Effects of cell shape on type X collagen gene expression in hypertrophic chondrocytes.
During endochondral ossification, small flat resting and proliferating chondrocytes mature into large round hypertrophic chondrocytes that synthesize a unique collagen, type X. We have asked whether this change in cell shape during chondrocyte maturation regulates type X collagen gene expression, using immature chick vertebral chondrocytes grown in monolayer or in suspension. The freshly isolated chondrocytes contained no type X collagen RNA, but after 30 days of culture, both attached and suspended cells contained a similar large amount. However, in cells that were grown in monolayer and then resuspended three days before harvest, type X collagen gene expression increased a further 6 fold. These results suggest that the change from a flat to a round shape that occurs during chondrocyte maturation in vivo may be important for maximal expression of the type X collagen gene.
Adams
S L
SL
Department of Anatomy and Histology, University of Pennsylvania School of Dental Medicine, Philadelphia.
Pallante
K M
KM
Pacifici
M
M
D000818:Animals; D002356:Cartilage / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D002478:Cells, Cultured; D002642:Chick Embryo; D003094:Collagen / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D006984:Hypertrophy
D003094:Collagen