In vitro culture of cloned hamster melanoma cells containing R-type virus.

A transplantable melanoma of golden Syrian hamsters was grown in tissue culture and four stable cell lines were obtained by cloning techniques. Cells of these lines differ from each other in growth patterns as well as in production of radial-type virus and synthesis and degradation of melanosomes. Cells of one line (KF) produced large amounts of virus and little or no pigmented melanosomes, which were degraded in the early stages of formation. Another cell line (WE) produced virtually no virus but melanosome formation remained intact. The other two cell lines produced varying amounts of both virus and melanosome and degraded pigment in "melanosome complexes."