Summary
A UV-revertible mutant of the nar1 structural gene for nitrate reductase was isolated in wildtype (nar + nir +) Ustilago maydis. It proved to be vigorously revertible by gamma rays as well. Genetic analysis revealed that the strain carried a single, nonleaky, recessive allele (nar1-m) with an unusually high spontaneous reversion rate (∼3×10-5/div.). Reliable reversion frequencies were determined with a special agar medium that reduced the normally high level of residual growth observed on nitrate minimal agar. Radiation-induced reversion frequencies in the homozygous diploid were approximately twice those in the hapliod. Following crosses to wild type, two revertants (one spontaneous and one UV-induced) were found to map at nar1. Although the molecular basis of nar1-m reversion is not known, available data suggest that some form of point mutation is involved.
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References
Barnett, W.E., de Serres, F.J.: Fixed genetic instability in Neurospora crassa. Genetics 48, 717–723 (1963)
von Borstel, R.C., Quah, Siew-Keen, Steinberg, C.M., Flury, F., Gottlieb, D.J.C.: Mutants of yeast with enhanced spontaneous mutation rates. Genetics, Suppl. 73, 141–151 (1973)
Britten, R.J., Davidson, E.H.: Gene regulation for higher cells: A theory. Science 165, 349–357 (1969)
Daniell, E., Roberts, R., Abelson, J.: Mutations of the lactose operon caused by bacteriophage mu. J. molec. Biol. 69, 1–8 (1972)
Fabre, F.: UV-sensitivity of the wild-type and different UVS mutants of Schizosaccharomyces pombe. Influence of growth stages and DNA content of the cells. Mutation Res. 10, 415–426 (1970)
Fincham, J.R.S.: Localized instabilities in plants-a review and some speculations. Genetics, Suppl. 73, 195–205 (1973)
Fincham, J.R.S.: Mutable genes in the light of Callan's masterslave hypothesis. Nature (Lond.) 215, 864–866 (1967)
Green, M.M.: Some observations and comments on mutable and mutator genes in Drosophila. Genetics, Suppl. 73, 187–194 (1973)
Holliday, R.: Induced mitotic crossing-over in relation to genetic replication in synchronously dividing cells of Ustilago maydis. Genet. Res. 6, 104–120 (1965)
Holliday, R.: Studies on mitotic gene conversion in Ustilago. Genet. Res. 8, 323–337 (1966)
Holliday, R.: Altered recombination frequencies in radiation sensitive strains of Ustilago. Mutation Res. 4, 275–288 (1967)
Holliday, R.: Biochemical measure of the time and frequency of radiation-induced allelic recombination in Ustilago. Nature (Lond.) New Biol. 232, 233–236 (1971)
Holliday, R.: Ustilago maydis. In: Handbook of genetics (R.C. King, ed.), Vol. 1, pp. 575–595, New York: Plenum Press 1974
Holliday, R., Holloman, W.K., Banks, G.R., Unrau, P., Pugh, J.E.: Genetic and biochemical studies of recombination in Ustilago maydis. In: Mechanisms in recombination (R.F. Grell, ed.), pp. 239–262. New York: Plenum Press 1974
Kimball, R.F., Setlow, J.K.: Mutation fixation in MNNG-treated Haemophilus influenzae as determined by transformation. Mutation Res. 22, 1–14 (1974)
Laskowski, W.: Inaktivierungsversuche mit homozyoten Hefestämmen verschiedenen Plodilgrades. Z. Naturforsch. 15b, 495–506 (1960)
Lawrence, C.W., Christensen, R.: UV mutagenesis in radiation sensitive strains of yeast. Genetics 82, 207–232 (1976)
Lawrence, C.W., Stewart, J.W., Sherman, F., Christensen, R.: Specificity and frequency of ultraviolet-induced reversion of an iso-1-cytochrome c ochre mutant in radiation-sensitive strains of yeast. J. molec. Biol. 85, 137–162 (1974)
Lea, D.E., Coulson, C.A.: The distribution of the numbers of mutants in bacterial populations. J. Genet. 49, 264–285 (1949)
Lemontt, J.F.: Genes controlling ultraviolet mutability in yeast. Genetics, Suppl 73, 153–159 (1973)
Lemontt, J.F.: Induced mutagenesis in Ustilago maydis: II. An in vivo biochemical assay. Molec. gen. Genet. 145, 133–143 (1976)
Lewis, C.M., Fincham, J.R.S.: Regulation of nitrate reductase in the basidiomycete Ustilago maydis. J. Bact. 103, 55–61 (1970a)
Lewis, C.M., Fincham, J.R.S.: Genetics of nitrate reductase in Ustilago maydis. Genet. Res. 16, 151–163 (1970b)
Luria, S.E., Delbrück, M.: Mutations of bacteria from virus sensitivity to virus resistance. Genetics 28, 491–511 (1943)
McClintock, B.: Controlling elements and the gene. Cold. Spr. Harb. Symp. quant. Biol. 21, 197–216 (1956)
Mortimer, R.K.: Radiobiological and genetic studies on a polyploid series (haploid to hexaploid) of Saccharomyces cerevisiae. Radiation Res. 9, 312–326 (1958)
Moustacchi, E., Enteric, S.: Differential “Liquid Holding Recovery” for the lethal effect and cytoplasmic “Petite” induction by UV light in Saccharomyces cerevisiae. Molec. gen. Genet. 109, 69–83 (1970)
Nakai, S., Matsumoto, S.: Two types of radiation-sensitive mutants in yeast. Mutation Res. 4, 129–136 (1967)
Nasim, A.: UV-induced replicating instability in Schizosaccharomyces pombe. Mutation Res. 22, 25–31 (1974)
Peterson, P.A.: Controlling elements and mutable loci in maize: their relationship to bacterial episomes. Genetica 41, 33–56 (1970)
Resnick, M.A., Holliday, R.: Genetic repair and the synthesis of nitrate reductase in Ustilago maydis after UV irradiation. Molec. gen. Genet. 111, 171–184 (1971)
Sherman, F., Stewart, J.W., Parker, J.H., Putterman, G.J., Agrawl, B.B.L., Margoliash, E.: The relationship of gene structure and protein structure of iso-1-cytochrome c from yeast. Symp. Soc. exp. Biol. 24, 85–107 (1970)
Unrau, P., Holliday, R.: Recombination during blocked chromosome replication in temperature-sensitive strains of Ustilago maydis. Genet. Res. 19, 145–155 (1972)
Wallace, B., Kass, T.L.: On the structure of gene control regions. Genetics 77, 541–558 (1974)
Waters, R., Moustacchi, E.: Dose dependence of the excision of ultraviolet-induced pyrimidine dimers from nuclear deoxyribonucleic acids of haploid and diploid Saccharomyces cerevisiae. J. Bact. 121, 901–906 (1975)
Witkin, E.M.: Ultraviolet-induced mutation and DNA repair. Ann. Rev. Genet. 3, 525–552 (1969)
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Communicated by Ch. Auerbach
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Lemontt, J.F. Induced mutagenesis in Ustilago maydis . Molec. Gen. Genet. 145, 125–132 (1976). https://doi.org/10.1007/BF00269584
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DOI: https://doi.org/10.1007/BF00269584