Sequence analysis of the leftward end of simian varicella virus (EcoRI-I fragment) reveals the presence of an 8-bp repeat flanking the unique long segment and an 881-bp open-reading frame that is absent in the varicella zoster virus genome

Simian varicella virus (SVV) causes varicella (chickenpox) in nonhuman prim ates, becomes latent in cranial and dorsal root ganglia, and reactivates to produce tester (shingles). Because the clinical and molecular features of SVV closely resemble those of varicella tester virus (VZV) infection of hum ans, SVV infection of primates has served as an experimental model of VZV p athogenesis and latency. The SVV genome has been completely mapped, but att empts to clone the 3600-bp EcoRI fragment located at the leftward end of th e virus genome have hitherto been unsuccessful. Herein, we report the cloni ng and the complete nucleotide sequence of this region. Comparison of the S VV and VZV sequences in this region revealed an 8-bp inverted repeat sequen ce flanking the unique long segment of the SVV genome; an 879-bp open-readi ng frame (ORF) A in SVV that is absent in VZV but has 42% amino acid identi ty to SVV ORF 4 and 49% to VZV ORF 4; a 342-bp ORF B in SVV with 35% amino acid identity to a 387-bp ORF located to the left of ORF 1 on the VZV genom e; and a 303-bp ORF in SVV with 27% amino acid identity to VZV ORF 1. No ho mologue of VZV ORF 2 was detected. Transcripts specific for ORFs A and B we re present in SVV-infected cells in culture and in acutely infected monkey ganglia. Overall, there are more than 2000 bp of DNA in the SVV genome that are absent in the VZV genome. (C) 2000 Academic Press.