Research Article Effect of the PB2 and M Genes on the Replication of H6 Influenza Virus in Chickens

Copyright © 2014 Hiroichi Ozaki et al.This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. H6 subtype influenza viruses are commonly isolated fromwild aquatic birds.However, limited information is available regardingH6 influenza virus isolated from chickens. We compared the viral genome segment between A/chicken/Hong Kong/W312/97 (H6N1), which was able to grow in chicken trachea, and A/duck/Shantou/5540/01 (H6N2), which was isolated from wild aquatic duck, to explore the factors for effective replication in chicken. When chickens were inoculated with 7 + 1 reassortants (W312 background), the replication of viruses with PB2 and M genes derived from the duck strain was significantly reduced. Chimeras of PB2 and M proteins, encoding the C-terminal region of the PB2 protein and the M2 protein fromW312, were required for efficient replication in canine-derived (MDCK) cells and in chicken trachea. These results indicate that host range may be determined by some types of internal proteins such as PB2 and M2, as well as by surface glycoprotein like hemagglutinin. 1