Gene editing also refers to purposefully changing a gene’s DNA sequence. It is a potent tool for studying mutations leading to diseases and changing an individual’s DNA for therapeutic reasons. A novel method has been developed by researchers that could help develop safe and more efficient gene therapies. The study is a huge advancement for Gene Therapy Market and could be regarded as a technical advance as it can accelerate the production of disease models in animals. Further, it could technically open up a new brand of methodology for correcting disease-causing mutations.
The team’s main objective was to raise the efficiency of the gene-editing process. To achieve this, they initially thought that adding a DNA repair protein, known as RAD51, to a standard mixture of CRISPR gene editing tools could help the chances that a cell (here a fertilized mouse egg or one-cell embryo was used) would undergo the desired genetic change. To test their hypothesis, researchers measured the rate at which they inserted (“knock-in”) a mutation in the gene Chd2(associated with autism).
They discovered that the overall proportion of embryos that were correctly edited remained unchanged. However, interestingly their experiments also revealed a considerably higher percentage carried the desired gene edit on both chromosomes. Thus, tests with a different gene brought on the same unexpected outcome. Next, the team tried to understand the mechanism through which RAD51 improves gene editing. Their hypothesis was that RAD51 engages an IHR (Interhomolog Repair) process wherein a DNA break on one chromosome is repaired with the help of a second copy of the chromosome (received from the other parent), similar to the template.
The team discovered that control embryos injected along with CRISPR alone did not show IHR repair much. But if RAD51 was included, then the statistics improved. Hence, the numbers of embryos in which the CRISPR-targeted genes were edited to imitate the uncut chromosome increased. At last, researchers tried to identify additional DNA repair-associated proteins that can help stimulate IHR. Further, they also looked into those which not only promote high levels of IHR but also suppress errors in the DNA repair process. These additional experiments in which the team examined the genomic features of IHR events empowered them with deeper insight into the mechanism of IHR. Moreover, it suggested ways in which gene therapies can be made safer through techniques.