Luciferase expression patterns in tissues isolated from different transgenic mouse lines. Mineralized tissues (calvaria, mandible, tibia) were excised from 1-, 7-, 14-, 42-, and 70-day-old mBSP9.0luc/Runx2+/− and mBSP4.8luc/Runx2+/− transgenic mice as well as their corresponding control mice. Luciferase assays were performed using a luminometer (Lumat LB9501, EG&G Berthold, Bad Wildbach, Germany). Data is presented as mean ± SE. (A) The calvaria derived from 1-d- and 7-d-old mBSP9.0luc/Runx2+/− mice showed higher luciferase expression level than those from mBSP9.0luc/Runx2+/+ mice. However, luciferase expression in 14-d-old mBSP9.0luc/Runx2+/− mice was lower than that in control mice. There was no apparent difference in luciferase expression levels between 42-d- and 70-d-old mBSP9.0luc/Runx2+/− mice and mBSP9.0luc/Runx2+/+ mice. (B) The mandibules derived from 1-d- and 7-d-old mBSP9.0luc/Runx2+/− mice showed higher luciferase expression level than those from mBSP9.0luc/Runx2+/+ mice. However, luciferase expression in mandibles isolated from older mBSP9.0luc/Runx2+/− mice (14-d-, 42-d-, and 70-d-old) was dramatically decreased compared with those at earlier stages and was lower than that in control mice. (C) The tibiae isolated from 1-d-old mBSP9.0luc/Runx2+/− mice showed higher luciferase expression level than those from mBSP9.0luc/Runx2+/+ mice. However, in 7-d- and 14-d-old animals luciferase expression was observed to be lower in tibiae from mBSP9.0luc/Runx2+/− mice than those from mBSP9.0luc/Runx2+/+ mice. In tibiae from 42-d- and 70-d-old animals, no statistically significant difference was observed between those two mouse lines. (A, B, C) Luciferase level in bone tissues of 1-d-old mBSP4.8luc/Runx2+/− mice was lower than that in the mBSP4.8luc/Runx2+/+ mice while in older mice the difference between these two mouse lines was not apparent or of no statistical significance.