Molecular characteristics of the untranslated segment-specific region of the hemagglutinin segments in H5N6 and H7N9 influenza viruses in Shenzhen

Abstract

Objective Exploring the molecular characteristic of global and Shenzhen district H5N6 and H7N9 influenza viruses HA untranslated regions(UTRs). Methods Mega7.0 and DNAStar 7.1.0 were used to construct phylogenetic tree and nucleotide analysis. Results From 2014 to 2015, 3 strains of H5N6 influenza virus from Shenzhen were compared with the other H5NX influenza viruses, the nucleotide homology of HA-3’UTR was 77.4%-100%, which did not have obvious mutated sites. The nucleotide homology of H5N6-HA-5’UTR was 91.7%-100%, and the sites of 24 and 31 sites were mutated. From 2013 to 2014, 11 strains of H7N9 influenza virus from Shenzhen were compared with the other H7NX influenza viruses, the nucleotide homology of H7N9-HA-5’UTR was 76.8%-100%, which had multi-mutated sites on 2-6, 9, 10, 12 and 15-17 positions. Conclusions HA-UTR from human-infected H5N6 and H7N9 influenza viruses isolated in Shenzhen district has unique molecular characteristics, its conserved region has relatively high homology and the segment-specific region has genetic polymorphism. Key words: H5N6 influenza virus; H7N9 influenza virus; Hemagglutinin(HA); Untranslated region; Homology; Polymorphism