Long intervals of stasis punctuated by bursts of positive selection in the seasonal evolution of influenza A virus.

ABSTRACT:

Background

The interpandemic evolution of the influenza A virus hemagglutinin (HA) protein is commonly considered a paragon of rapid evolutionary change under positive selection in which amino acid replacements are fixed by virtue of their effect on antigenicity, enabling the virus to evade immune surveillance.

Results

We performed phylogenetic analyses of the recently obtained large and relatively unbiased samples of the HA sequences from 1995-2005 isolates of the H3N2 and H1N1 subtypes of influenza A virus. Unexpectedly, it was found that the evolution of H3N2 HA includes long intervals of generally neutral sequence evolution without apparent substantial antigenic change ("stasis" periods) that are characterized by an excess of synonymous over nonsynonymous substitutions p

SUBMITTER: Wolf YI 

PROVIDER: S-EPMC1647279 | biostudies-literature | 2006 Oct

REPOSITORIES: biostudies-literature