Influenza A and B viruses have eight RNA segments of negative polarity, whereas the genomeChoose segments to browse targeting microRNAs!
of the influenza C virus consists of seven RNA segments, each of which encodes PB2, PB1, P3, haemagglutininˇVesterase (HE), nucleoprotein (NP), matrix (M1) protein and CM2, and non-structural proteins (NS1 and NS2)(Lamb & Krug, 2001). PB2, PB1 and P3 are subunits of the RNA polymerase of the virus. HE glycoprotein, which has receptor-binding, acetylesterase and fusion activities, forms the spike on the virion (Herrler & Klenk, 1991).NP participates in forming ribonucleoproteins (RNPs) with virus RNA (vRNA), PB2, PB1 and P3. M1 is abundantly present beneath the envelope, which gives rigidity to the virion. CM2 is the second membrane protein of the virus, and has been demonstrated to possess ion-channel activity (Hongo et al., 2004). Although the function of NS1 remains to be clarified, NS2 is a nuclear export protein of the virus (Paragas et al., 2001)[Text from Yasushi Muraki et al., 2004]