Figure 1.

Schematic representation of the JC Virus archetype strain CY, control region. Green boxes indicate the 64 and 23 base pair sequences that are not present in the Mad1 strain within the 98 base pair promoter/enhancer sequence, now divided into three empty gray boxes of 25, 55, and 18 base pairs. Arrows indicate the direction of early and late gene transcription. ORI represents the origin for viral DNA replication. The nucleotide sequence of the control region is shown below, depicting the 64 and 23 insertions (green boxes).