Further characterization of a thermosensitive transformation variant of mouse fibroblasts.
Temperature-sensitive (ts) variants that express phenotype at low (33 degrees) but not at high (38.5 degrees) temperature were isolated from a mouse fibroblast strain C3H2K cells. Among these variants, cloned ts-12B cells showed at 38.5 degrees a density-dependent inhibition of growth typical of normal fibroblasts cultured in vitro. However, at low temperature they lost this capacity and grew to a higher saturation density. The ts variant was also temperature-sensitive as regards serum requirement: it required a higher concentration of serum for growth at 38.5 degrees than at 33 degrees. However, the cells behaved at both temperatures like the parent strain, possessing anchorage-dependence for growth and fibronectin, whereas they were like transformed cells with respect to release of high fibrinolytic activity. No type-C virus core protein p30 was detected at either temperature. Thus, various parameters of transformation in vitro were independently regulated in these variant cells.
D000818:Animals; D001769:Blood; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D003470:Culture Media; D005343:Fibrinolytic Agents / Q000378:metabolism; D005347:Fibroblasts / Q000382:microbiology / Q000473:pathology; D005353:Fibronectins / Q000032:analysis; D051379:Mice; D009154:Mutation; D012190:Retroviridae / Q000302:isolation & purification; D013696:Temperature
D003470:Culture Media; D005343:Fibrinolytic Agents; D005353:Fibronectins