Figure 4. Radiographs of FGFR3^ACH/+ (ACH/ + ), FGFR3ACH/ACH (ACH/ACH), and WT mice (WT).

FGFR3^ACH mice showed profound rhizomelic dwarfism, a rounded skull, and kyphosis (arrow) in the cervico-thoracic spine. The severity of these phenotypes correlated with the dose of FGFR3^ACH and postnatal development. Lateral view of whole skeleton at the age of 1 month (A), 4 months (B), and 1 year (C). The enlarged view shows rounded skull at the age of 1 month (D), 4 months (E), and 1 year (F). The enlarged view shows kyphosis (arrow) in the cervico-thoracic spine in FGFR3^ACH/+ and FGFR3^ACH/ACH mice aged 1 month (G), 4 months (H), and 1 year (I). The enlarged view shows short, curved, and thick bones with widened diaphyses and flared metaphyses in the femurs of FGFR3^ACH mice at several developmental stages (J).