1887

Abstract

Two spontaneous allelic mutations have been isolated with the unusual semi-dominant phenotype of faster-than-wild-type growth on acetate as sole carbon source. The mutants were designated (accelerated acetate growth) and mapped on linkage group II. Upon re-isolation of both the alleles from repeated back-crosses to wild-type, between 1 and 6% of the progeny were found to be (acetate non-utilizing) mutants. Ten of these were selected for heterokaryon complementation analysis with known mutants; nine proved to be new alleles of (deficient in acetyl-CoA synthetase), and one was a new acetate non-utilizing class, designated . Although the mutants clearly have no acetate-growth-related enzyme deficiencies, they did exhibit significant constitutive enzyme levels for acetyl-CoA synthetase and the glyoxylate cycle enzymes (isocitrate lyase and malate synthase) on the non-inducing carbon source, sucrose. The derepression was restricted to these enzymes, as representative enzymes from other carbon-assimilatory pathways remained repressed and subject to carbon catabolite repression. Northern blot analysis of the mRNA levels of acetyl-CoA synthetase and the glyoxylate cycle enzymes from the mutants demonstrated the derepression to occur at the level of transcription. These data suggest that the physiological explanation for the accelerated acetate growth phenotype lies in the standing levels of the acetate-assimilatory enzymes, which enable the mutants to forgo some of the normal time required for adaption to growth on acetate.

Loading

Article metrics loading...

/content/journal/micro/10.1099/13500872-141-6-1315
1995-06-01
2021-04-21
Loading full text...

Full text loading...

/deliver/fulltext/micro/141/6/mic-141-6-1315.html?itemId=/content/journal/micro/10.1099/13500872-141-6-1315&mimeType=html&fmt=ahah

