential of a simple and efficient gene editing approach to study and correct disease-causing mutations for conditions ranging from blindness to cancer, but the technology is constrained by a requirement that a certain short DNA sequence be present at the gene editing site. Now investigators at Massachusetts General Hospital (MGH) have modified the system to be nearly free of this requirement, making it possible to potentially target any location across the entire human genome. Their advance is described in Science. The clustered regularly interspaced short palindromic repeat (CRISPR) — associated protein 9 (Cas9) genome editing technology is a defense strategy used by bacteria to make cuts to the DNA of invading viruses. For the CRISPR-Cas9 system to work, a bacterial defense protein called Cas9 seeks out a short region — called a protospacer adjacent motif (or PAM) — that is present in the viral DNA but...