Coinjection strategy for visual identification of transgenic mice

Abstract
Transgenic mice were generated by coinjection of a dominant marker gene that induces fur and eye pigmentation (a tyrosinase minigene) plus an unrelated DNA construction that has a γ-glutamyl transferase (γGT) promoter linked to aras oncogene. Mice transgenic for γGT-ras could be identified in the first and all subsequent generations by simple visual inspection for pigmentation. Furthermore, the γ-glutamyl transferase promoter was active in kidney but not skin of the transgenic mice, indicating that the cointegrated DNA was active and independently expressed. These results confirm that the tyrosinase minigene can be used for coinjections to allow rapid visual identification of transgenic mice.