Abstract
When log phase cells of wild-type E.coli K-12 were maintained in growth medium after X-irradiation, they became progressively more resistant to a subsequent exposure to UV or X-radiation. The time to achieve maximum resistance was about 60 min. The uvrB, uvrD, polA and certain exrA strains (W3110 background) also demonstrated this X-ray-induced resistance to subsequent UV or X-irradiation but recA, recB, lex (AB1157 or W3110 backgrounds) and other exrA strains (AB1157 background) did not. The resistance induced in wild-type, uvrB and uvrD cells was characterized by the production or enhancement of a shoulder on the survival curves obtained for the second irradiation, while the resistance induced in the W3110 exrA strains was expressed only as a change in slope. The induction of resistance in the W3110 exrA strain was not inhibited by the presence of chloramphenical, but that in the wild-type cells appeared to be. The production or enhancement of a shoulder on the survival curves of the rec/sup +/ lex/sup +/ exr/sup +/ cells is consistent with the concept of the radiation induction of repair enzymes. Alternative explanations, however, are discussed.
Citation Formats
Smith, K C, and Martignoni, K D.
Protection of Escherichia coli cells against the lethal effects of ultraviolet and X-irradiation by prior X-irradiation. A genetic and physiological study.
United Kingdom: N. p.,
1976.
Web.
Smith, K C, & Martignoni, K D.
Protection of Escherichia coli cells against the lethal effects of ultraviolet and X-irradiation by prior X-irradiation. A genetic and physiological study.
United Kingdom.
Smith, K C, and Martignoni, K D.
1976.
"Protection of Escherichia coli cells against the lethal effects of ultraviolet and X-irradiation by prior X-irradiation. A genetic and physiological study."
United Kingdom.
@misc{etde_7122321,
title = {Protection of Escherichia coli cells against the lethal effects of ultraviolet and X-irradiation by prior X-irradiation. A genetic and physiological study}
author = {Smith, K C, and Martignoni, K D}
abstractNote = {When log phase cells of wild-type E.coli K-12 were maintained in growth medium after X-irradiation, they became progressively more resistant to a subsequent exposure to UV or X-radiation. The time to achieve maximum resistance was about 60 min. The uvrB, uvrD, polA and certain exrA strains (W3110 background) also demonstrated this X-ray-induced resistance to subsequent UV or X-irradiation but recA, recB, lex (AB1157 or W3110 backgrounds) and other exrA strains (AB1157 background) did not. The resistance induced in wild-type, uvrB and uvrD cells was characterized by the production or enhancement of a shoulder on the survival curves obtained for the second irradiation, while the resistance induced in the W3110 exrA strains was expressed only as a change in slope. The induction of resistance in the W3110 exrA strain was not inhibited by the presence of chloramphenical, but that in the wild-type cells appeared to be. The production or enhancement of a shoulder on the survival curves of the rec/sup +/ lex/sup +/ exr/sup +/ cells is consistent with the concept of the radiation induction of repair enzymes. Alternative explanations, however, are discussed.}
journal = []
volume = {24:6}
journal type = {AC}
place = {United Kingdom}
year = {1976}
month = {Dec}
}
title = {Protection of Escherichia coli cells against the lethal effects of ultraviolet and X-irradiation by prior X-irradiation. A genetic and physiological study}
author = {Smith, K C, and Martignoni, K D}
abstractNote = {When log phase cells of wild-type E.coli K-12 were maintained in growth medium after X-irradiation, they became progressively more resistant to a subsequent exposure to UV or X-radiation. The time to achieve maximum resistance was about 60 min. The uvrB, uvrD, polA and certain exrA strains (W3110 background) also demonstrated this X-ray-induced resistance to subsequent UV or X-irradiation but recA, recB, lex (AB1157 or W3110 backgrounds) and other exrA strains (AB1157 background) did not. The resistance induced in wild-type, uvrB and uvrD cells was characterized by the production or enhancement of a shoulder on the survival curves obtained for the second irradiation, while the resistance induced in the W3110 exrA strains was expressed only as a change in slope. The induction of resistance in the W3110 exrA strain was not inhibited by the presence of chloramphenical, but that in the wild-type cells appeared to be. The production or enhancement of a shoulder on the survival curves of the rec/sup +/ lex/sup +/ exr/sup +/ cells is consistent with the concept of the radiation induction of repair enzymes. Alternative explanations, however, are discussed.}
journal = []
volume = {24:6}
journal type = {AC}
place = {United Kingdom}
year = {1976}
month = {Dec}
}