References

  1. Apirion D. 1965; The two way selection of mutants and revertants in respect of acetate utilization and resistance to fluoroacetate in Aspergillus nidulans. . Genet Res 6:317–329
    [Google Scholar]
  2. Armitt S., McCullough W., Roberts C.R. 1976; Analysis of acetate non-utilizing (acu) mutants in Aspergillus nidulans. . J Gen Microbiol 92:263–282
    [Google Scholar]
  3. Barth G. 1985; Genetic regulation of isocitrate lyase in the yeast Yarrowia lipolytica. . Curr Genet 10:119–124
    [Google Scholar]
  4. Beever R.E. 1975; Regulation of 2-phosphoenolpyruvate kinase and isocitrate lyase in Neurospora crassa. . J Gen Microbiol 86:197–200
    [Google Scholar]
  5. Casselton L.A., Casselton P.J. 1974; Functional aspects of fluoroacetate resistance in Coprinus with special reference to acetyl- CoA synthetase deficiency.. Mol & Gen Genet 132:255–264
    [Google Scholar]
  6. Connerton I.F. 1990; Premeiotic disruption of the Neurospora crassa malate synthase gene by native and divergent DNAs.. Mol & Gen Genet 223:319–323
    [Google Scholar]
  7. Connerton I.F., Fincham J.R.S., Sandeman R.A., Hynes M.J. 1990; Comparison and cross-species expression of the acetyl-CoA synthetase genes of the ascomycete fungi,Aspergillus nidulans and Neurospora crassa. . Mol Microbiol 4:451–460
    [Google Scholar]
  8. Connerton I.F., McCullough W., Fincham J.R.S. 1992; An acetate-sensitive mutant of Neurospora crassa deficient in acetyl-CoA hydrolase.. J Gen Microbiol 138:1797–1800
    [Google Scholar]
  9. Dixon G.H., Kornberg H.L. 1959; Assay methods for key enzymes of the glyoxylate cycle.. Biochem J 72: 3P.
    [Google Scholar]
  10. Flavell R.B., Fincham J.R.S. 1968a; Acetate non-utilizing mutants of Neurospora crassa. 1. Mutant isolation, complementation studies and linkage relationships.. J Bacteriol 95:1056–1062
    [Google Scholar]
  11. Flavell R.B., Fincham J.R.S. 1968b; Acetate non-utilizing mutants of Neurospora crassa. 2. Biochemical deficiencies and roles of certain enzymes.. J Bacteriol 95:1063–1068
    [Google Scholar]
  12. Katz M.E., Hynes M.J. 1989; Isolation and analysis of the acetate regulatory gene facB, from Aspergillus nidulans. . Mol Cell Biol 12:5696–5701
    [Google Scholar]
  13. Kinnaird J.H., Keighen M.A., Kinsey J.A., Fincham J.R.S. 1982; Cloning of the am (glutamate dehydrogenase) gene of Neurospora crassa through the use of a synthetic DNA probe.. Gene 20:387–396
    [Google Scholar]
  14. Kornberg H.L. 1966; The role and control of the glyoxylate cycle in Escherichia coli. . Biochem J 99:1–11
    [Google Scholar]
  15. Kujau M., Weber H., Barth G. 1992; Characterization of mutants of the yeast Yarrowia lipolytica deficient in acetyl-coenzyme A synthetase.. Yeast 8:193–203
    [Google Scholar]
  16. McCullough W., Roberts C.F. 1980; The genetic control of isocitrate lyase in Aspergillus nidulans. . FEBS Lett 41:238–242
    [Google Scholar]
  17. McCullough W., Shanks A. 1993; Properties of genes involved in the control of isocitrate lyase production in Aspergillus nidulans. . J Gen Microbiol 139:509–511
    [Google Scholar]
  18. Maconochie M.K., Connerton I.F., Casselton L.A. 1992; The acu-1 gene of Coprinus cinereus is a regulatory gene required for induction of acetate utilisation enzymes.. Mol & Gen Genet 234:211–216
    [Google Scholar]
  19. Maniatis T., Fritsch E.F., Sambrook J. 1982 Molecular Cloning: a Laboratory Manual. Cold Spring Harbor, NY:: Cold Spring Harbor Laboratory.;
    [Google Scholar]
  20. Marathe S.Connerton, Fincham J.R.S. 1990; Duplication-induced mutation of a new Neurospora gene required for acetate metabolism: properties of the mutant and predicted amino acid sequences of the protein product.. Mol Cell Biol 10:2638–2644. Owen
    [Google Scholar]
  21. Perkins D.D. 1964; Multiple interchange stocks for linkage detection.. Neurospora Newsl 6:22–23
    [Google Scholar]
  22. Rao T.K., Debusk A.G. 1977; An inducible acetate transport system in Neurospora crassa conidia.. Biochim Biophys Acta 470:475–483
    [Google Scholar]
  23. Selker E.U., Cambereri E.B., Jensen B.C., Haack K.R. 1987; Rearrangement of duplicated DNA in specialized cells of Neurospora. . Cell 51:741–752
    [Google Scholar]
  24. Sokolovsky V., Kaldenhoff R., Ricci M., Russo V.E.A. 1990; Fast and reliable mini-prep RNA extraction from Neurospora crassa. . Fungal Genet Newsl 37:41–43
    [Google Scholar]
  25. Tatum E.L, Cutter V.M. 1949; Chemical induction of colonial paramorphs in Neurospora and Syncephelastrum. . Science 109:509–511
    [Google Scholar]
  26. Thomas G.H., Connerton I.F., Fincham J.R.S. 1988; Molecular cloning, identification and transcriptional analysis of genes involved in acetate utilization in Neurospora crassa. . Mol Microbiol 2:599–606
    [Google Scholar]
  27. Vogel H.J. 1956; A convenient growth medium for Neurospora (Medium N).. Microb Genet Bull 13:42–43
    [Google Scholar]
  28. Westergaard M., Mitchell H.K. 1947; A synthetic medium favouring sexual reproduction.. Am J Bot 34:573–577
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/13500872-141-6-1315
Loading
/content/journal/micro/10.1099/13500872-141-6-1315
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error