Fig. 2. Kinetics of GPCMV growth in the placental tissue slices. (A) DNA samples were prepared from the placental tissue slices infected with GPCMV-SG (triangles) or GPCMV-RFP (circles) using a commercial kit (QIAGEN), and viral and cellular DNAs were quantified by real-time PCR assays as described in Supplementary Material. Viral loads are shown as viral copy numbers per 1 105 cells. Means of four placental tissue slices at each time point and standard deviations (SD) are shown. (B) Tissue slices were prepared from GP placentas at 4-wk GA (left columns) and at 6-wk GA (right column), and infected with GPCMV-RFP in 6 well-plates. BF: bright field, FL: fluorescent field. Lines indicate the boundaries of the placental slices. Red fluorescence shows viral localization in the slices. (C) Histology of the placental tissues that were obtained from 4wk-GA animals, infected with GPCMVd9K-WT, -GP129Stop, -GP131Stop, or -GP133Stop, and then cultured for 7 days. Staining with hematoxylin and eosin (HE) and immunohistochemical staining with antibodies against GPCMV antigens (monoclonal antibody g-1 and polyclonal antibodies against IE) are shown. (D) Means and standard deviations of viral loads in the placental tissues infected with GPCMVd9K-WT, -GP129Stop, -GP131Stop, or -GP133Stop at 5 days after infection are shown as viral copy numbers per 1 105 cells.