“Recombinase”-independent recombineering


A system for generating ssDNA recombinants has been developed by Bryan Swingle and colleagues. Although not technically “recombineering" as no known bacteriophage functions are involved, similar rules apply. When high concentrations of oligos are transformed into a cell lacking a known recombineering system, ssDNA recombinants are found at a frequency of ~104/108 viable cells. Lagging-strand oligos that avoid the MMR system result in the highest efficiencies. This (known) recombinase-independent ssDNA recombination has so far been demonstrated in P. syringae pv, E. coli, S. enterica, S. flexneri and Y. pseudotuberculosis, and L. pneumophila. It provides another option for creating mutations in organisms where recombineering systems have not yet been developed.