Figure 1: Constructs for the generation of the transgenic mice. (a) Schematic map of the transgenes used in the study. pOC-Luc is composed of a 10-kb human osteocalcin enhancer/promoter sequence, with 60 bp of the 5′-untranslated sequence (white box), a luciferase gene (black box), an SV40 late polyadenylation signal (striped box), and an insulator sequence (gray box). (b) Enhanced expression of pOC-Luc by 1α,25(OH)2D3 treatment. MG-63 and HeLa cells transfected with pOC-Luc or pΔOC-Luc were incubated with 1 nM previtamin D3, 1α,25(OH)2D3, previtamin D2, 1α,25(OH)2D2, or vehicle, and then subjected to luciferase reporter assays. The -axis shows the relative luciferase activity, representing the firefly luciferase (FL) activity from the reporter plasmid normalized by the Renilla luciferase (RL) activity from the control vector. Statistical analysis was performed by Student's t-test; * relative to vehicle.