Class IV - Positive Strand RNA Animal Viruses

Class IV - Positive Strand RNA Animal Viruses

	Class IV - Positive Strand RNA Animal Viruses - The genome RNA has the same polarity as mRNA. Class IV viruses can be divided into two types, IVa and IVb. Class IVa. A single mRNA codes a polyprotein, which is then cleaved to form all the viral proteins. Picornaviruses - e. g. poliovirus.
Class IVb. Two forms of mRNA are synthesized: one is the same length as virion RNA and, be other is, arrangement of virion RNA. Togaviruses include the alpha viruses (group A), e.g. Sindbis virus and Semliki forest virus (SFV) and the flaviviruses (group B), e.g. dengue virus, yellow fever virus and the St. Louis encephalitis virus.

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Herpesviruses Herpesviruses And Their Infections Poxviruses Reoviruses Reovirus RNAs and Proteins Picornaviruses Strucures of Picornavirus During Morphogenesis Togaviruses (Arboviruses) Rhabdoviruses Proteins of the Vesicular Stomatitis Orthomyxoviruses Multiplication in RNA Viruses Rous Sarcoma Virus (RSV) Interferon