Influenza A virus genome is comprised of 8 negative-sense RNA
segments, encoding 10 proteins (hemagglutinin (HA), neuraminidase
(N), membrane channel protein, nucleoprotein, matrix protein,
polymerase basic 1, polymerase basic 2, polymerase acidic protein,
nonstructural protein 1 and nonstructural protein 2). The HA
protein is categorized into 18 subtypes and confers the H number in
the influenza strain (e.g. H1, H3, etc). Similarly, the N protein
has 11 sub-types and confers the N number in the influenza strain
(e.g. N1, N2, etc.). During co-infection of two strains,
reassortment can occur to produce new strains of influenza.
|