Conjugation in Escherichia coli: A study of recombination and the fate of donor DNA at the level of the zygote

Abstract

We have developed an experimental system for studying concomitantly the fate of the donor DNA and the process of recombination after conjugation in Escherichia coli. We used a set of Hfr and F^- strains carrying complementing lacZ mutations. Expression of the lacZ allele on the chromosomal fragment derived from the donor results in the formation of heat sensitive β-galactosidase by complementation. By intragenic recombination between the two lacZ mutations a lacZ ⁺ gene may be formed, and wild type β-galactosidase will be synthesized subsequently. So the assay of heat sensitive and wild type β-galactosidase enabled us to follow respectively the fate of the donor DNA and the recombination process.