Changes in survival of Escherichia coli K-12 cells as a function of the medium in which they are x irradiated. A rec and exr gene-dependent phenomenon

Journal Article · Mon Oct 01 00:00:00 EDT 1973 · Int. J. Radiat. Biol., v. 24, no. 4, pp. 355-362

OSTI ID:4349209

Van der Schueren, E; Youngs, D A; Smith, K C

Escherichia coli K-l2 wild-type cells suspended in growth medium during x irradiation have a higher survival than cells irradiated in buffer, whether irradiated in air or nitrogen. To determine if this response was due to differences in radiochemistry during irradiation or to differences in the amount of repair, the influence of the irradiation medium on the survival of several repair-deficient mutants (recA, recB, exrA, uvrB, polAl, and polAl exrA) and the repair of radiationinduced DNA single-strand breaks in a wild-type strain were studied. The studies showed that the effect of the irradiation medium on survival was dependent on the presence of functional recA, recB, and exrA genes. Sedimentation studies, however, did not show a difference in the final amount of repair of DNA single-strand breaks after x irradiation in buffer or growth medium. Thus, the increased x-ray sensitivity resulting from irradiation in buffer appears to be due to the inhibition of some rec and exr gene-dependent repair process other than the repair of DNA single-strand breaks. (auth)

• Research Organization: Stanford Univ., CA
• NSA Number: NSA-29-015898
• OSTI ID: 4349209
• Journal Information: Int. J. Radiat. Biol., v. 24, no. 4, pp. 355-362, Journal Name: Int. J. Radiat. Biol., v. 24, no. 4, pp. 355-362; ISSN IJRBA
• Country of Publication: United Kingdom
• Language: English

Related Subjects

*CULTURE MEDIA-- RESPONSE MODIFYING FACTORS
*ESCHERICHIA COLI-- BIOLOGICAL RADIATION EFFECTS
ANIMAL CELLS
BIOLOGICAL REPAIR
BUFFERS
DNA
GENES
GROWTH
MUTANTS
N48310* --Life Sciences--Radiation Effects on Microorganisms- -Basic Studies
PHOTON BEAMS
RADIOSENSITIVITY
SEDIMENTATION
STRAND BREAKS
SURVIVAL CURVES
X RADIATION