EXPLANATION OF PICTURE
The green core ( RNP - ribonucleoprotein
) contains the genetic information of the virus wrapped up in protein. This combination
of gentic material and protein is called the nucleocapsid. In influenza, the nucleocapsid
is helical. The genetic information is stored as single stranded -ve sense RNA. The
full complement of genetic information is called the genome and in influenza the
genome is divided into eight segments. These segments are assumed to link together
( possibly in an ordered fashion ) to form a helix when the virus assembles at the
cell surface. Overlying the nucleocapsid is a layer of matrix protein, M1,
shown in purple. Overlying the matrix is the viral envelope (blue-green and
edged in yellow) derived from the host cell membrane ( the nucleocapsid and the matrix
proteins become wrapped in cell membrane as they bud from the infected cell ). The
characteristic "spikes" of the influenza virus are haemagglutinin.
They radiate all over the surface and are interspersed (in some types) by clusters
of neuraminidase. These (HA and NA) molecules are thought to pass through
the envelope and interact with the underlying matrix protein, M1
FOR INFORMATION ON VIRUSES ENTERING CELLS please see
virus
entry into animal cells from
Ed
Rybicki.
