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MOLECULAR ANALYSIS OF MUTATIONS INDUCED AT THE HISD3052 ALLELE OF SALMONELLA BY SINGLE CHEMICALS AND COMPLEX MIXTURES
Citation:
DeMarini, D.M., D. Bell, J. Levine, M. Shelton, AND A. Abu-Shakra. MOLECULAR ANALYSIS OF MUTATIONS INDUCED AT THE HISD3052 ALLELE OF SALMONELLA BY SINGLE CHEMICALS AND COMPLEX MIXTURES. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-94/218 (NTIS PB94163961).
Description:
More single chemicals and complex environmental mixtures have been evaluated for mutagenicity at the hisD3052 allele of Salmonella, primarily in strain TA98, than in any other mutation assay. he development of colony probe hybridization procedures and the application of the polymerse chain reaction and direct DNA sequencing has permitted rapid molecular access to this allele. e discuss these techniques and the resulting mutation spectra that have been induced by a variety of environmental mutagens and complex mixtures. ommon GC or CG deletion within a hotspot region of the sequence dominates most of the spectra. n addition to this 2-base deletion, we have recovered approximately 200 other types of mutations within the 72-base target for reversion of the hisD3052 allele. hese include a variety of deletions (as large as 35 bases), duplications (as large as 46 bases), and complex mutations involving base substitutions. he quasipalindromic nature of the target sequence, and its potential to form DNA secondary structures and slippage mismatches, appears to be an important basis for the mutability of this allele.