Phylogenetic tree of the open reading frames of the M and PA genes of the H6 influenza A viruses isolated in Eastern China. Viruses highlighted with the black triangles are characterised in this study. The tree was constructed using the neighbour-joining method of MEGA 5.0, with 1,000 bootstrap trials to assign confidence to the groupings.
Zhao et al. Virology Journal 2011 8:470 doi:10.1186/1743-422X-8-470