Characterization of new transgenic Big Blue® mouse and rat primary fibroblast cell strains for use in molecular toxicology studies†

We have established and characterized primary mouse and rat cell strains for studies designed to complement in vivo gene mutation assays using the Big Blue® mouse or rat. Primary fibroblast cell strains, designated BBM1 and BBR1, were derived from a transgenic male Big Blue® B6C3F1 mouse and from a male Big Blue® Fischer-344 rat, respectively. Both BBM1 and BBR1 are genetically stable and mostly diploid. Both cell strains have low spontaneous frequencies of mutation at the lacI and cII loci as well as low frequencies of sister chromatid exchange and micronuclei formation. In addition, N-ethyl-N-nitrosourea (ENU) induces mutations at the cII locus in both BBM1 and BBR1 cells. These new primary Big Blue® mouse (BBM1) and rat (BBR1) fibroblast cell strains represent useful new models for molecular toxicology studies. Environ. Mol. Mutagen. 34:90–96, 1999 Published 1999 Wiley-Liss, Inc.