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http://dx.doi.org/10.1016/0027-5107(80)90103-7 | DOI Listing |
The light-induced action of 8-methoxypsoralen (8-MOP) on λ phage and plasmids yields monoadducts and interstrand crosslinks. The survival and clear plaque mutation frequency in the phage photosensitized with 8-MOP and irradiated with UV at wavelength > 320 nm are increased whenthe wild-type host (Escherichia coli uvr+) is subjected to UV irradiation (wavelength = 254 nm) prior to phage inoculation. These phenomena are known as "W reactivation" and "W mutagenesis.
View Article and Find Full Text PDFGenetika
December 1989
Institute of Chemical Physics, Academy of Sciences of the USSR, Moscow.
Radiation and the majority of chemical mutagens produce lesions in the DNA of cells which provoke the induction--as a reverse response--of some inducible repair processes. One of them is the adaptive response--highly specific in the repair of damages, induced by alkylating agents. This repair pathway decreases the toxic and mutagenic effects of many alkylating agents and can be induced in Escherichia coli cells exposed to sublethal concentrations of the same agents.
View Article and Find Full Text PDFThe plating efficiency of ultraviolet-light-irradiated phage lambda in the dark is increased when an Escherichia coli recA host, which is transformed with a multicopy plasmid, pKY1, carrying the phr gene of E. coli, is irradiated with 254 nm UV prior to infection (Weigle (W) reactivation). Such W reactivation in lexA3 and umuC strains, with or without pKY1, is almost undetectable.
View Article and Find Full Text PDFAdv Space Res
April 2000
The Institute of Physical and Chemical Research, Wako-shi, Japan.
W-reactivation (WR) and W-mutagenesis (WM) were observed after irradiation of phage chi X 174 with He and N ions (4.6 MeV/amu). The relative amount of phage RFI DNA (RARFI) extracted from the infected cells was determined by agarose gel electrophoresis.
View Article and Find Full Text PDFJ Gen Microbiol
March 1982
When Escherichia coli carrying a thermosensitive mutation in DNA ligase was grown at the restrictive temperature, several functions associated with the SOS system were induced. These included lambda prophage induction, W-reactivation and W-mutagenesis of ultraviolet-irradiated lambda phage, and recA protein synthesis, all of which were lexA+ recA+ recB+ dependent and chloramphenicol sensitive, and lexA+-dependent filamentation. These results indicate that ligase-deficient growth leads to the induction of the SOS system, and that all the above functions may respond to common induction signals.
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