Genetic recombination of bacteriophage lambda DNAs in Xenopus oocytes

Pairs of genetically marked bacteriophage lambda DNAs have been injected into Xenopus laevis oocyte nuclei. After suitable incubation, DNA was recovered and packaged into phage particles in vitro. When these were plated onto a selective host, phage recombinant for parental markers were observed. Recombination was dependent on both parents being present in the same oocyte nucleus and was roughly proportional to the physical separation of the markers. Thus, the oocytes appear to contain the machinery necessary for performing typical genetic recombination. This system offers a great deal of scope and flexibility for future studies of recombination mechanisms at the molecular level in vertebrates.