Enveloped, spherical. Diameter from about 150nm nm. Negative-
stranded RNA linear genome, about 15-16 kb in size. Encodes for
eight proteins. The viral RNA dependent RNA polymerase binds the
encapsidated genome at the leader region, then sequentially
transcribes each genes by recognizing start and stop signals
flanking viral genes. mRNAs are capped and polyadenylated by the
L protein during synthesis. - Virus attaches to host cell
surface receptors through H glycoprotein. - Fusion with the
plasma membrane; ribonucleocapsid is released in the cytoplasm.
- sequential transcription, viral mRNAs are capped and
polyadenylated in the cytoplasm. - Replication presumably starts
when enough nucleoprotein is present to encapsidate neo-
synthetized antigenomes and genomes. - the ribonucleocapsid
interacts with the matrix protein under the plasma membrane and
buds, releasing the virion.