Molecular and General Genetics MGG

, Volume 181, Issue 3, pp 283–287 | Cite as

Both caffeine-induced lethality and the negative liquid holding effect, in UV- or γ-irradiated wild-type Schizosaccharomyces pombe, are consequences of interference with a recombinational repair process

  • Norman E. Gentner


UV- or γ-irradiated G2 phase cells of rad+Schizosaccharomyces pombe show increased inactivation if incubated post-irradiation, in liquid growth medium containing caffeine, before being plated on normal agar medium. The following, however, do not show such caffeine-induced lethality: G1 phase rad+ cells; ascospores of a rad+ strain; either G2 or G1 phase cells of the recombination-deficient rad1 strain; unirradiated rad+ cells. Of the above, only the G2 phase rad+ cells possess, at the time of radiation exposure, the capability for recombination. These results indicate that a recombinational process is responsible for caffeine-induced lethality after exposure to UV or ionizing radiation.

Similarly, the negative liquid holding effect (a progressive inactivation seen if UV- or γ-irradiated cells are incubated in non-nutritive medium such as buffer before being plated) is manifested only in G2 phase rad+ cells, and not in either G1 phase rad+ cells or rad1 cell (whether G2 or G1 phase). Both the negative liquid holding effect and caffeine-induced lethality therefore are seen only in cells which fulfill all of the following conditions: (a) they must be genetically recombination-proficient; (b) they must possess at the time of irradiation the necessary two DNA copies with which to perform recombinational repair (for a haploid cell, this means they must be in G2 phase); (c) their DNA must be damaged, such as by UV or γ-ray exposure, thus requiring that recombinational repair capability be exercised in order to maintain viability; and (d) they must be incubated under conditions that fail to support the normal progress of recombinational repair. The exercising of recombinational repair capability has been shown to require an incubation medium capable of supporting growth. The incubation conditions that give rise to further inactivation of irradiated cells (non-nutritive liquid holding medium in the case of the negative liquid holding effect and exposure to caffeine in the case of caffeine-induced lethality) have been demonstrated not to support recombinational repair.


Caffeine Phase Cell Recombinational Process Rad1 Strain Irradiate Cell 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Abbondandolo A (1975) Mutation and nuclear stage in Schizosaccharomyces pombeI. An experimental approach to the role of recombination in mutation induction. Mutat Res 27:225–233Google Scholar
  2. Abbondandolo A, Bonatti S (1970) The production, by nitrous acid, of complete and mosaic mutations during defined nuclear stages in cells of Schizosaccharomyces pombe. Mutat Res 9:59–69Google Scholar
  3. Abbondandolo A, Simi S (1971) Mosaicism and lethal sectoring in G1 cells of Schizosaccharomyces pombe. Mutat Res 12:143–150Google Scholar
  4. Bostock CJ (1970) DNA synthesis in the fission yeast Schizosaccharomyces pombe. Exp Cell Res 60:16–26Google Scholar
  5. Clarke CH (1968) Differential effects of caffeine in mutagen-treated Schizosaccharomyces pombe. Mutat Res 5:33–40Google Scholar
  6. Fabre F (1970) UV-sensitivity of the wild-type and different UVS mutants of Schizosaccharomyces pombe: influence of growth stages and DNA content of the cells. Mutat Res 10:415–426Google Scholar
  7. Fabre F (1971) A UV-supersensitive mutant in the yeast Schizosaccharomyces pombe: evidence for two repair pathways. Mol Gen Genet 110:134–143Google Scholar
  8. Fabre F (1972) Relation between repair mechanisms and induced mitotic recombination after UV-irradiation, in the yeast Schizosaccharomyces pombe: effects of caffeine. Mol Gen Genet 117:153–166Google Scholar
  9. Fabre F (1973) The role of repair mechanisms in the variations of ultra-violet and γ-radiation sensitivity during the cell cycle of Schizosaccharomyces pombe. Radiat Res 56:528–539Google Scholar
  10. Gentner NE (1977) Evidence for a second “prereplicative G2” repair mechanism, specific for γ-induced damage, in wild-type Schizosaccharomyces pombe. Mol Gen Genet 154:129–133Google Scholar
  11. Gentner NE, Werner MM (1975) Repair in Schizosaccharomyces pombe as measured by recovery from caffeine enhancement of radiation-induced lethality. Mol Gen Genet 142:171–183Google Scholar
  12. Gentner NE, Werner MM (1976) Effect of protein synthesis inhibition on recovery of UV- and γ-irradiated Schizosaccharomyces pombe from repair inhibition by caffeine. Mol Gen Genet 145:1–5Google Scholar
  13. Gentner NE, Werner MM (1977) Slow UV-recovery and fast γ-recovery in wild-type Schizosaccharomyces pombe. Mol Gen Genet 154:123–128Google Scholar
  14. Gentner NE, Werner MM (1978) Synergistic interaction between UV and ionizing radiation in wild-type Schizosaccharomyces pombe. Mol Gen Genet 164:31–37Google Scholar
  15. Gentner NE, Werner MM, Hannan MA, Nasim A (1978) Contribution of a caffeine-sensitive recombinational repair pathway to survival and mutagenesis in UV-irradiated Schizosaccharomyces pombe. Mol Gen Genet 167:43–49Google Scholar
  16. Guglielminetti R, Schüpbach M (1969) Mechanisms of dark repair and photoreactivation in Schizosaccharomyces pombe. Atti Assoc Genet Ital 14:182–184Google Scholar
  17. Harm W, Haefner K (1968) Decreased survival resulting from liquid holding of UV-irradiated Escherichia coli C and Schizosaccharomyces pombe. Photochem Photobiol 8:179–192Google Scholar
  18. Leupold U (1957) Physiologisch-genetische Studien an adenin-abhängigen Mutanten von Schizosaccharomyces pombe. Schweiz. A Path Bakt 20:535–544Google Scholar
  19. Loprieno N, Guglielminetti R (1969) Repair of prelethal and premutational damages in Schizosaccharomyces pombe. Antonie V Leeuwerhoek 35 (Suppl), C15-C16Google Scholar
  20. Loprieno N, Schüpbach M (1971) On the effect of caffeine on mutation and recombination in Schizosaccharomyces pombe. Mol Gen Genet 110:348–354Google Scholar
  21. Nasim A, Smith BP (1974) Dark repair inhibitors and pathways for repair of radiation damage in Schizosaccharomyces pombe. Mol Gen Genet 132:13–22Google Scholar
  22. Shahin MM, Gentner NE, Nasim A (1973) The effect of liquid holding in Schizosaccharomyces pombe strains after gamma and ultraviolet irradiation. Radiat Res 53:216–225Google Scholar
  23. Shahin MM, Nasim A (1973) The effect of radiation sensitivity and cell stage on liquid holding response in Schizosaccharomyces pombe. Mol Gen Genet 122:331–338Google Scholar

Copyright information

© Springer-Verlag 1981

Authors and Affiliations

  • Norman E. Gentner
    • 1
  1. 1.Health Sciences DivisionAtomic Energy of Canada Research Company, Chalk River Nuclear LaboratoriesChalk RiverCanada

Personalised recommendations