title: In vivo cII, gpt, and Spi⁻ gene mutation assays in transgenic mice and rats.
abstract: Transgenic mutation assays are used to identify and characterize genotoxic hazards and for determining the mode of action for carcinogens. The three most popular transgenic mutational models are Big Blue® (rats or mice), Muta™ mouse (mice), and gpt-delta (rats or mice). The Big Blue® and Muta™ mouse models use the cII gene as a reporter of mutation whereas gpt-delta rodents use the gpt gene and the red/gam genes (Spi⁻ selection) as mutation reporter genes. Here we describe methodology for conducting mutation assays with these transgenes. Transgenes recovered from tissue DNA are packaged into infectious lambda phage, bacteria are infected with the phage, and cII-mutant and Spi⁻ plaques and gpt-mutant colonies are isolated using selective conditions and quantified. Selected mutants can be further analyzed for identification of small sequence alterations in the cII and gpt genes and large deletions at the Spi⁻ locus.
authors.affiliation: Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, USA.
authors.forename: Mugimane G
authors.initials: MG
authors.lastname: Manjanatha
authors.forename: Xuefei
authors.initials: X
authors.lastname: Cao
authors.forename: Sharon D
authors.initials: SD
authors.lastname: Shelton
authors.forename: Roberta A
authors.initials: RA
authors.lastname: Mittelstaedt
authors.forename: Robert H
authors.initials: RH
authors.lastname: Heflich
mesh_terms: D000818:Animals; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004252:DNA Mutational Analysis; D042003:DNA Packaging; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics*; D056426:Genetic Loci / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins; D051379:Mice; D008822:Mice, Transgenic; D009152:Mutagenicity Tests / Q000379:methods*; D009154:Mutation; D010430:Pentosyltransferases / Q000235:genetics*; D010455:Peptides / Q000235:genetics*; D010641:Phenotype; D051381:Rats; D055647:Rats, Transgenic; D020858:Tissue and Organ Harvesting; D014157:Transcription Factors / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D029968:Escherichia coli Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D014157:Transcription Factors; D014764:Viral Proteins; C039000:cII protein, bacteriophage lambda; C086597:lambda Spi-1; D004247:DNA; D010430:Pentosyltransferases; C071962:Gpt protein, E coli