Model systems for detecting mutations in animal cells and transgenic mice

We have initiated studies towards the development of a transgenic mouse system that permits efficient detection of mutagens. A modified lacZ gene incorporating the nuclear location signal (NLS) of SV40 large T antigen was generated to facilitate detection of ;To overcome the difficulty of expressing the bacterial lacZ gene in adult mouse tissues, we have explored the possibility of using the rat peripherin gene as the target gene. We chose the rat peripherin gene as our reporter gene because its expression is limited to a subset of neurons and because of its ability to form stable filament network. These characteristics should permit easy detection of ectopically expressed peripherin. The feasibility of this gene as a reporter gene in mutagenesis studies was explored. We first demonstrated that peripherin forms a homopolymer in cultured cells. Then we successfully expressed peripherin in adult mouse livers and demonstrated that ectopic expression of peripherin is not detrimental to the animals.;We have initiated studies towards site-directed mutagenesis of this transgene and in this process have provided insights into the mechanics of peripherin assembly using tissue culture cell lines. Transgenic mice carrying mutated peripherin genes are currently being generated and would alternatively serve as animal models for mutagen detection.