Systematic Veterinary Virology

REPLICATION

• Typical of other orbiviruses under reoviridae. The virus replicates in the cytoplasm. The virus enters into the cell through endocytosis. This is followed by partial uncoating.
• AHSV is inactivated if complete uncoating occurs. Early transcription of the d/s RNA genome by viral polymerase occurs inside this sub-viral particle. The various genome segments are transcribed/translated at different frequencies.
• Transcription occurs in two stages, primary and secondary. Only (-) sense strands are transcribed, resulting in synthesis of (+)sense mRNAs, which are capped inside the core. These mRNAs leave the core and are translated in the cytoplasm.
• The genome is replicated in the cytoplasm in a conservative fashion. An excess of (+)sense strands are produced, which serve as late mRNAs and as template for (-)sense strand synthesis (i.e. each (-) strand leads to many (+) strands - not one-for-one as semi-conservative replication).
•  The mechanism responsible for segregation of the various genome segments into developing particles is not known.