Scleral fibroblasts of the chick embryo differentiate into chondrocytes in soft-agar culture

• Published in: In vitro cellular & developmental biology Vol. 28A; no. 9-10; p. 603
• Main Authors: Watanabe, K, Yagi, K, Ohya, Y, Kimata, K
• Format: Journal Article
• Language: English
• Published: United States 01.09.1992
• Subjects: Agar; Alcian Blue; Animals; Cartilage - cytology; Cell Differentiation; Cells, Cultured; Chick Embryo; Clone Cells - cytology; Fibroblasts - cytology; Immunohistochemistry; Sclera - cytology; Staining and Labeling; Tolonium Chloride
• ISSN: 0883-8364
• DOI: 10.1007/BF02631034

Scleral fibroblasts, perichondrial cells of the scleral layer of the 12-day chick embryo, always manifest a fibroblastic morphology in monolayer culture. In soft-agar culture, these cells produce two types of colonies. One type of colony, F-type, consists of adherent fibroblastic cells, and the other, C-type, is composed of scattered round chondrocytic cells. Cells of the C-type colony are surrounded by a halo of extracellular matrix, positive with Alcian blue and with an antibody to cartilage-specific proteoglycan. When a single fibroblast clone in monolayer, derived from a single scleral fibroblast, is subcultured into soft agar, the cells give rise to both C-type and F-type colonies. Further, it was found that cells constituting F-type colonies eventually separate and become spherical, and the F-type colony converts to a C-type colony (C-type conversion). In regard to the C-type convertibility, the primary fibroblast clones were divided into four categories, early time differentiating, middle-time differentiating, late-time differentiating and nondifferentiating. This suggests that the scleral perichondrial layer of the 12-day chick embryo is composed of a variety of cells with different chondrogenic potentialities maintained in each individual cell.