Figure 1.

3D Analysis of the human chondrocranium development

All panels are LSFM images of solvent-cleared embryos and fetus, immunostained with anti-Collagen 2 (A–L) or anti-Sox9 (M) antibodies.

(A–C) Lateral 3D views of a PCW7 embryo illustrating the image processing pipeline. Raw image data (A) are segmented using syGlass (B) to isolate all cartilage templates and a mesh image is built (C) for 3D rendering.

(D and E) (D) All individual skeletal elements have been colored (lateral view). (E) is a frontal view of the same embryo.

(F–M) (F) High-magnification 3D rendering of the cranium with all developing cartilage elements pseudocolored. Names appear on the chart on the right of the image. (G)–(L) are views of each element taken in situ (top panels) or isolated (bottom panels). The nasal capsule (G) assembles the mesethmoid (Mes) and ectethmoid (Ect). The hyoid and the larynx (elements numbered 1–4) are seen in (H). In (I), The Meckel’s cartilages join at the symphysis (arrowhead). (J) Frontal (upper panel) and superior (lower panel) views of the sphenoid. (K) shows the inner ear bones (dark purple, malleus; pink, incus; red, stapes) and their insertion in the petrous (yellow). In (L), the basilar process (arrowhead) and foramen magnum (asterisk) of the chondrogenic ventro-posterior component of the presumptive occipital bone complex are seen. (M) displays the developmental time course of the cranium in human from 5.6 to 11 PCW. All panels are 3D rendering images generated with syGlass from LSFM images of embryos (PCW5.6, PCW7, and PCW8) and fetus (PCW11.3) immunostained with anti-Sox9. Images are presented at the same scale to illustrate the growth of the cranium.

See also Figure S1.

Scale bars: 2 mm in (A)–(D) and (L, top panel), 4 mm in (E), 1 mm in (F)–(K), 3 mm in (L, bottom panel), and 1.5 mm in (M).