Identification of a 30S RNA with properties of a defective type C virus in murine cells

Abstract
A novel species of 30S RNA was detected in a variety of mouse cell lines [fibroblast 3T3 and embryo Sc-1]. The 30S RNA is specifically packaged by helper-independent type C viruses propagated in such cells. Nucleic acid hybridization detects no homology between the 30S RNA and the genomic RNA of helper-independent mouse type C viruses. The properties of the 30S RNA suggest that it is a defective endogenous mouse type C virus and that it is analogous to a previously described class of defective endogenous rat type C virus, which was shown previously to be the progenitor of Kirsten and Harvey murine sarcoma viruses.