CRISPR-like tools that finally can edit mitochondria DNA could be revolutionary

Summary

CRISPR gene editing has made its way into every corner of modern biology, but not into every corner of the cell. Although researchers have used these systems to develop treatments for sickle-cell anaemia and blood cancers, to unlock the secrets of multicellularity and to discover the role of thousands of overlooked proteins, there’s one place CRISPR can’t easily reach: mitochondria.Cancer cells get power boost by stealing mitochondria from nervesThe rings of DNA inside mitochondria are inaccessible to these techniques, which means that precise edits to mitochondrial DNA (mtDNA) remain frustratingly out of reach. “Mitochondria missed the CRISPR–Cas9 revolution that exploded 12 years ago,” says Michal Minczuk, a geneticist at the University of Cambridge, UK.But researchers are eager to access this DNA, says Minczuk. Mitochondria are bean-shaped organelles that power cells and have myriad other cellular tasks. Exploring their DNA is essential for understanding the energy production and exchange that underlies metabolic health. And more than 300 mutations in this DNA cause mitochondrial diseases — incurable genetic disorders with a wide range of symptoms that can rob people of their sight and hearing, trigger muscle problems and spark seizures1. These disorders affect roughly 1 in 5,000 people.Because CRISPR can’t help with these problems, researchers have been looking for other ways to precisely edit the mitochrondrial genome. And the past few years have brought some success: the tools are already proving to be a boon for creating accurate animal models of mitochondrial diseases. “The progress has been remarkable,” says Jin-Soo Kim, a chemical biologist who develops mtDNA editing tools at the Korea Advanced Institute of Science and Technology in Daejeon, South Korea.If researchers can make mtDNA editing safe and accurate enough, it could eventually be used to treat, and even cure, these genetic conditions. “It would be a medical breakthrough,” says Kim.A bacterial orig...