Expression of late viral functions in SV40-infected rat-monkey somatic cell hybrids

Somatic cell hybrids between a rat hepatoma cell line and an SV40-transformed African green monkey kidney cell line (T22 TK-) have been isolated and their response to infection by SV40 virus characterized. The parental rat cells are nonpermissive to productive infection by SV40, while the parental monkey cells, which are T-antigen positive and capsid antigen negative, are permissive to productive infection. Hybrid clones, which had segregated monkey chromosomes, were infected with SV40 virus, and some clones were found to be negative for SV40 capsid antigen production while other clones were positive. Capsid antigen-positive clones production while other clones were positive. Capsid antigen-positive clones produced little or no form I SV40 DNA, no infectious virus, and were not capable of rescuing SV40 from SV40-transformed mouse cells. Such hybrids, which produce late viral proteins in the absence of mature progeny viral DNA may be useful in the study of control of SV40 RNA transcription.