High C + G Content in Parapoxvirus DNA

Abstract

SUMMARYThe DNAs of eight parapoxviruses (four stomatitis papulosa viruses isolated from infected calves, a pseudocowpox virus isolated from a teat lesion of an infected cow and three orf viruses, one isolated from an infected sheep and two isolated from human infections) were analysed in CsC1 gradients. The mole of G+ C was calculated from the buoyant density and found to be approx. 63 % for all virus isolates examined. Parapoxvirus DNA thus has by far the highest G + C content of all poxvirus DNAs so far examined.Parapoxviruses form a group of morphologically dearly distinct viruses within the family Poxviridae. In contrast to the DNA of vaccinia virus (an orthopoxvirus) which is well characterized by its high mol. wt. of 122 X 10 6, (Geshelin & Berns, I974), presence of crosslinks at the termini (Berns & Silvermann, I97O; Geshelin & Berns, 1974) and a low G+ C content of 36 to ' 37 ~ (Joklik, I962a, b), very little is known about the genome of parapoxviruses. We have recently shown that the DNA of stomatitis papulosa virus has a tool. wt. of approx. 85 × Io 6 and that the ends are also cross-linked (Menna et ak I979).In order to characterize further the DNA of parapoxviruses we have calculated the mole of G + C of the DNAs of several isolates of parapoxviruses from the buoyant density obtained in analytical CsCl gradients.The following eight parapoxviruses were used in tfiis study: four stomatitis papulosa viruses (from infected calves), three orf viruses (one isolate from an infected sheep and two isolates from human infections) and one pseudocowpox virus (isolated from a teat lesion of an infected cow). The buoyant densities of the DNAs of the parapoxviruses was compared to the DNAs from two members of the orthopoxvirus genus, vaccinia (strain Elstree) and rabbitpox virus (strain Utrecht). The two orthopoxviruses were grown on the chorioallantoic membrane of developing chick embryos and the virions purified as described by Joklik 0962a). The parapoxvirus isolates were all grown on bovine foetal lung cells (Goldsmit & Barzilai, 1975). After virus adsorption for I h at 37 °C the cultures were further incubated until 90 ~ of the cells showed a c.p.e. The cultures were then frozen and thawed and the cells and viruses pelleted by ultracentrifugation. Virions were purified essentially as described by Joklik (1962a) for orthopoxviruses. Since the parapoxviruses banded in the upper third of the sucrose gradients in preliminary experiments, the procedure was slightly modified. Virions were pelleted through a cushion of 36 ~o sucrose for 2o rain at 26000 rev/min in a Beckman SW 40 rotor and banded in 25 to 4o ~ sucrose gradients for 25 rain at 23000 rev/min, also in a Beckman SW 40 rotor. In order to isolate the DNA of orthopoxviruses and parapoxviruses, virions were collected from sucrose gradients, pelleted by centrifugation for 3o min at 2500o g and resuspended in 50 mM-tris-HC1, pH 7"8, I mM-EDTA, 27 ~ sucrose and o'5 ~ SDS. The DNA was isolated by treatment of the virus suspension with 2o #g of proteinase K per ...

Western blot analysis of virus-specific antibody responses for capripox and contagious pustular dermatitis viral infections in sheep

“…Virusspecific antibodies in sera are routinely used to indicate exposure to virus and it is therefore important to have a serological assay for the differention of CPV and CPDV infections. The viruses can easily be differentiated from each other by electron microscopy [6], and genomic comparison [7]. However, a major common precipitating antigen shown to be present in strains of CPV also reacts with CPDV positive serum [8].…”

Conventional Bone Marrow-Derived Dendritic Cells Contribute to Toll-Like Receptor-Independent Production of Alpha/Beta Interferon in Response to Inactivated Parapoxvirus Ovis

“…63% GϩC. In contrast to the majority of the other poxviruses, which are AϩT-rich, PPV DNA thus has by far the highest GϩC content of all poxvirus DNAs (59). In electron microscopic pictures, PPVO displays a characteristic basket weave pattern, that distinguishes PPVO from other poxviruses (22).…”

Viral Vascular Endothelial Growth Factor Plays a Critical Role in Orf Virus Infection

“…However, the distinctive morphology of parapoxvirus virions and the high GϩC content of their genomes (44) suggest that a significant genetic divergence from other genera of this family has occurred. This suggestion has been confirmed by sequence analyses of the 140-kb orf virus genome (14,30).…”