Cdc42 (
cell division cycle 42) is ubiquitously expressed
small GTPases belonging to the Rho
family of
proteins. Previously, we generated
limb bud mesenchyme-specific Cdc42 inactivated
mice (Cdc42 conditional
knockout mice; Cdc42â¯fl/fl; Prx1-Cre), which showed short
limbs and cranial
bone deformities, though the mechanism related to the
cranium phenotype was unclear. In the present study, we investigated the
role of Cdc42 in cranial
bone development. Our results showed that loss of Cdc42 caused a defect of intramembranous
ossification in cranial
bone tissues which is related to decreased expressions of
cranial suture morphogenesis genes, including Indian
hedgehog (Ihh) and
bone morphogenetic proteins (BMPs). These findings demonstrate that Cdc42
plays a crucial
role in cranial
osteogenesis, and is controlled by Ihh- and BMP-mediated signaling during
cranium development.