@entity6446 ( @entity6446 ) is a form of aberrant endochondral ossification in @entity1573 , in that a plug of avascular cartilage ( @entity75 ) is formed within the growth plate. Histologically, the lesion is filled with apparently transitional chondrocytes that have been unable to differentiate to @entity1184 chondrocytes. We have examined the spatial expression of mRNAs for type X collagen, @entity70389 (Ihh) and @entity46200 ( @entity46200 ) in the @entity6446 growth plate by in situ hybridization in order to ascertain at which stage chondrocyte differentiation is arrested in @entity6446 . In the normal growth plate, type X collagen mRNA was expressed by both prehypertrophic and @entity1184 chondrocytes. @entity70389 mRNA was detected in a band of prehypertrophic chondrocytes and @entity46200 expression was localized to a narrow band of prehypertrophic chondrocytes and in osteoblasts within the diaphysis. In @entity6446 sections, collagen X expression was seen within differentiating cells, within a small number of lesion cells, and within @entity1184 chondrocytes on the diaphyseal side of the lesion. Ihh expression was also seen within the differentiating cells and throughout the lesion. These data indicate that chondrocyte differentiation is arrested at the transitional stage just prior to @entity1184 . Contrary to the previously reported @entity46200 expression patterns in @entity6446 chicks by immunohistochemistry, @entity46200 mRNA was not detected in the @entity75 . This observation probably reflects the cessation of @entity46200 gene expression by chondrocytes in the more severe @entity6446 lesions. The results from the present study also imply that the arrest of cell differentiation in @entity6446 is independent of @entity46200 and that endochondral ossification in the post-hatch avian growth plate may involve additional regulatory pathways.

Expression of type X collagen, XXXX and parathyroid hormone related-protein in normal and tibial dyschondroplastic @entity1573 growth plates.

@entity75 :: ('MESH:D001927', 'Disease') :: ['TD lesion'] @entity1184 :: ('MESH:D006984', 'Disease') :: ['hypertrophic', 'hypertrophy'] @entity1573 :: ('9031', 'Species') :: ['chickens'] @entity46200 :: ('396281(Tax:9031)', 'Gene') :: ['PTHrP', 'Parathyroid Hormone-related protein'] @entity6446 :: ('MESH:D004687', 'Disease') :: ['TD', 'Tibial dyschondroplasia'] @entity70389 :: ('395801(Tax:9031)', 'Gene') :: ['Indian hedgehog', 'Indian Hedgehog']
@entity70389 :: (395801(Tax:9031),Gene) :: ['Indian hedgehog']
