1887

Abstract

In order to carry out a systematic search for mutants affected in cell integrity, the diploid strain D1 was subjected to mutagenesis with ethyl methane sulphonate (EMS), and mutant clones were screened for thermosensitive autolytic phenotypes. The screening was based on examination of cell populations, from individual mutant clones, stained with propidium iodide to establish the proportion of cells lysing under non-permissive conditions by means of flow cytometry. Osmotic remediation of the autolytic phenotype in the presence of 1 M sorbitol was also checked. Out of 13300 clones surviving mutagenesis, 34 were confirmed to be thermosensitive autolytic and 7 of them showed some osmotic complementation with regard to growth and cell lysis. The osmotic remediation in the other strains was negligible or affected only one of the two parameters. The expression of the mutant phenotype in the strains isolated led to a sporulation defect (40% of the strains) and significant alterations in morphology, such as cells in chains (35%), altered buds (25%) that eventually might elongate, round unbudded and highly vacuolated cells (12%) and largesized cells (12%). These observations show that alterations in functions related to cell integrity can be correlated with an altered morphology. Genetic analysis of the mutant strains that could sporulate showed that in many instances the mutant phenotype was the result of more than one mutation, the mutations being individually recessive. However, at least one mutant strain, 933, carried a single mendelian mutation that was dominant in the diploid but haploid segregants were non-viable. Dominance of this mutation was also confirmed in tetraploids obtained by means of protoplast fusion.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-140-3-559
1994-03-01
2022-01-21
Loading full text...

Full text loading...

/deliver/fulltext/micro/140/3/mic-140-3-559.html?itemId=/content/journal/micro/10.1099/00221287-140-3-559&mimeType=html&fmt=ahah

