Prime editing pileup; plus Travera, Emulate, bitBiome and more

A team led by David Liu at the  Broad Institute of MIT and Harvard showed DNA mismatch repair (MMR) inhibits prime editing efficiency and precision. Prime editing, a “search-and-replace” genome editing method first detailed by Liu in Nature in 2019, finds the precise place in the genome to edit and replaces the segment of faulty DNA with a correct copy without making cuts. The Cell paper authors engineered prime editing systems, PE4 and PE5, that transiently express an MMR-inhibiting protein and enhance the efficiency of substitution, small deletion and small insertion prime edits in synergy with engineered prime editing guide RNAs.

A pair of papers published Thursday in Nature Biotechnology outline new versions of prime editing that enable large deletions using a pair of prime editing guide RNAS that target complementary DNA strands. The methods overcome current gene editing limits, which struggle to accurately or efficiently make edits larger than 100 base pairs...