Two biotypes of bovine viral
diarrhea-mucosal
disease virus are present in nature: one that induces cytopathology in infected bovine cells and the other that infects cells without overt cytopathology.
Infections with both types of virus yield similar amounts of infectious progeny virus. Field and laboratory isolates of both biotypes of bovine viral
diarrhea (BVD) virus were analyzed by radioimmunoprecipitation and
polyacrylamide gel electrophoresis of infected
cell extracts. The noncytopathic biotype BVD (NCB-BVD) virus isolates can be differentiated from cytopathic biotype BVD (CB-BVD) isolates on the basis of peculiar
polypeptide profiles they induce in the infected cell. The most abundant
polypeptide in CB-BVD infected cells is the 80K
polypeptide. NCB-BVD virus-infected cells lack the 80K
polypeptide and induce a predominant 118K
polypeptide. D-[2-3H]
Mannose labeling of cells infected with NCB-BVD indicated that at least three
polypeptides are N-glycosylated: 75K, 56K-58K, and 48K. In addition the sizes and ratios of the
glycoproteins induced by all virus isolates showed a marked variation. We present evidence indicating that there is remarkable heterogeneity among the field viral isolates of BVD and this methodology is of potential value for molecular epidemiology studies.