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Growth rate and haploidization of Aspergillus niger on medium containing p-fluorophenylalanine*

Published online by Cambridge University Press:  14 April 2009

Pol Lhoas
Pol Lhoas
Affiliation:
Département de Botanique, Facultés Universitaires N.-D. de la Paix, Namur, Belgium

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1. The comparison of the dry weight of thin layer haploid and diploid colonies of A. niger on complete medium and complete medium supplemented with p-fluoro-phenylalanine led to the conclusion that there is a difference in growth rates of hyphae under these different conditions.

2. The growth curves of the same strains on both media were established. On complete medium, haploids and diploid show a growth rate increasing linearly for about 20 h after germination and reaching a maximum which is then maintained. On p-fluorophenylalanine, the haploids show a similar curve, although the maximum growth rate reached and maintained is about half that on complete medium; for the diploid, however, the maximum is less than the corresponding one in the haploid and, once this maximum has been reached, the growth rate goes down linearly to a very low value which is then maintained.

3. The cytological study of the hyphal tip cell showed, in the presence of the amino acid analogue, a reduction of the mean size of the diploid nuclei together with an increase of the number of nuclear fragments. This explains the growth rates observed and is accepted as a confirmation that p-fluorophenylalanine, by its action on the mitosis, favours chromosome losses which lead finally to the production of haploid nuclei.

Type
Research Article
Information
Genetics Research , Volume 12 , Issue 3 , December 1968 , pp. 305 - 315
Copyright
Copyright © Cambridge University Press 1968

References

REFERENCES

Clutterbuck, A. J. & Roper, J. A. (1966). A direct determination of nuclear distribution in heterokaryons of Aspergillus nidulans. Genet. Res. 7, 185–194.CrossRefGoogle Scholar
Day, A. W. & Jones, J. K. (1966). Induced haploidization in diploid cultures of Ustilago violacea. Microb. Genet. Butt. no. 25, pp. 5–6.Google Scholar
Day, A. W. & Jones, J. K. (1968). The production and characteristics of diploids in Ustilago violacea. Genet. Res. 11, 63–81.CrossRefGoogle Scholar
Käfer, E. (1961). The process of spontaneous recombination in vegetative nuclei of Asper-gillus nidulans. Genetics, Princeton 46, 1581–1609.Google Scholar
Lhoas, P. (1961). Mitotic haploidization by treatment of Aspergillus niger diploids with p-fluoro-phenylalanine. Nature, Lond. 190, 744.CrossRefGoogle Scholar
Lhoas, P. (1967). Genetic analysis by means of the parasexual cycle in Aspergillus niger. Genet. Res. 10, 45–61.CrossRefGoogle ScholarPubMed
McCully, K. S. & Forbes, E. (1965). The use of p-fluorophenylalanine with ‘master strains’ of Aspergillus nidulans for assigning genes to linkage groups. Genet. Res. 6, 352–359.CrossRefGoogle ScholarPubMed
Pontecorvo, G., Roper, J. A., Hemmons, L. M., Macdonald, K. D. & Bufton, A. W. J. (1953). The genetics of Aspergillus nidulans. Adv. Genet. 5, 141–238.Google Scholar
Roper, J. A. (1952). Production of heterozygous diploids in filamentous fungi. Experientia 8, 14–15.Google Scholar
Smith, J. H. (1924). On the early growth rate of the individual fungus hyphae. New Phytologist 23, 65–79.Google Scholar
Snedecor, G. W. (1934). Analysis of Variance and Covariance. Ames: Collegiate Press.Google Scholar