New “Prime Editing” Gene Editing Tool
A new gene editing tool could fix harmful genetic mutations. Scientists from Harvard University and the Massachusetts Institute of Technology have developed a new method of editing DNA called Prime Editing which combines CRISPR-cas9 with a reverse transcriptase enzyme.
According to a study published in the Journal Nature, the CRISPR-cas9 is used to make one DNA strand while the enzyme generates a new DNA strand which is inserted into the original DNA strand. Another reverse transcriptase enzyme then guides the CRISPR-cas9 to nick the other DNA strand. The strand is repaired as the enzyme replicates gene edits over from the new DNA strand producing a fully editing DNA strand.
According to a Harvard news release, Prime Editing can also be used to replace one DNA letter with another and could correct up to 89% of genetic mutations. In the study, researchers explained that they used prime editing to make more than 175 edits in human cells in a laboratory and successfully corrected sickle-cell anemia and Tay-Sachs disease. According to the Harvard news release, CRISPR-cas9, if used by itself, isn’t as precise as Prime Editing and could lead to mismatched DNA strands that either include extra DNA code or are missing a certain genetic code. The authors of the study concluded by saying they will investigate the effects of Prime Editing on human cells and will continue to test Prime Editing.