Abstract
Repair of genetic damage in Neurospora has been studied using a procedure in which one strain is exposed to a potentially lethal dose of UV before being joined in a heterokaryon with an undamaged strain. We have monitored the ability of the second strain to rescue the first. The extent of rescue is greatly enhanced when the rescuing strain has itself received a small, nonlethal dose of UV, thus demonstrating an inducible repair system.—The experiment was modified by substituting X rays or nitrous acid for UV as either the damaging agent or the inducing agent. In every combination, induced rescue was observed.——Three repair-deficient mutants (uvs-2, uvs-3 and uvs-6) were substituted for wild type (uvs+) as the rescuing component to find out whether any of them lacked the inducible repair system. Both uvs-2 and uvs-6 demonstrated inducible repair; uvs-3 showed none, but gave a high level of repair without induction, suggesting that it is a regulation (derepressed) mutant of an inducible repair system.
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Selected References
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- Auerbach C., Ramsay D. Analysis of a case of mutagen specificity in Neurospora crassa. IV. Interactions between UV and three chemical mutagens. Mol Gen Genet. 1972;117(1):1–13. doi: 10.1007/BF00268831. [DOI] [PubMed] [Google Scholar]
- Cox B., Game J. Repair systems in Saccharomyces. Mutat Res. 1974 Aug;26(4):257–264. doi: 10.1016/s0027-5107(74)80023-0. [DOI] [PubMed] [Google Scholar]
- Käfer E. Mutagen sensitivities and mutator effects of MMS-sensitive mutants in Neurospora. Mutat Res. 1981 Jan;80(1):43–64. doi: 10.1016/0027-5107(81)90176-7. [DOI] [PubMed] [Google Scholar]
- Lawrence C. W., Christensen R. UV mutagenesis in radiation-sensitive strains of yeast. Genetics. 1976 Feb;82(2):207–232. doi: 10.1093/genetics/82.2.207. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leaper S., Resnick M. A., Holliday R. Repair of double-strand breaks and lethal damage in DNA of Ustilago maydis. Genet Res. 1980 Jun;35(3):291–307. doi: 10.1017/s0016672300014154. [DOI] [PubMed] [Google Scholar]
- Painter R. B. Does ultraviolet light enhance postreplication repair in mammalian cells? Nature. 1978 Sep 21;275(5677):243–245. doi: 10.1038/275243a0. [DOI] [PubMed] [Google Scholar]
- Schroeder A. L. Ultraviolet-sensitive mutants of Neurospora. II. Radiation studies. Mol Gen Genet. 1970;107(4):305–320. doi: 10.1007/BF00441193. [DOI] [PubMed] [Google Scholar]
- Shelby M. D., Stine G. J., De Serres F. J. Gamma-ray inactivation of conidia from heterokaryons of Neurospora crassa containing UV-sensitive mutations. Mutat Res. 1975 May;28(2):147–154. doi: 10.1016/0027-5107(75)90091-3. [DOI] [PubMed] [Google Scholar]
- Stadler D. R., Smith D. A. A new mutation in Neurospora for sensitivity to ultraviolet. Can J Genet Cytol. 1968 Dec;10(4):916–919. doi: 10.1139/g68-115. [DOI] [PubMed] [Google Scholar]
- Stadler D., Crane E. Analysis of lethal events induced by ultraviolet in a heterokaryon of Neurospora. Mol Gen Genet. 1979 Mar 9;171(1):59–68. doi: 10.1007/BF00274015. [DOI] [PubMed] [Google Scholar]
- Weigle J. J. Induction of Mutations in a Bacterial Virus. Proc Natl Acad Sci U S A. 1953 Jul;39(7):628–636. doi: 10.1073/pnas.39.7.628. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Witkin E. M. The mutability toward ultraviolet light of recombination-deficient strains of Escherichia coli. Mutat Res. 1969 Jul-Aug;8(1):9–14. doi: 10.1016/0027-5107(69)90135-3. [DOI] [PubMed] [Google Scholar]
- Worthy T. E., Epler J. L. Biochemical basis of radiation-sensitivity in mutants of Neurospora crassa. Mutat Res. 1973 Aug;19(2):167–173. doi: 10.1016/0027-5107(73)90075-4. [DOI] [PubMed] [Google Scholar]