| Abstract: | Although New Zealand Black mouse embryo and adult tissues show evidence of murine leukemia viral particles and antigens, efforts to demonstrate biological activity of a murine leukemia virus by standard methods have proved negative. Cocultivation of tissues of these mice with non-virus-yielding hamster cells transformed by Moloney sarcoma virus, however, has resulted in the rescue of a pseudotype sarcoma virus, presumably carrying the New Zealand Black mouse leukemia virus coat. This virus has an unusual host restriction, producing foci of cell alteration only in rat cells. |
