Fig. 1
Deletion of TG-interacting factor 1 (Tgif1) in osteoblasts reduces osteoblast differentiation and bone remodeling. a Homeodomain proteins listed according to their expression in mouse bone marrow stromal cells (BMSCs) during osteoblast differentiation. Expression is indicated as mean values (arbitrary units) with the respective standard deviation (s.d.) (N = 3). The first 10 genes are marked in shades of red and the remaining 10 genes are presented in shades of blue. b Staining of alkaline phosphatase (ALP) activity after in vitro differentiation of Tgif1+/+ and Tgif1−/− calvarial osteoblasts for 14 days (representative image of 3 experiments) and c relative Alp mRNA expression (N = 4). d Determination of matrix mineralization by Alizarin Red staining after 21 days of differentiation (representative image of 3 experiments) and e relative osteocalcin (Ocn) mRNA expression (N = 4). f Representative images of proximal tibiae of 8-week-old male mice with the genotypes Tgif1+/+, Tgif1+/− and Tgif1−/− after von Kossa staining and fluorescence double labeling to visualize bone formation (insets). g Histomorphometric analysis of the proximal tibiae of 8-week-old male Tgif1+/+, Tgif1+/− and Tgif1−/− mice (N = 10, 6 and 8). BV/TV bone volume/tissue volume, MS/BS mineralizing surface/bone surface, BFR/BS bone formation rate/bone surface, MAR mineral apposition rate, OS/BS osteoid surface/bone surface, Ob.S/BS osteoblast surface/bone surface, N.Ob/BS number of osteoblasts/bone surface, ES/BS eroded surface/bone surface, Oc.S/BS osteoclast surface/bone surface, N.Oc/BS number of osteoclasts/bone surface. *p<0.05, **p<0.01, ***p<0.001 vs. Tgif1+/+, #p<0.05, ##p<0.01, ###p<0.001 vs. Tgif1+/−. h Representative images of proximal tibiae of 8-week-old male mice with the genotypes Dmp1- Cre−;Tgif1fl/fl and Dmp1-CreTg;Tgif1fl/fl after von Kossa staining and fluorescence double labeling to visualize bone formation (insets). i Histomorphometric analysis of the proximal tibiae of 8-week-old male Dmp1-Cre−;Tgif1fl/fl and Dmp1-CreTg;Tgif1fl/fl mice (N = 9, 8). For abbreviations see g. **p<0.01, ***p<0.001 vs. Dmp1-Cre-;Tgif1fl/fl. Scale bars indicate 1 mm (black) and 50 μm (white) f, h. Error bars represent the s.e.m. Two-tailed Student's t-test was used to compare two groups c, e, i, and analysis of variance (ANOVA) followed by Newman–Keuls post-hoc analysis was used to compare three groups g
