Scientists Make Precise Gene Edits to Mitochondrial DNA for the First Time

 

        When it comes to altering specific segments of the human genome scientists use a process involving CRISPR DNA. This process however could not manage to target or alter the genomes of organelles within a cell like the mitochondria. Scientists have discovered a particular bacterial enzyme that is able to do just that. This enzyme, created by the bacterium Burkholderia cenocepacia, expands the genetic toolbox and allows targeted changes to be made to the mitochondrial genome. These targeted changes may allow researchers to treat diseases caused by mitochondrial genome mutations. Prior to this new technique, scientists lacked the ability to study mitochondrial mutations. The enzyme that is used is called DddA and can directly break double stranded DNA without relying on other enzymes. DddA works by converting cytosine DNA bases into Uracil, because of this it can be very dangerous and must be altered so that it only causes the bases to change when it is orientated in a specific orientation. This enzymes ability to target specific mitochondrial sequences is crucial to its success because in individuals with mitochondrial diseases, a fraction of the mitochondria do not have the diseased gene and it is crucial that the diseased mitochondria is the only one that is altered.

        This latest mitochondrial editing approach is still quite a ways away from being used in clinics and hospitals. Researchers are currently using the technique in animal models similar to those of the human mitochondrial genome to test for any potential side effects. Since Ddda is easy to synthesize from bacteria, once the process becomes widely used in the medical field, price should not be too much of an issue. The potential prospects for the Ddda enzyme are promising and many scientists are looking towards Ddda to help cure genetic mitochondrial diseases in the future due to the precise modifications it allows scientists to make.

Article Link: https://www.nature.com/articles/d41586-020-02054-5

Related Link: https://pubmed.ncbi.nlm.nih.gov/15720251/