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Studies on mitotic gene conversion in Ustilago

Published online by Cambridge University Press:  14 April 2009

Robin Holliday
Affiliation:
John Innes Institute, Bayfordbury, Hertford, Herts.

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In order to develop a system for the study of the mechanism of intragenic recombination in Ustilago, mutants lacking nitrate reductase activity were isolated, and five alleles were combined in pairs in ten vegetative heteroallelic diploids. The diploids have the mutant phenotype, i.e. inability to utilize nitrate as sole source of nitrogen, but they will recombine to produce wild-type cells much more frequently than the back-mutation rates of haploids or homoallelic diploids. The spontaneous rate of recombination can be enormously increased by low doses of UV light, particularly if treatment is during the period of DNA synthesis in the mitotic cycle. By means of half-tetrad analysis it has been shown that this process of intragenic recombination, as in other fungi, is due to gene conversion rather than reciprocal exchange. It has also been shown that the frequency of UV-induced conversion under standard conditions gives a rough measure of the distance between two mutant sites, since it was possible to use these frequencies to make a linear fine structure map of the gene. These results are discussed in relation to a hybrid DNA model for gene conversion slightly modified from that previously suggested for meiotic recombination.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1966

References

REFERENCES

Bodmer, W. F. (1965). Recombination and integration in Bacillus subtilis transformation: involvement of DNA synthesis. J. molec. Biol. 14, 534557.Google Scholar
Boyce, R. P. & Howard-Flanders, P. (1964). Release of ultraviolet-induced thymine dimers from DNA in E. coli K-12. Proc. natn. Acad. Sci. U.S.A. 51, 293300.CrossRefGoogle Scholar
Fogel, S. & Hurst, D. D. (1963). Coincidence relations between gene conversion and mitotic recombination in Saccharomyces. Genetics, 48, 321328.Google Scholar
Gallant, J. & Spotswood, T. (1965). The recombinagenic effect of thymidylate starvation in Escherichia coli merodiploids. Genetics, 52, 107118.CrossRefGoogle Scholar
Holliday, R. (1961 a). The genetics of Ustilago maydis. Genet. Res. 2, 204230.Google Scholar
Holliday, R. (1961 b). Induced mitotic crossing-over in Ustilago maydis. Genet. Res. 2, 231248.CrossRefGoogle Scholar
Holliday, R. (1962). Selection of auxotrophs by inositol starvation in Ustilago maydis. Microb. Genet. Bull. 18, 2830.Google Scholar
Holliday, R. (1964). A mechanism for gene conversion in fungi. Genet. Res. 5, 282304.CrossRefGoogle Scholar
Holliday, R. (1965 a). Induced mitotic crossing-over in relation to genetic replication in synchronously dividing cells of Ustilago maydis. Genet. Res. 6, 104120.Google Scholar
Holliday, R. (1965 b). Radiation sensitive mutants of Ustilago maydis. Mutation Res. 2, 557559.Google Scholar
Hurst, D. D. & Fogel, S. (1964). Mitotic recombination and heteroallelic repair in Saccharo-myces cerevisiae. Genetics, 50, 435458.CrossRefGoogle Scholar
Jansen, G. J. O. (1964). UV-induced mitotic recombination in the paba 1 region of Aspergillus nidulans. Genetica, 35, 127131.Google Scholar
Kakab, S. N. (1963). Allelic recombination and its relation to recombination of outside markers in yeast. Genetics, 48, 957966.Google Scholar
Lacks, S. (1966). Integration efficiency and genetic recombination in pneumococcal transformation. Genetics, 53, 207235.CrossRefGoogle ScholarPubMed
Leupold, U. (1958). Studies on recombination in Schizosaccharomyces pombe. Cold Spring Harb. Symp. quant. Biol. 23, 161170.CrossRefGoogle ScholarPubMed
Lissouba, P., Mousseau, J., Rizet, G. & Rossignoi, J. L. (1962). Fine structure of genes in the Ascomycete Ascobolus immersus. Adv. Genet. 11, 343380.Google Scholar
Manney, T. R. & Mortimer, R. K. (1964). Allelic mapping in yeasts using X-ray induced mitotic reversion. Science, N.Y. 143, 581582.Google Scholar
Pateman, J. A., Cove, D. J., Rever, B. M. & Roberts, D. B. (1964). A common co-factor for nitrate reductase and xanthine dehydrogenase which also regulates the synthesis of nitrate reductase. Nature, Lond. 201, 5860.Google Scholar
Pritchard, R. H. (1955). The linear arrangement of a series of alleles of Aspergillus nidulans. Heredity, Lond. 9, 343371.CrossRefGoogle Scholar
Pritchard, R. H. (1960). Localised negative interference and its bearing on models of gene recombination. Genet. Res. 1, 124.CrossRefGoogle Scholar
Putrament, A. (1964). Mitotic recombination in the paba 1 cistron of Aspergillus nidulans. Genet. Res. 5, 316327.Google Scholar
Roman, H. L. (1956). Studies of gene mutation in Saccharomyces. Cold Spring Harb. Symp. quant. Biol. 21, 175183.Google Scholar
Roman, H. L. (1958). Sur les recombinaisons non reciproques chez Saccharomyces cereviseae et sur les problémes posés par ces phenoménes. Annls. Génét. 1, 1117.Google Scholar
Roman, H. L. & Jacob, F. (1958). A comparison of spontaneous and ultraviolet-induced allelic recombination with reference to the recombination of outside markers. Cold Spring. Harb. Symp. quant. Biol. 23, 155160.Google Scholar
Roper, J. A. & Pritchard, R. H. (1955). Recovery of complementary products of mitotic crossing-over. Nature, Lond. 175, 639.Google Scholar
Setlow, R. B. & Carrier, W. L. (1964). The disappearance of thymine dimers from DNA: An error correcting mechanism. Proc. natn. Acad. Sci. U.S.A. 51, 226231Google Scholar
Whitehouse, H. L. K. & Hastings, P. J. (1965). The analysis of genetic recombination on the polaron hybrid DNA model. Genet. Res. 6, 2792.CrossRefGoogle ScholarPubMed