Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2019 May 6;374(1775):20180257. doi: 10.1098/rstb.2018.0257

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2019 The Authors.

Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.

PMC Copyright notice

Figure 1. — PB2 phylogeny of a stratified sample of all influenza subtypes. Tips in the circular neighbour-joining tree are coloured by host: blue, avian; pink, swine; orange, human; green, canine; brown, equine; purple, bat. The rings from inner to outer are: host-type, haemagglutinin subtype (H-type), neuraminidase subtype (N-type) and continent of isolation. The tree shows (clockwise) bats at the root, the avian—Eurasian lineage with many subtypes, human seasonal H1N1, H2N2 and H3N2 spread through all the continents, H1N1, H1N2, H3N2 swine influenza, the H1N1 pandemic swine influenza lineage in humans and swine, and the avian—Americas lineage with many subtypes.