FIG 2.

Transcripts originating from each MIE transcription start site give rise to mature IE1 and IE2 mRNAs. Mock-infected (Mock) or HCMV-infected MRC-5 fibroblasts were harvested at 72 h after infection. (A) Polysome-associated RNA was extracted from AD169-infected cells and reverse transcribed using a primer specific for either exon 4 (IE1) or exon 5 (IE2). The resulting cDNA was amplified using a primer specific for either IE1 or IE2 together with a primer specific for each UTR (the primers are indicated by the length [in base pairs] of their their 5′ UTR [UTR70, UTR136, UTR378, and UTR487]), and the PCR products were visualized on agarose gels. Reverse transcriptase was omitted in a set of samples [(-)RT] to ensure the absence of contaminating DNA. (B) Total RNA was extracted and analyzed as in panel A. (C) As in panel B, except cells were infected with the HCMV TB40/E strain (MOI of 3). The PCR products in panels A, B, and C were cloned and sequenced to ensure their specificity.