Document Type

Thesis - Open Access

Award Date

1974

Degree Name

Master of Science (MS)

Department

Biology and Microbiology

Abstract

The subject of this investigation is the Aedes albopictus (Aal) cell line infected with Venezuelan equine encephalomyelitis (VEE) virus, a group A arbovirus. This cell-virus system is an ideal choice for both types of analysis. Certain of the group A arboviruses have been looked at as "models" for ribovirus replication and thus have several advantages for an FNA study. The genome is a single strand of RNA containing only about a dozen cistrons, the virions contain only one polypeptide in the nucleocapsid and one in the envelope, and infectious RNA is easily isolated and titrated by sensitive plaque assay. In addition, VEE infected Aal cells exhibit a noncytocidal response and are thus ideally suited for the volume distribution profile study. The A. albopictus cell s were employed for several reasons. First, the A albopictus mosquito can function as a vector for the VEE virus. Second, the A. albopictus cell line was a recent development and little was known about virus replication in these cells. Third, these cells do not exhibit CPE upon infection with VEE. Fourth, this cell-virus system provided a model by which other noncytocidal cell-virus systems could be compared. There is a definite need for the RNA analysis. The mechanism of single-strand RNA virus replication has been under intensive study in recent years; the results of which could possibly lead to the means by which RNA virus infections could be prevented. Certainly, some of the most destructive viruses, in terms of human misery and economic considerations, are the single-strand RNA viruses. These include polio, rabies, yellow fever, influenza, mumps, measles, and encephalitis viruses. In addition, a large number of the known animal cancer viruses are single-strand RNA viruses. Virtually all the experimental evidence supporting the current hypothesis of ribovirus replication is based on virus infections in cell lines exhibiting cytocidal response. The function of the RNA analysis in this investigation is to determine if the mode of ribovirus replication in cells exhibiting the noncytocidal response is similar to the mechanism of ribovirus replication in cells exhibiting a cytocidal response. In order to accomplish this goal, infected Aal cells were treated with Actinomycin D to inhibit DNA dependent RNA replication, treated with tritiated uridine supplemented media, and allowed to incubate. At various times post-infection, the virus-specific RNA was extracted from the cells with phenol-SDS. The different types of RNA isolated was determined by polyacrylamide gel electrophoresis of the molecules. The gels were then sectioned, and each section assayed for radioactive RNA species.

Library of Congress Subject Headings

Virology -- Research

Viruses

Cells

Format

application/pdf

Number of Pages

156

Publisher

South Dakota State University

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