Photo shoot for CRISPR

Before CRISPR-based gene editing can be safely used in humans, major questions need to be answered about how to direct the activity only to target tissues, and how to turn the activity on and off on demand. Scientists at the University of Tokyo have found that photoactivation of the key CRISPR-associated protein 9 (Cas9) enzyme could allow both spatial and temporal control of the technology, and think it could be a first step to producing a safe version.

"This is the first tool that allows on/off-switching of genome-editing capabilities," said Moritoshi Sato, an associate professor at the university and principal investigator on the study. "Cas9 often suffers from off-target effects due to its uncontrollable nuclease activity," and doesn't reach several tissues, such as the brain...