A Full Expression of the Genome of Rous Sarcoma Virus in Heterokaryons Formed after Fusion of Virogenic Mammalian Cells and Chicken Fibroblasts

Abstract

Summary Immunofluorescence and autoradiography showed that all heterokaryotic cells formed after cell fusion of virogenic mammalian cells and indicator chicken cells induced by Sendai virus produced Rous sarcoma virus coat antigen. Homokaryons and mononuclear cells of both types were negative in the immunofluorescence test. Similarly, all tested single heterokaryons obtained by visually controlled cell fusion produced infectious Rous sarcoma virus. Virus coat antigen or infectious virus was not formed in virogenic cells or chicken fibroblasts agglutinated but not fused in the mixture with Sendai virus, or in heterokaryons obtained after fusion of virogenic cells with chicken erythrocytes; including heterokaryons containing ‘reactivated’ chicken erythrocyte nuclei. Heterokaryons formed after fusion of virogenic cells with chicken fibroblasts are permissive cells for Rous sarcoma virus, and play a key role in the Rous sarcoma virus rescue process.