1887

Abstract

Summary: The sensitivity to γ-radiation of the chromosome of a Hfr strain of was six times greater when assayed by donor ability in conjugation than when assayed by survival in unmated bacteria. With a Hfr strain sensitivities were comparable when assayed by the two methods, and were similar to the sensitivity of donor ability in the strain. We suggest that the greater resistance of survival in the strain may be due to a post-replicational repair process which does not occur in the strain and which is prevented from occurring when a chromosome of either strain is involved in conjugation. When a Hfr and a F- strain were given 8·5 krads γ-radiation, enough to inhibit completely normal DNA synthesis, the DNA synthesis associated with conjugation still occurred. This suggests that the lesions which prevent recombinant formation may act not by inhibiting chromosome transfer, but by affecting a later stage in the process of integration.

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/content/journal/micro/10.1099/00221287-67-1-63
1971-07-01
2021-10-28
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References

  1. Barbour S. D. 1967; Effect of nalidixic acid on conjugational transfer and expression of episomal lac genes in Escherichia coli k 12. Journal of Molecular Biology 28:373–376
    [Google Scholar]
  2. Bresler S. E., Lanzov V. A., Lukjaniec-Blinkova A. A. 1968; On the mechanism of conjugation in Escherichia coli k 12. Molecular and General Genetics 102:269–284
    [Google Scholar]
  3. Clark A. J., Margulies A. D. 1965; Isolation and characterization of recombination-deficient mutants of Ecoli k 12. Proceedings of the National Academy of Sciences of the United States of America 53:451–459
    [Google Scholar]
  4. Ganesan A. K., Smith K. C. 1969; Dark recovery processes in Escherichia coli irradiated with ultraviolet light. II. Effect of uvr genes on liquid-holding recovery. Journal of Bacteriology 97:1129–1133
    [Google Scholar]
  5. Greenberg J., Green M. H. L., Bar-Nun N. 1970; The effect of u.v. irradiation on the capacity of an Hfr RecA strain of Escherichia coli to act as donor. Molecular and General Genetics 107:209–214
    [Google Scholar]
  6. Haas F. L., Doudney C. O. 1957; A relation of nucleic acid synthesis to radiation-induced mutation frequency in bacteria. Proceedings of the National Academy of Sciences of the United States of America 43:871–883
    [Google Scholar]
  7. Howard-Flanders P., Rupp W. D., Wilkins B. M., Cole R. S. 1968; DNA replication and recombination after u.v. irradiation. Cold Spring Harbor Symposia on Quantitative Biology 33:195–205
    [Google Scholar]
  8. Howard-Flanders P., Theriot L. 1966; Mutants of Escherichia coli defective in DNA repair and in genetic recombination. Genetics, Princeton 53:1137–1150
    [Google Scholar]
  9. Kapp D. S., Smith K. C. 1970; Repair of radiation-induced damage in Escherichia coli. II. Effect of rec and uvr mutations on radiosensitivity, and repair of X-ray-induced single-strand breaks in deoxyribonucleic acid. Journal of Bacteriology 103:49–54
    [Google Scholar]
  10. Marcovich H. 1961; Recherche sur le mécanisme de Paction létale des rayons X chez Escherichia coli k 12 au moyen de la recombinaison génétique. Annales de l’Institut Pasteur, Paris 101:660–676
    [Google Scholar]
  11. Rupp W. D., Howard-Flanders P. 1968; Discontinuities in the DNA synthesized in an excision-defective strain of Escherichia coli following ultraviolet irradiation. Journal of Molecular Biology 31:291–304
    [Google Scholar]
  12. Smith K. C., Meun D. H. C. 1970; Repair of radiation-induced damage in Escherichia coli. I. Effect of rec mutations on post-replication repair of damage due to ultraviolet radiation. Journal of Molecular Biology 51:459–472
    [Google Scholar]
  13. Wood T. H., Walmsley R. H. 1969; Conjugation in Escherichia coli k 12 and its modification by irradiation. Biophysical Journal 9:391–420
    [Google Scholar]
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