Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-25T15:20:12.816Z Has data issue: false hasContentIssue false

Altered instability due to genetic changes in a duplication strain of Aspergillus nidulans

Published online by Cambridge University Press:  14 April 2009

J. L. Azevedo
Affiliation:
Microbial Genetics Sector, Institute of Genetics, 13400 – Piracicaba, São Paulo, Brazil
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Strains of Aspergillus nidulans with a duplicate segment are mitotically unstable; they produce phenotypically improved variants following deletions in either duplicate segment, and morphologically deteriorated types. The number of variants produced is characteristic of each duplication strain under the same conditions. After ultraviolet treatment two variants, one more stable and the other less stable than the original strain, were selected. Genetic analysis showed that the increased instability in the less stable variant was due to a translocation involving linkage groups V and VIII. The increased stability of the more stable variant was due to a recessive factor (stf1) located in linkage group VIII. In the homozygous condition this factor also reduces the number of sectors in a diploid strain. The possible genetic mechanisms explaining the instability alterations are discussed.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1975

References

REFERENCES

Azevedo, J. L. (1971). Mitotic non-conformity in Aspergillus nidulans. Ph.D. thesis, University of Sheffield.Google Scholar
Azevedo, J. L. & Roper, J. A. (1970). Mitotic non-conformity in Aspergillus: successive and transposable genetic changes. Genetical Research 16, 7993.CrossRefGoogle ScholarPubMed
Ball, C. (1967). Chromosome instability related to gene suppression in Aspergillus nidulans. Genetical Research 10, 173183.CrossRefGoogle ScholarPubMed
Ball, C. & Azevedo, J. L. (1974). The applied significance of genetic instability in parasexual fungi. Proceedings of the 2nd International Symposium in Genetics of Industrial Microorganisms. New York: Academic Press. (In the Press.)Google Scholar
Bainbridge, B. W. & Roper, J. A. (1966). Observations on the effects of a chromosome duplication in Aspergillus nidulans. Journal of General Microbiology 42, 417424.CrossRefGoogle ScholarPubMed
Burr, K. W., Palmer, H. M. & Roper, J. A. (1971). Mitotic non-conformity in Aspergillus nidulans: The effect of reduced DNA repair. Heredity 27, 487.Google Scholar
Clutterbuck, A. J. (1970 a). A variegated position effect in Aspergillus nidulans. Genetical Research 16, 303316.CrossRefGoogle ScholarPubMed
Clutterbuck, A. J. (1970 b). Aspergillus symbols, locus letters and allele numbers. Aspergillus Newsletter 11, 2533.Google Scholar
Cooke, P., Roper, J. A. & Watmough, W. A. (1970). Trypan blue induced deletions in duplications strains of Aspergillus nidulans. Nature 226, 276277.CrossRefGoogle ScholarPubMed
Forbes, E. (1959). Use of mitotic segregation for assigning genes to linkage groups in Aspergillus nidulans. Heredity 13, 6780.CrossRefGoogle Scholar
Jansen, G. J. O. (1970). Survival of uvs B and uvs C mutants of Aspergillus nidulans after U.V.-irradiation. Mutation Research 10, 2132.CrossRefGoogle Scholar
Lee, Y. T. & Nga, B. H. (1974). Mitotic stability of a duplication in Aspergillus nidulans. Genetics 77, 3839.Google Scholar
Lhoas, P. (1961). Mitotic haploidization by treatment of Aspergillus niger diploids with p-fluorophenylalanine. Nature 190, 744.CrossRefGoogle Scholar
Lieber, M. M. (1975). Environmental and genetic factors affecting instability at mitosis in Aspergillus nidulans. Aspergillus Newsletter 12, 2627.Google Scholar
McCully, K. S. & Forbes, E. (1965). The use of p-fluorophenylalanine with ‘master-strains’ of Aspergillus nidulans for assigning genes to linkage groups. Genetical Research 6, 352359.CrossRefGoogle ScholarPubMed
Morpurgo, G. (1961). Somatic segregation induced by p-fluorophenylalanine, Aspergillus Newsletter 2, 10.Google Scholar
Nga, B. H. & Roper, J. A. (1968). Quantitative intrachromosomal change arising at mitosis in Aspergillus nidulans. Genetics 58, 193209.CrossRefGoogle ScholarPubMed
Nga, B. H. & Roper, J. A. (1969). A system generating spontaneous intrachromosomal changes at mitosis in Aspergillus nidulans. Genetical Research 14, 6370.CrossRefGoogle ScholarPubMed
Pollard, D. R., Käfer, E. & Johnston, M. T. (1968). Influence of chromosomal aberrations on meiotic and mitotic non-disjunction in Aspergillus nidulans. Genetics 60, 743757.CrossRefGoogle Scholar
Pontecorvo, G., Roper, J. A., Hemmons, L. M., MacDonald, K. D. & Button, A. W. J. (1953). The genetics or Aspergillus nidulans. Advances in Genetics 5, 141238.CrossRefGoogle ScholarPubMed
Roper, J. A. (1952). Production of heterozygous diploids in filamentous fungi. Experientia 8, 1415.CrossRefGoogle ScholarPubMed
Roper, J. A. & Nga, B. H. (1969). Mitotic non-conformity in Aspergillus nidulans: the production of hypodiploid and hypohaploid nuclei. Genetical Resarch 14, 127136.CrossRefGoogle ScholarPubMed
Roper, J. A., Palmer, H. M. & Watmough, W. A. (1972). Mitotic nonconformity in Aspergillus nidulans: the effects of caffeine. Molecular and General Genetics 118, 125133.CrossRefGoogle ScholarPubMed