Genetic and molecular control of osterix in skeletal formation

AbstractOsteoblast differentiation is a multi‐step process where mesenchymal cells differentiate into osteoblast lineage cells including osteocytes. Osterix (Osx) is an osteoblast‐specific transcription factor which activates a repertoire of genes during differentiation of preosteoblasts into mature osteoblasts and osteocytes. The essential role of Osx in the genetic program of bone formation and in bone homeostasis is well established.Osxmutant embryos do not form bone and fail to express osteoblast‐specific marker genes. Inactivation ofOsxin mice after birth causes multiple skeletal phenotypes including lack of new bone formation, absence of resorption of mineralized cartilage, and defects in osteocyte maturation and function. Since Osx is a major effector in skeletal formation, studies on Osx gained momentum over the last 5–7 years and implicated its important function in tooth formation as well as in healing of bone fractures. This review outlines mouse genetic studies that establish the essential role of Osx in bone and tooth formation as well as in healing of bone fractures. We also discuss the recent advances in regulation ofOsxexpression, which is under control of a transcr