Cbfa1, a transcription factor for osteoblast differentiation and bone formation

Cbfa1, originally cloned from fibroblasts, was preferentially expressed in the osteoblast lineage. Cbfa1-deficient mice completely lacked both intramembranous and endochondral ossification, and osteoblast differentiation was blocked in the mutant mice. Further, the Cbfa1 expression in nonosteoblastic cells induced osteoblastic markers in vitro. Therefore. Cbfa1 is an essential transcription factor for osteoblast differentiation. The skeletal changes of heterozygously mutated mice of the Cbfa1 locus were similar to that of cleidocranial dysplasia, which is a dominantly inherited disease. and the mutations of the CBFA1 locus were identified in patients with cleidocranial dysplasia.