ARS | Publication request: DNA DAMAGE-INDUCIBLE GENE EXPRESSION AND FORMATION OF 5-FLUOROURACIL-RESISTANT MUTANTS IN ESCHERICHIA COLI EXPOSED TO 2-DODECYCLOBUTANONE

Submitted to: Journal of Food Science
Publication Type: Research Notes
Publication Acceptance Date: November 17, 2004
Publication Date: April 28, 2005
Citation: Sommers, C.H., Mackay, W. 2005. DNA damage-inducible gene expression and formation of 5-fluorouracil-resistant mutants in escherichia coli exposed to 2-dodecyclobutanone. Journal of Food Science. 7(4):254-257.

Technical Abstract: 2-Dodecylcyclobutanone (2-dDCB) is formed by the radiolysis of palmitic acid, and is present at low part-per million (approximately 0.1 ug/g) levels in irradiated meat products. Recently, equivocal results obtained using a DNA strand breakage test, the Comet Assay, raised the possibility that 2-dDCB could be a weak genotoxin. In order to more accurately assess 2-dDCB's potential genotoxicity it was tested for the ability to increase expression of the DNA damage inducible genes dinD, nfo, recA, and umuDC using Escherichia coli that contained promoter-Beta-galacotisidase reporter constructs, and for the ability to increase the formation of 5-fluorouracil (5-FU) resistant mutants. When E. coli was exposed to 125, 250, 500, and 1000 ug/ml 2-DCB, with and without exogenous metabolic activation, no increase in dinD, nfo, recA, or umuDC gene expression, as measured by increased beta-galactosidase activity, was observed. In addition, 2-dDCB did not increase the formation of 5-FU resistant mutants in E. coli, with and without exogenous metabolic activation, at the same concentrations. No evidence of 2-dDCB-associated genotoxic activity was detected in this study.