References

  1. Bender A., Pringle J.R. Use of a screen for synthetic lethal and multicopy suppressor mutants to identify two new genes involved in morphogenesis in Saccharotnyces cerevisiae. Mol Cell Biol 1991; 11:1295–1305
    [Google Scholar]
  2. Borgia P.B., Dodge C.L. Characterization of Aspergillus nidulans mutants deficient in cell wall chitin or glucan. J. Bacteriol 1992; 174:377–383
    [Google Scholar]
  3. Brewster J.L., De Valoir T., Dwyer N.D., Winter E., Gustin M.C. An osmosensing signal transduction pathway in yeast. Science 1993; 259:1760–1763
    [Google Scholar]
  4. Cabib E., Duran A. Simple and sensitive procedure for screening yeast mutants that lyse at non-permissive temperatures. J Bacteriol 1975; 124:1604–1606
    [Google Scholar]
  5. Costigan C., f Gehrung S., Snyder M. A synthetic lethal screen identifies SLK1, a novel protein kinase homolog implicated in yeast cell morphogenesis and cell growth. Mol Cell Biol 1992; 12:1162–1178
    [Google Scholar]
  6. De La Fuente J.M., Vazquez A., Nombela C., Sanchez M. Flow cytometric analysis of Saccharotnyces cerevisiae autolytic mutants and spheroplasts. Yeast 1992; 8:39–45
    [Google Scholar]
  7. De La Fuente J.M., Vazquez A., Gonzalez M.M., Sanchez M., Molina M., Nombela C. Expression of mutations and protein release by yeast conditional autolytic mutants in batch and continuous cultures. Appl Microbiol Biotechnol 1993; 38:763–769
    [Google Scholar]
  8. Ford S.K., Pringle J.R. Cellular morphogenesis in the Saccharotnyces cerevisiae cell cycle: localization of the CDC11 gene product and the timing of events at the budding site. Dev Genet 1991; 12:281–292
    [Google Scholar]
  9. Kakar S.N., Magee P.T. Genetic analysis of Candida albicans-, identification of different isoleucine-valine, methionine and arginine alleles by complementation. J Bacteriol 1982; 151:1247–1252
    [Google Scholar]
  10. Kim H.B., Haarer B.K., Pringle J.R. Cellular morphogenesis in the Saccharotnyces cerevisiae cell cycle: localization of the CDC3 gene product and the timing of events at the budding site. J Cell Biol 1991; 112:535–544
    [Google Scholar]
  11. Kuranda M.J., Robbins P.W. Chitinase is required for cell separation during growth of Saccharotnyces cerevisiae. J Biol Chem 1991; 266:19758–19767
    [Google Scholar]
  12. Lee K.S., Levin D.E. Dominant mutations in a gene encoding a putative protein kinase (BCK1) bypass the requirement for a Saccharomyces cerevisiae protein kinase C homolog. Mol Cell Biol 1992; 12:172–182
    [Google Scholar]
  13. Lee K.S., Irie K., Gotoh Y., Watanabe Y., Araki H., Nishida E., Matsumoto K., Levin D.E. A yeast MAP kinase homolog (PK1) mediates signaling by protein kinase C. Mol Cell Biol 1993; 13:3067–3075
    [Google Scholar]
  14. Levin D.E., Fields F.O., Kunisawa R., Bishop J.M., Thorner J. A candidate protein kinase gene, PKC1, is required for the Saccharomyces cerevisiae cell cycle. Cell 1990; 62:213–224
    [Google Scholar]
  15. Madden K., Costigan C., Snyder M. Cell polarity and morphogenesis in Saccharomyces cerevisiae. Trends Cell Biol 1992; 2:22–29
    [Google Scholar]
  16. Martin H., Arroyo J., Sanchez M., Molina M., Nombela C. Activity of the yeast MAP kinase homologue Slt2 is critically required for cell integrity at 37 °C. Mol & Gen Genet 1993; 241:177–184
    [Google Scholar]
  17. Nombela C., Molero G., Martin H., Cenamor R., Molina M., Sanchez M. Genetic control of fungal cell wall autolysis. In Bacterial Growth and Lysis: Metabolism and Structure of the Murein Sacculusipip 1993 Edited by De Pedro M.A., Holtje J.V., Loffelhardt W. London: Plenum Press; pp 285–294
    [Google Scholar]
  18. Paravicini G., Cooper M., Friedli L., Smith D.J., Carpenter J.L., Klig L.S., Payton M. The osmotic integrity of the yeast cell requires a functional PKC1 gene product. Mol Cell Biol 1992; 12:4896–4905
    [Google Scholar]
  19. Payton M., De Tiani M. The isolation of osmotic- remedial conditional lethal mutants of Candida albicans. Curr Genet 1990; 17:293–296
    [Google Scholar]
  20. Ribas J.C., Diaz M., Duran A., Perez P. Isolation and characterization of Schizosaccharomyces pombe mutants defective in cell wall (1-3)β-D-glucan. J Bacteriol 1991; 173:3456–3462
    [Google Scholar]
  21. Roncero C., Valdivieso M.H., Ribas J.C., Duran A. Effect of calcofluor white on chitin synthases from Saccharomyces cerevisiae. J Bacteriol 1988; 170:1945–1949
    [Google Scholar]
  22. Ronne H., Carlberg M., Hu G.Z., Nehlin J.O. Protein phosphatase 2A in Saccharomyces cerevisiae : effects on cell growth and bud morphogenesis. Mol Cell Biol 1991; 11:4876–4884
    [Google Scholar]
  23. Torres L., Martin H., Garcia-Saez M.I., Arroyo J., Molina M., Sanchez M., Nombela C. A protein kinase gene complements the lytic phenotype of Saccharomyces cerevisiae lyt2 mutants. Mol Microbiol 1991; 5:2845–2854
    [Google Scholar]
  24. Stateva L.I., Oliver S.G., Trueman L.J., Venkov P.V. Cloning and characterization of a gene which determines osmotic stability in Saccharomyces cerevisiae. Mol Cell Biol 1991; 11:4235–4243
    [Google Scholar]
  25. Venkov P.V., Hadjiolov E., Battaner E., Schlessinger D. Saccharomyces cerevisiae sorbitol dependent fragile mutants. Biochem Biophys Res Commun 1974; 56:559–604
    [Google Scholar]
  26. Williams S.T., Veldkamp C.I. Preparation of fungi for scanning electron microscopy. Trans Br Mycol Soc 1974; 63:409–412
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-140-3-559
Loading
/content/journal/micro/10.1099/00221287-140-3-559
Loading

Data & Media loading...

Most cited this month Most Cited RSS feed

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