CRISPR Rules When It Obeys the CRISPR Rules
When the gene-editing system known as CRISPR is used, DNA breaks occur fairly reliably, but not DNA repairs—specifically, the repairs that are supposed to insert synthetic donor DNA. But repairs may be more likely to “stick,” say Johns Hopkins scientists, if donor DNA is properly designed. The scientists suggest that homology-directed repair, the usual mechanism for knockin of new genetic material, is more efficient if a few design rules are followed. In a nutshell, the rules are: Use donor DNA that’s linear, not circular. Keep homology arms (sticky single-stranded overhangs) fairly short, about 35 nucleotides in length. To arrive at these rules, a Johns Hopkins team led by Geraldine Seydoux, Ph.D., inserted various combinations of donor DNA into human embryonic kidney cells, known for their ability to grow well and for their frequent use in cancer research. The scientists used donor DNA with ...
Original Article: CRISPR Rules When It Obeys the CRISPR Rules
