Time-dependent increase in mCMV infection of cultured SMGs. A, C, E. β-gal (mCMV) staining of SMGs demonstrates a marked increase in viral infection with increased days in culture. B, D, F, G, H. Immunolocalization of viral IE1 protein. In E15 + 3 (B) and E15 + 6 (D) mCMV-infected SMGs, IE1 protein is localized to mesenchymal cells (m) and not epithelial cells (e). F, G, I. In E15 + 12 mCMV-infected SMGs, IE1 protein is seen in metaplastic stromal cells (mc), in a few epithelial cells (arrows) and in lumen-filling cells (*). H. J. DAPI staining of E15 + 12 mCMV-infected SMGs shown in G, I. Bar: A: 62 μm; B-F: 50 μm; G, H-J: 25 μm.