Fig. 4.

Woven bone-like region in the Hox11 conditional mutant bones has a disorganized collagen matrix. Hox11 conditional mutants with the ROSA-CreER^T2 (genotype indicated) allele along with control animals were fed on tamoxifen chow for 3 wk beginning at 8 to 10 wk of age to induce deletion, and animals were examined at 6 mo of age. (A and B) H&E stains of paraffin-processed bone sections of control and Hox11^ROSACreERT2 conditional mutant animals. (C and D) Brightfield images of picrosirius red stain of consecutive bone sections from A and B. (E and F) Polarized light images of picrosirius red stain of bone sections from C and D. (G and H) H&E stains of paraffin-processed bone sections of control and Hox11^ROSACreERT2 conditional mutant animals. (I and J) Consecutive bone sections from G and H stained with ^Cy5CMP (red). White dashed line marks border of cortical bone. (K and L) Control (K) and Hox11^ROSACreERT2 conditional mutant (L) bone sections stained with TRAP. Note the distinct distribution of TRAP stain in conditional mutant. (M) Quantification of osteoclast number (N. Oc) on bone surface (BS) using the Bioquant Osteo software. Statistics by Student’s t test. Error is represented as mean ± SEM. All images are from the ulna. BM, bone marrow; CB, cortical bone; PO, periosteum. The yellow dashed line demarcates border between lamellar (above) and abnormal (below) bone. ns, not significant. (Scale bar in all images: 100 μm.)