A continuous line of chicken embryo cells derived from a chondrocyte culture infected with RSV

A continuous line of chicken embryo cells was derived from a culture of chondrocytes infected with Rous sarcoma virus (RSV). These cells, designated as NA101, have reduced serum requirements and are able to grow in a semisolid medium. NA101 cells show the same phenotype as freshly RSV infected chondrocyte cultures, i.e. synthesis of fibronectin and type I collagen, elongated bipolar shape and absence of tumorigenicity following grafting onto the chorioallantoic membrane of embryonated duck eggs; thus they appear to be distinct from transformed fibroblasts. Neither NA101 cells nor freshly infected chondrocyte cultures synthesize type II or type X collagen, which are the differentiation markers of normal chicken chondrocytes in culture.