Heat-shock induction of ionizing radiation resistance in Saccharomyces cerevisiae. Transient changes in growth cycle distribution and recombinational ability. [/sup 60/Co]

Journal Article · Fri Oct 01 04:00:00 EDT 1982 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575853· OSTI ID:6325702

Mitchel, R E.J.; Morrison, D P

It was shown previously that a heat shock induces a transient increase in the resistance of wild-type Saccharomyces cerevisiae to the lethal effects of ionizing radiation. This increase was similar to the increase in resistance to thermal killing induced by the same heat shock, but appeared at a slightly earlier time after the temperature increase. This type showed that while excision-defective mutants respond like the wild type, recombination-deficient mutants do not display this heat-shock induction of radiation resistance, but still show induction of thermal resistance. Radiation survival curves of wild-type cells exposed to the elevated temperature were able to resolve two populations of cells on the basis of their sensitivity to ionizing radiation. Following a heat shock, the proportion of resitant cells increased temporarily in parallel with the increase in radiation resistance. We conclude that heat-shock induction of radiation resistance in wild-type diploid yeast results from at least two changes, an increase in recombinational repair capacity, possibly associated with G1 cells, and a shift in population distribution to a higher fraction of resistant cells. We further conclude that heat-shock induction of thermal resistance proceeds by an independent mechanism.

• Research Organization: Chalk River Laboratories, Ontario, Canada
• OSTI ID: 6325702
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 92:1; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560131* -- Radiation Effects on Microorganisms-- Basic Studies-- (-1987)
560202 -- Thermal Effects-- Microorganisms-- (1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY TEMPERATURE
CELL CYCLE
CELL KILLING
COBALT 60
COBALT ISOTOPES
ELECTROMAGNETIC RADIATION
FUNGI
GAMMA RADIATION
HYPERTHERMIA
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MICROORGANISMS
MINUTES LIVING RADIOISOTOPES
MUTANTS
NUCLEI
ODD-ODD NUCLEI
PLANTS
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RADIOISOTOPES
RADIOSENSITIVITY EFFECTS
SACCHAROMYCES
SACCHAROMYCES CEREVISIAE
SURVIVAL CURVES
YEARS LIVING RADIOISOTOPES
YEASTS