Deletion of Tbx5 by Osr2Cre Produces Muscle and Tendon Patterning Defects
Muscles and tendons labeled for myosin and ScxGFP, respectively. Dorsal view of control E13.5 (A and C), E14.5 (E, G, K, M, and O), and E16.5 (I) forelimbs and equivalent stages of mutant E13.5 (B and D), E14.5 (F, H, L, N, and P), and E16.5 (J) forelimbs. Black and white arrows indicate single ECR bundle (H) and a single tendon (B, F, and L) in mutant. Optical projection tomography (OPT) scans of control (K) and mutant (L) limbs at E14.5. Optical dissection of the ECRl, ECRb, EPl, and EPb of the sample shown in (K) (M). Equivalent optical dissection of the mutant shown in (L) showing single ECR and EP bundles (N). Dotted white lines in (M) and (N) show approximate position of optical slice through the 3D reconstruction made to generate the top images in (O) and (P), respectively. Bottom panels in (O) and (P) show rotated views of ECR to show the 2 tendons of ECRl and ECRb in the control and the single ECR tendon in the mutant (asterisks).