Figure 1.

Map of targeted open reading frames and diagram of PCR strategy. Degenerate nested primers (black triangles) were used to amplify part of the UL55 or UL56 open reading frame. The amplified fragments are represented by thin solid lines between the primer binding sites (A); Long-distance nested PCR was performed with specific primers (open triangles). The amplified fragments are represented by dashed lines between the primer binding sites (B); Fragments amplified in (A,B) were sequenced and assembled to a final contiguous sequence of 2.2 to 2.4 kb (C). At the top of the figure, the genomic locus spanning open reading frames UL55 and UL56 is depicted with open arrows. The arrowhead indicates the direction of transcription. The start of the ruler corresponds to the first base of the ORF UL56.