Transfer and incorporation of genes controlling beta-D-galactosidase synthesis from Hfr and F' donors of Escherichia coli.

Ganesan, Ann K. (Syntex Institute of Molecular Biology, Palo Alto, Calif.), and Boris Rotman. Transfer and incorporation of genes controlling beta-d-galactosidase synthesis from Hfr and F' donors of Escherichia coli. J. Bacteriol. 92:1378-1382. 1966.-Comparisons were made between Hfr(1) and F(13) donors with respect to the frequency of transfer and incorporation of genes controlling beta-d-galactosidase synthesis. The Hfr(1) donor transfers these genes as part of the chromosome, and the F(13) donor transfers them by F-duction. The criterion used for gene transfer was the acquisition by recipient cells of the ability to synthesize the enzyme, beta-d-galactosidase, measured by fluorogenic assays at the single-cell level. The criterion for incorporation was the formation of lac(+) recombinant colonies. It was found that the two types of donor showed the same frequency of gene transfer, but the probability of incorporation was 10-fold higher in F(13) matings than in Hfr(1) matings. In the former, between 46 and 97% of the merozygotes produced recombinant colonies; in the latter, 2 to 6% did so.