The proliferation of chondrocytes in mice
Controlled by PHRP and Ihh
==>
PHRP secreted signaling protein：
1.Secreted by the chondrocytes and
perichondrial cells at the ends of the
prospective bones
2.Stimulates proliferation of chondrocytes
Prevent the expression of Ihh
Ihh (Indian hh)：
1.Cells move out of the zone of influence of
PHRP →stop proliferation→start exp Ihh��
→Become hypertrophic
2.FGF produced in the perichondrium→��
increased Ihh exp and suppress the cell
proliferation
