Dark Recovery Phenomena in Yeast: I. Comparative Effects with Various Inactivating Agents

Cellular Radiation Effects and Hyperthermia Influence of Post-exposure Incubation Conditions

“…A similar conclusion was reached by Gillies and Alper (1959) using a different experimental approach . The temperature dependence of delayed plating recovery reported here agrees with the results of Patrick and Haynes (1964) . Delayed plating recovery in yeast may be compared to recovery from potentially-lethal damage in mammalian cells, which can be demonstrated with plateau-phase cultures (Belli and Shelton 1969) .…”

“…In a previous paper we reported on the influence of temperature variation during exposure (Kiefer, Kraft-Weyrather and Hlawica 1976) ; here we present the results of experiments in which the temperature after exposure was varied . To evaluate the possible significance of recovery phenomena, irradiated cells were also incubated under non-nutrient conditions, where survival after X-irradiation is higher owing to`liquid holding recovery ' (Patrick, Haynes and Uretz 1964) .…”

Supplement to Biology and Medicine Semiannual Report, Spring 1964

“…7 • 24 [No such interactions have been observed in the nonreactivating mutants of E. coli, nor do the uv-x or HN2-x interations occur in haploid yeast, which is unique in its inability to recover after x-irradiation; on the other hand, haploid yeast is capable o~ some recovery after uv or HN2 treatment, and correspondingly there exists an HN2-uv interaction. 24,86] The main features of the uv-x-ray interaction in E. coli B/r are shown in Figs~ 12 through 14: First, graded, preliminary uv exposure increases the x-ray sensitivity up to a factor of 3 over that of control cells which have not been exposed to uv (Fig. 12); the x-ray sensitivity of E. coli Bs-1 is similarly three times greater than that of B/r (Fig.…”

“…In.the yeast Saccharomyces cerevisiae (diploid, SC-6), a great enhancement of viability is observed if nonnutritive suspensions treated with either uv, X rays, or HN2 are stored at 30 ° c in the dark for 6 or more hours prior to plating. 86 Maximum recovery is usually observed after 24 to 48 hours' storage, and the survival curves obtained upon delayed plating are related to those for immediate plating by a constant dosemodifying factor (Figs. 3, 4, and 5); in general, the recovery DMF is greatest for x rays (2.0), intermediate for uv (1.7), and least for HN2 (1.3).…”

Dose-rate dependence of mutagenesis by ultraviolet radiation and 4-nitroquinoline 1-oxide in Escherichia coli.

“…When UV-irradiated wild-type strains of Escherichia coli and Saccharomyces cerevisiae were held in non-nutrient liquid medium before plating on nutrient medium, they showed considerably higher survivals than those plated without the "liquid-holding" procedure (Roberts and Aldous 1948;Jagger et al 1964 ;Patrick et al 1964 ;Harm 1968b;Ferguson and Cox 1980). The component of UV-induced lethal damage susceptible to the "liquid holding recovery" is common to photoreactivable DNA lesions (Setlow and Carrier 1963;Castellani et al 1964 ;Harm 1968a).…”