Extended Data Figure 5: Histology of MPC-D102/109 left tibia and fibula.

a, Interpretative histological drawing of tibia and fibula. b, Photomicrograph under cross-polarized light of boxed area in a. c, Cortical bone of the tibia under cross-polarized light with lambda waveplate, which reveals a LAG. d, Cortical bone of the tibia under cross-polarized light with lambda waveplate; this cross-section shows clearly the sharp cementing line boundary between the innermost remodelled and the outermost primary cortex. e, Close-up of the boxed area in d, with primary parallel-fibred bone with predominantly longitudinal canals and one LAG (white arrow) indicated. The cementing line that separates the outermost primary from the innermost remodelled cortex lies directly below the LAG. In the remodelled cortex, woven-bone osteocyte lacunae are visible in the lower left corner. No outer circumferential lamellae are visible. f, Close-up of the boxed area in d, with remodelled bone (black arrow) indicated. Several of the secondary osteons are surrounded by woven-bone osteocyte lacunae. A patch of inner circumferential lamellae is visible in the lower left corner. In panels a and d, b–f refer to their corresponding panels in the figure. Scale bars, 2 mm (a), 0.85 mm (b) and 0.35 mm (c–f).