Summary
The ability of a recA Hfr strain of Escherichia coli to form colonies is extremely sensitive to inhibition by ultraviolet light (Fig. 2). Furthermore, in this strain the synthesis of DNA is stopped completely by a dose of 385 ergs/mm2 of UV (Fig. 3). Nevertheless, the ability of this recA Hfr strain to act as a donor in sexual recombination was no more sensitive to UV than that of a wild type donor (Fig. 1). Furthermore, when irradiated and mated with a recA female, in which DNA synthesis was also inhibited by UV (Fig. 3), there was a net synthesis of DNA as measured by the incorporation of C14 thymidine (Fig. 4). By using nalidixic acid resistant recA donors and recipients in all combinations, irradiating with UV and treating with nalidixic acid during mating, it is shown that DNA was synthesized by the donor (Fig. 5). It is concluded that synthesis of DNA directed by the sex factor during mating in a recA donor is not as sensitive to inhibition by UV as normal DNA synthesis in a recA donor.
Similar content being viewed by others
References
Bonhoeffer, F.: DNA transfer and DNA synthesis during bacterial conjugation. Z. Vererbungsl. 98, 141–149 (1966).
Bresler, S. E., Lanzov, V. A., Lukjaniec-Blinkova, A. A.: On the mechanism of conjugation in Escherichia coli K-12. Molec. Gen. Genetics 102, 269–284 (1968).
Budman, D. R., Pardee, A. B.: Thymidine and thymine incorporation into deoxyribonucleic acid: inhibition and repression by uridine of thymidine phosphorylase of Escherichia coli. J. Bact. 94, 1546–1550 (1967).
Clark, A. J., Chamberlin, M., Boyce, R. P., Howard-Flanders, P.: Abnormal metabolic response to ultraviolet light of a recombination deficient mutant of Escherichia coli K-12. J. molec. Biol. 19, 442–454 (1966).
—, Margulies, A. D.: Isolation and characterization of recombination-deficient mutants of Escherichia coli K-12. Proc. nat. Acad. Sci. (Wash.) 53, 451–459 (1965).
Donch, J., Greenberg, J.: Genetic analysis of lon mutants of strain K-12 of Escherichia coli. Molec. Gen. Genetics 103, 105–115 (1968a).
—: Ultraviolet sensitivity gene of Escherichia coli B. J. Bact. 95, 1555–1559 (1968b).
Godson, G. N., Sinsheimer, R. L.: Lysis of Escherichia coli with a neutral detergent. Biochim. biophys. Acta (Amst.) 149, 476–488 (1967).
Goss, W. A., Deitz, W. H., Cook, T. M.: Mechanism of action of nalidixic acid on Escherichia coli. II. Inhibition of deoxyribonucleic acid synthesis. J. Bact. 89, 1068–1074 (1965).
Horii, Z. I., Suzuki, K.: Degradation of the DNA of Escherichia coli K-12 Rec− (JC 1569b) after irradiation with ultraviolet light. Photochem. Photobiol. 8, 93–105 (1968).
Howard-Flanders, P., Rupp, W. D., Wilkins, B. M., Cole, R. S.: DNA replication and recombination after UV irradition. Cold Spr. Harb. Symp. quant. Biol. 33, 195–205 (1968).
Ohki, M., Tomizawa, J.: Asymetric transfer of DNA strands in bacterial conjugation. Cold Spr. Harb. Symp. quant. Biol. 33, 651–658 (1968).
Willets, N. S., Clark, A. J.: Characterization of some multiply recombination-deficient strains of Escherichia coli. J. Bact. 100, 231–239 (1969).
Author information
Authors and Affiliations
Additional information
Communicated by E. Witkin
Rights and permissions
About this article
Cite this article
Greenberg, J., Green, M.H.L. & Bar-Nun, N. The effect of UV irradiation on the capacity of an Hfr recA strain of Escherichia coli to act as donor. Molec. Gen. Genet. 107, 209–214 (1970). https://doi.org/10.1007/BF00268695
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00268695