Fig. 1. Progressively increased bone marrow fat in adult mice following postnatal knockout of β-catenin through the osterix promoter.
(A–B) H&E staining of paraffin sections from proximal tibiae of 6-month old control (β-catf/f) and knockout (osx-cre;β-catf/f) mice treated with doxycycline (Dox, 1.5 mg/ml supplemented in drinking water) prenatally and until 4 months of age (A) or until 2 months of age (B). Treatment with Dox suppresses cre expression and thus prevents disruption of β-catenin. The earlier disruption of β-catenin by osx-cre at 2 months (B), led to more marrow adipose tissue and more bone loss in the knockout mice at 6 months. (C) μCT analysis of distal femurs and (D) von Kossa staining of plastic sections of proximal tibiae from 12-wk old mice treated with Dox prenatally and until 7 weeks of age.