An in vitro study of the oncogenic effects of two variants of avian sarcoma virus B77 on rat embryonal fibroblasts.

Two variants of avian sarcoma virus B77 have been tested for their heteroinductive oncogenic in vitro effects on rat embryonal cells. Variant 22-B77V belonging to subgroup B, had been cultured for a long time exclusively on its original host, i.e. on chicks, before being used in the study. This variant of B77V yielded negative results in repeated experiments on rat cells. Variant 55-B77V belonging to subgroup C and which had been made to pass through rat cells, caused a malignant transformation in the latter. The resultant type of this interaction were virus-producing tumorous cells (designated LWF B55). This study present some of the basic characteristics of these cells.