Spontaneous and induced homologous recombination betweenlacZ chromosomal direct repeats in CV-1 cells

Abstract
AlacZ substrate for intrachromosomal homologous recombination was generated at a specific site within the genome of CV-1 cells by FLP recombinase-mediated gene targeting. A histochemical stain was used to detect cells that contained recombinedlacZ genes. The spontaneous rate of homologous recombination was approximately 1×10−5 events per cell generation. Recombi nation was induced 30-fold in cells following exposure to mitomycin C (MMC) and by serum starvation. These results demonstrate the utility of the FLP recombinase in modifying the genome of mammalian cells in a predetermined manner and show that homologous recombination between direct repeats is increased in cells as a result of the withdrawal of serum growth factors.