Fig. 1

The Fgfr3^N534K/+ mouse model of hypochondroplasia exhibits morphologic defects of the mandible. a Representative images of Meckel’s cartilage (MC) samples at E13.5 (Sirus Red/Alcian Blue staining). Scale bar: 200 µm. Sox 9 and FGFR3 immunostaining. Scale bar: 100 µm. Graphical representation of MC area and Sox9 staining. Fgfr3^+/+ (n = 6) and Fgfr3^N534K/+ mice (n = 5). b Representative images of Fgfr3^+/+ and Fgfr3^N534K/+ MC at E16.5 stained with Safranin O/Fast Green. Scale bar: 200 µm. Sox 9, collagen X and Fgfr3 immunostaining. Scale bar: 200 µm. Graphical representation of the MC area (Safranin O staining) and percentage ratio between hypertrophic area (collagen X) and total MC surface area (Safranin O). Fgfr3^+/+ (n = 7) and Fgfr3^N534K/+ (n = 7) mice. c Representative images of condylar cartilage at P21 from Fgfr3^+/+ and Fgfr3^N534K/+ mice (Safranin O/Fast Green) and collagen X immunostaining. Scale bar: 100 µm. Graphical representation of mean percentage of hypertrophic chondrocytes in different size categories (in µm²) inside the condylar cartilage of Fgfr3^+/+ (n = 5) and Fgfr3^N534K/+ mice (n = 6) (n > 50 cells for each genotype). d Representative µCT images of the skull bone at P42 from Fgfr3^+/+ and Fgfr3^N534K/+ mice (lateral orientation). Scale bar: 3 mm. Graphical representation of naso-occipital length, skull width, mandible length, mandibular ramus height (mm) from Fgfr3^+/+ (n = 7) and Fgfr3^N534K/+ mice (n = 7). e 3D representations of landmarks and associated wireframe variations in skull and mandibular shapes in P42 Fgfr3^+/+ and Fgfr3^N534K/+ mice after PC analysis. Shape comparison of skull and mandible (*: mandibular condyle; °: mandibular angle) (skull: Procrustes distance d = 0.109 4; P < 0.001; mandible: Procrustes distance d = 0.084 6; P < 0.001) in Fgfr3^+/+ vs. Fgfr3^N534K/+ mice, based on the scores for PC1 and PC2 (n = 7 mice for each genotype). *P < 0.05, **P < 0.01, ***P < 0.005