Collagen expression during XXXX cell line-induced endochondral @entity3478 .

@entity14641 @entity3478 @entity5 @entity19 @entity1413
Collagen immunotyping by indirect immunofluorescence was performed in order to investigate the sequential development of bone formation. @entity5 were obtained after subcutaneous injection of 3/A/1D-1 @entity14641 cell line into 129/Sv @entity19 (Nicolas et al., 1980). Frozen sections of developing @entity5 were incubated with specific antibodies directed against Types I, II, III, IV, and IX collagens. On Day 9, the expression of @entity1413 was correlated with the proliferation of mesenchymal cells. From Day 10, chondrogenesis was characterized by the occurrence of cartilaginous collagens, Types II and IX, in the cartilage matrix. Type IV collagen was also detected in focal areas and revealed vascular invasion of the @entity5 . On Day 13, osteogenesis was demonstrated by the presence of Type I collagen in the bone matrix coating the surfaces. Immunolocalization of Type III collagen on the hemopoietic elements corresponded with the bone remodeling. The sequential transitions of collagen types confirm the development of an endochondral @entity3478 . These results suggest that 3/A/1D-1 @entity14641 cell line constitutes a valuable system for in vitro study of endochondral bone formation and cell differentiation.
