The Simian varicella virus and varicella zoster virus genomes are similar in size and structure

Abstract

Simian varicella virus (SVV) DNA was purified from viral nucleocapsids and the molecular structure of the SVV genome was determined. SVV DNA was analyzed by agarose gel electrophoresis of BamHl, Bglll, EcoRl, and Pstl restriction endonuclease digests. SVV and varicella zoster virus (VZV) DNAs were demonstrated to have distinct restriction endonuclease profiles. Summation of the sizes of individual restriction endonuclease fragments indicate the size of SVV DNA is ≅121 kilobase pairs (kbp) or ≅76.8 megadaltons (Md). Electron microscopy, λ exonuclease analysis, and Southern blot DNA hybridizations were utilized to determine the molecular structure of the SVV genome and to construct restriction endonuclease maps. The results indicate that SVV DNA consists of a long component (L, ≅100 kbp) covalently linked to a short component (S, ≅20 kbp) which is composed of a unique short sequence (U s, 5.3 ± 0.7 kbp) bracketed by inverted repeat sequences (TR s and IR s, ≅7.2 kbp). The presence of 0.5 M Pstl restriction endonuclease fragments indicates that the S component may invert relative to the L component and that the genome exists in two major isomeric forms. The findings demonstrate that the SVV and VZV genomes are similar in size and structure.