Persistent infection of a cell line of mouse origin after cell fusion by u.v.-inactivated Sendai virus

A cell line derived from Sendai virus-induced fusion of human adenocarcinoma and CBA mouse embryo cells and Sendai virus antigen (detected by immunofluorescence), together with bi-armed marker chromosomes, in 100% of the cells. After repeated passage, antigen-free cells carrying the same marker chromosomes appeared in the culture. Acrylamide gel analysis showed that all the Sendai virus antigens of antigen-positive cells were normal with the exception of the M protein. Antigen-negative cells contained no virus proteins and could be superinfected with wild-type virus, when all virus proteins appeared.