Additional lines were generated and showed comparable tissue expression patterns.

When transgenic mice were mated to mice transgenic for either lacZ or luciferase reporter genes coupled to tetracycline-responsive promoter elements (TRE), nearly uniform expression of the reporter was found in seminal vesicle, salivary gland, and Leydig cells of the double transgenic offspring. More heterogeneous patterns of reporter expression were observed in mammary epithelial cells and basal cells of the epidermis. Lower levels of reporter gene expression were also observed in a broad range of tissues. Transcriptional activation mediated by tTA was up to several hundredfold and was abrogated after the administration of tetracycline.

In combination with Tg(BCR/ABL1)2Dgt, when tetracycline administration is stopped, bitransgenic mice are models for B cell acute lymphoblastic leukemia (ALL). (J:72377)