Fig. 3. Co-expression of Adamts3 and Col1a1 in the musculoskeletal system. All images are from 15.5 and 17.5 dpc embryos; Hoechst 33258-stained images are shown in the right-hand panel. (A) Expression in the appendicular skeleton (proximal humerus). Note that Adamts3 expression overlaps with Col1a1 in bone (B) and in the perichondrium around the hypertrophic zone and the periosteum (around bone). Chondrocytes in the proliferating zone (PZ) and hypertrophic zone (HZ) are indicated; arrows indicate mRNA in muscle. (B) Expression in the craniofacial skeleton. Note co-expression of Col1a1 and Adamts3 in bone (B) in the mandible and maxilla, as well as in developing masseter muscle (mt). (C) Expression in the proximal femur. The trochanteric fossa (TF), which contains the obturator tendons, is indicated by the arrow. The left panel in this figure is the same as that in Fig. 2D. (D) Expression in the developing Achilles tendon at 15.5 dpc. The image on the left shows Adamts3 expression in the ankle cartilage (C) and tendon (arrow); that on the right shows the Achilles tendon at a higher magnification (boxed area in middle panel). Scale bar: 100 µm.