Figure 1: Schematic representation of the different transgenes used to generate the PTHrP-overexperssing mice. Construct A, containing sequences for the -glutamyl transpeptidase-I (GGT-I) promoter, cDNA sequences for the Tet transactivator protein (tTA), and the SV-40 T antigen UTR, was used to generate GGT-tTA transgenic mice, resulting in specific expression of the tTA protein in the renal proximal tubule cells. Construct B, containing sequences for a hybrid regulatory element composed of a heptamerized tetracycline operator (TetoX7) fused to a minimal human cytomegalovirus promoter element, the human growth hormone (hGH) UTR, and hPTHrP (1–141) cDNA sequences, was used to generate Teto-PTHrP transgenic mice. Hemizygote mice bearing the construct A were bred with construct B-bearing hemizygote mice to induce PTHrP overexpression in renal proximal tubule cells.