the novel mmtv variants obtained from murine , rat , feline , canine , and human cells showed no overt evidence of recombination with endogenous type-c viruses in that they retained their antigenic reactivities in group-specific radioimmunoassays for mmtv polypeptides , and were unreactive for type-c virus proteins when tested by radioimmunoassays and dna polymerase assays .
C0017279
antigenic
C0042776
virus