Hostname: page-component-76fb5796d-5g6vh Total loading time: 0 Render date: 2024-04-28T05:53:24.272Z Has data issue: false hasContentIssue false

Genetical analysis of proline mutants and their suppressors in Aspergillus nidulans

Published online by Cambridge University Press:  14 April 2009

P. Weglenski
Affiliation:
Department of Genetics, Warsaw University
Rights & Permissions [Opens in a new window]

Extract

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.

1.Complementation between thirteen proline auxotrophs in A. nidulans was studied. Two groups of mutants with different complementation pattern were found. These two groups could also be distinguished on the basis of recombination tests.

2. The spontaneous reversion rate of proline mutants was established. In all cases studied the reversions were due to suppressor mutations. Dominant, semi-dominant and recessive suppressors were distinguished.

3. Complementation between recessive suppressors was studied. Only a few of the suppressors obtained could be located in different complementation groups.

4. Three suppressor loci were mapped, two of them, su-2 and su-6 in chromosome III linked to the phen-2 locus, respectively 22 and 26 map units distant, and the third in chromosome I, linked to the ad-9 locus (1·9 map units). su-2 is a mutant at the Su-4 pro locus already identified by Forbes (1956).

5. The action of these suppressors is thought to consist in affecting the pathway of arginine synthesis by one of three mechanisms: (1) accumulation of an inter mediate (ornithine); (2) increased activity of ornithine δ-transaminase; and (3) a third, as yet, unclear process possibly involving feed-back regulation of arginine synthesis or the regulation of arginine breakdown to ornithine.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1966

References

REFERENCES

Andersson-Kotto, I. & Ehrensvard, G. (1963). The integrative effect of some genetical and exogeneous factors upon amino acid formation in Neurospora crassa. Hereditas, 50, 152.CrossRefGoogle Scholar
Davis, B. D. (1955). Intermediates in amino-acid biosynthesis. Adv. Enzymol. 16, 247312.Google ScholarPubMed
Davis, R. H. (1962). Consequences of a suppressor gene effective with pyrimidine and proline mutants of Neurospora. Genetics, 47, 351360.CrossRefGoogle ScholarPubMed
Forbes, E. C. (1956). Recombination in the pro region in Aspergillus nidulans. Microb. Genet. Bull. 13, 910.Google Scholar
Garen, A. & Siddiqi, O. M. (1962). Suppression of mutations in the alkaline phosphatase structural cistron of E. coli. Proc. natn. Acad. Sci. U.S.A. 48, 11211127.CrossRefGoogle ScholarPubMed
Morgan, D. H. (1966). Regulation of arginine biosynthesis in Neurospora crassa. Heredity, Lond. in press.Google Scholar
Pontecorvo, G., Roper, J. A., Hemmons, L. M., Macdonald, R. D. & Bufton, A. W. J. (1953). The genetics of Aspergillus nidulans. Adv. in Genet. 5, 141238.CrossRefGoogle ScholarPubMed
Vogel, H. J. (1955). On the glutamate–proline–ornithine interrelations in various microorganisms. In Amino acid metabolism, ed. McElroy, W. D., Glass, B., Baltimore, 335346.Google Scholar
Vogel, H. J. & Bonner, D. M. (1954). On the glutamate–proline–ornithine interrelation in Neurospora crassa. Proc. natn. Acad. Sci. U.S.A. 40, 688694.CrossRefGoogle ScholarPubMed
Vogel, R. H. & Kopac, M. J. (1959). Glutamic γ-semialdehyde in arginine and proline synthesis in Neurospora. A mutant-tracer analysis. Biochim. biophys. Acta, 36, 505510.CrossRefGoogle Scholar
Vogel, R. H. & Vogel, H. J. (1963). Evidence for acetylated intermediates of arginine synthesis in Neurospora crassa. Genetics, 48, 914.Google Scholar