Fig 4.
Effect of the orientation of the neo reporter gene on ssODN-mediated gene targeting. (A) Fwd and Rev neo cell lines contain a single copy of the mutant neo gene integrated in opposite directions at the same chromosomal position in the Rosa26 locus of Msh2-deficient ES cells. The direction of the Rosa26 promoter is indicated by an arrow. (B) Correction of the neo gene by sense ssODNs (black bars) or antisense ssODNs (white bars) in the Fwd and Rev neo cell lines. Targeting efficiency is the number of G418-resistant colonies per 105 cells that were plated after ssODN exposure. Error bars represent the S.D. of at least three independent experiments.