Abstract
It has been demonstrated that fibroblast growth factor receptors are key regulators of endochondral bone growth. However, it has not been determined what fibroblast growth factor ligand(s) (FGFs) are important in this process. This study sought to determine whether FGFs 1, 2, 4, 5, 6, 7, 8, 9, and 10 were capable of stimulating avian chondrocyte proliferation in vitro. We have found that FGFs 2, 4, and 9 strongly stimulate avian chondrocyte proliferation while FGFs 6 and 8 stimulate proliferation to a lesser extent. RTβPCR indicates that FGFβ2 and FGFβ4 are expressed in the postnatal avian epiphyseal growth plate (EGP) while FGFβ8 and FGFβ9 are not. Thus, FGFβ2 and FGFβ4 stimulate chondrocyte proliferation and are both present in the EGP. This suggests that FGFβ2 and FGFβ4 may be important ligands, in vivo, for the regulation of endochondral bone growth. These observations coupled with our observation that multiple avian FGF receptors (Cek1, Cek2, Cek3, and FREK) are expressed in proliferative chondrocytes highlights the complexity of FGF signaling pathways in postnatal endochondral bone growth. J. Cell. Biochem. 84: 359β366, 2002. Β© 2001 WileyβLiss, Inc.