Summary.
Phylogenetic analysis was carried out for genes encoding hemagglutinin (HA) (24 new and 25 previously reported sequences) and nonstructural proteins (NS) (22 new and 14 previously reported sequences) of influenza B virus isolates obtained from 1940 to 1999. Two antigenically and genetically distinct HA lineages are presently known to exist. Divergence into these two lineages was estimated to have occurred around 1969. Phylogenetic analysis of NS genes revealed that their phylogenetic relationships were not linked to the two HA lineages but suggested that reassortment of viral genes between the viruses of two HA lineages had occurred. In addition two distinct NS lineages which were not linked to the two HA lineages were observed. Viruses isolated after 1997 formed their own lineage in combination with B/Houston/84 while other virus isolates obtained from 1973 to 1995 comprised the other NS lineage.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Accepted May 26, 1999 Received March 26, 1999
Rights and permissions
About this article
Cite this article
Luo, C., Morishita, T., Satou, K. et al. Evolutionary pattern of influenza B viruses based on the HA and NS genes during 1940 to 1999: origin of the NS genes after 1997. Arch. Virol. 144, 1881–1891 (1999). https://doi.org/10.1007/s007050050712
Published:
Issue Date:
DOI: https://doi.org/10.1007/s007050050712