The transgenic mice express rearranged Valpha and Vbeta genes from a CTL clone that recognized the SV40 large T antigen (SV-T). The V and J regions of a transgene construct (made in J:107523) were replaced with the V and J regions of the clone K T cell receptor. The synthetic alpha and beta constructs were coinjected into 1 day embryos. Three lines were obtained and line TG-B was further characterized. The transgene in line TG-B inserted into intron 1. Western blot analysis confirmed reduced protein expression.