GROWTH AND DIFFERENTIATION OF EPIDERMAL-CELLS FROM THE RAINBOW-TROUT ESTABLISHED AS EXPLANTS AND MAINTAINED IN VARIOUS MEDIA

Growth and a number of differentiated characteristics of cultured epidermal cells from the rainbow trout Oncorhynchus mykiss were compared using two commercially available serum-free media, a dermal substrate/serum free kit and a serum-containing medium which had been previously optimized for epidermal cell culture. Each medium supported short term growth over 15 days. Only the medium supplied for dermal substrate culture supported longer growth periods. This medium was supplied for use with a collagen/stromal substrate but gave good cultures even without the substrate. Differentiation, measured by examining mucous cells, cytokeratins, epidermal growth factor receptor, gap junction status and ultrastructure showed that serum-free media gave quantitatively and qualitatively superior expression and short term retention of differentiation over serum-containing medium. Epithelial cell growth with expression of differentiated characteristics can be maintained in primary culture in serum-free medium for at least as long as in serum-containing medium. This provides a useful technique for use when serum presence in medium is undesirable or proves toxic to the specialized cell type under investigation.