Submitted to: Book Chapter
Publication Type: Review Article
Publication Acceptance Date: 6/1/1999
Publication Date: N/A
Citation: N/A Interpretive Summary: Satellite viruses are small pieces of RNA which rely on a much larger, genetically distinct, "helper" RNA virus to multiply. The satellite viruses contain very little genetic information, only one or two genes are present. Each satellite virus has a gene that allows for production of a "coat" protein. This protein wraps around and protects the virus RNA. The presence of the satellite viruses in an infection can cause changes in host symptoms, ranging from reduced to severe reactions. The origins of these satellite viruses remain a mystery, however, they highlight the diversity of viral parasites and the ability of RNA to undergo rapid changes. This information will benefit scientists that are working towards methods for reducing the economic impact of the diseases caused by viruses.
Technical Abstract: Nearly 40 years ago, Kassanis and Nixon described two kinds of particles in tobacco necrosis virus (TNV) infections that differed in size, and thus seemed to be separate viruses. The smaller component was demonstrated to depend on the larger autonomous virus for its multiplication, and hence was designated a satellite virus, satellite tobacco necrosis virus (STNV). This discovery quickly stimulated research in several areas of biology and chemistry with a focus on relationships, pathology, transmission and interdependence of STNV and TNV. After the realization of the satellite nature of STNV, identification of other satellite viruses was remarkably slow compared to the rates of discovery of new viruses, satellite RNAs, and viroids. More than 15 years passed before a second satellite virus, satellite panicum mosaic virus (SPMV; Fig. 1), was described. A satellite virus particle associated with maize white line mosaic virus (MWLMV) that constitutes a a third distinct satellite virus was subsequently identified. A fourth satellite virus, satellite tobacco mosaic virus (STMV), naturally occurs in Nicotiana glauca infected with the rod- shaped tobacco mosaic virus.