eCite Digital Repository

Catabolite repressors are potent antimutagens in Escherichia coli plate incorporation assays: experiments with glucose, glucose-6-phosphate and methyl-alpha-D-glucopyranoside

Citation

Ambrose, M and MacPhee, DG, Catabolite repressors are potent antimutagens in Escherichia coli plate incorporation assays: experiments with glucose, glucose-6-phosphate and methyl-alpha-D-glucopyranoside, Mutation Research, 398, (1-2) pp. 175-82. ISSN 0027-5107 (1998) [Refereed Article]

Copyright Statement

Copyright 1997 Elsevier Science Bv

DOI: doi:10.1016/S0027-5107(97)00315-1

Abstract

Having previously found that the yields of spontaneous valine-resistant (Val(r)) Escherichia coli mutants which appeared on plates containing 40 microg/ml of valine were always much lower when glucose was present in the glycerol-containing defined medium normally used to select them, we now sought to determine whether or not the global regulatory mechanism known as catabolite repression (formerly also called glucose repression) might be involved. We therefore tested glucose (the archetypal catabolite repressor), glycerol (a non catabolite-repressing substrate), glucose-6-phosphate (G6P, an exceptionally powerful catabolite repressor) and methyl-alpha-D-glucopyranoside (alphaMG, a strongly catabolite-repressing but non-utilisable glucose analogue), as potential inhibitors of spontaneous mutagenesis in plate incorporation assays, using three distinct mutation detection systems. We found that the numbers of spontaneous Val(r) and Lac+ mutations appearing on the selective plates tended to be highest when the medium contained only a non-repressing primary carbon source (glycerol in the Val(s) --> Val(r) system, lactose in the Lac- --> Lac+ system) and lowest when it had been supplemented with a strongly catabolite-repressing compound such as alphaMG, G6P or glucose. These results would seem to establish that catabolite repression is an important factor in determining the outcome of the spontaneous mutation generation process in E. coli and hence that the numbers of spontaneous mutations which can be expected to arise in any given set of mutation assay conditions may often be dependent upon the levels of catabolite repression which prevail during the course of the assay. The implications of these results for conventional plate-incorporation mutation assays are discussed.

Item Details

Item Type:Refereed Article
Keywords:SOS repair, Escherichia coli, catabolite repression
Research Division:Biological Sciences
Research Group:Genetics
Research Field:Anthropological Genetics
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Endocrine Organs and Diseases (excl. Diabetes)
Author:Ambrose, M (Dr Mark Ambrose)
ID Code:87163
Year Published:1998
Web of Science® Times Cited:7
Deposited By:Medicine (Discipline)
Deposited On:2013-11-08
Last Modified:2013-12-05
Downloads:0

Repository Staff Only: item control page