Better Gene Editing than CRISPR
George Church describes going beyond cutting DNA to precise editing.
1. Phage Integrases (Protein and DNA)
2. TAL Deaminases (custom Protein)
3. Chemical Targeting (custom polymer)
4. lambda (λ)-red recombinase (Custom DNA)
DNA-based target recognition
For DNA-based target recognition systems, the two major approaches, multiplex automated genome engineering (MAGE) using λ-red recombination and conjugative assembly genome engineering (CAGE) have been widely used in prokaryotes and demonstrated a high degree of multiplexability. Briefly, the λ-red system, similar to recET, originates from phage and when imported into bacterial cells, can stimulate high levels of recombination in the presence of homologous DNA. Although the machinery used in these approaches has not been fully optimized yet for eukaryotic cells, some conjugal transfer has been demonstrated and use of an optimized version of Redβ in human cells has yielded limited success. Moreover, these technologies can be used to edit and propagate large pieces of DNA in bacteria for eventual use as donor DNA molecules for HR in human cells.