Evolutionary process of the novel H7N9 virus isolated in China in 2013.

Reassortment events on the six internal genes of the novel H7N9 viruses were analyzed based on the entire sequences of 221 influenza viruses using the RDP, GENECONV and MaxChi suites within the RDP3 software. In order to enhance the credibility of the results, the highest P value was set as 0.01.

Note: A/brambling/Beijing/16/2012 (H9N2) -like strains including A/chicken/Shangdong/01/2009, A/chicken/Jiangsu/Q3/2010, A/chicken/Zhejiang/611/2011, A/chicken/Shanghai/C1/2012, A/chicken/Zhejiang/329/2011 and A/chicken/China/AH-10-01/2010. A/environment/Zhejiang/16/2013 (H9N2) -like strains including A/environment/Zhejiang/9/2013, A/environment/Zhejiang/13/2013, A/environment/Zhejiang/14/2013, A/environment/Zhejiang/16/2013. A/chicken/Dawang/1/2011 (H9N2)-like strains including A/chicken/Shuanggou/1/2011 (H9N2) and A/pigeon/Xuzhou/1/2011. The eight genes of different strains were shown in different color.