Virus Genes

, Volume 15, Issue 1, pp 53–59

Evolutionary Analysis of Influenza C Virus M Genes

Authors

  • Yuichiro Tada
    • Department of BacteriologyYamagata University School of Medicine
  • Seiji Hongo
    • Department of BacteriologyYamagata University School of Medicine
  • Yasushi Muraki
    • Department of BacteriologyYamagata University School of Medicine
  • Kanetsu Sugawara
    • Department of BacteriologyYamagata University School of Medicine
  • Kiyoto Nakamura
    • Department of BacteriologyYamagata University School of Medicine
  • Fumio Kitame
    • Department of NursingYamagata University School of Medicine
Article

DOI: 10.1023/A:1007915215958

Cite this article as:
Tada, Y., Hongo, S., Muraki, Y. et al. Virus Genes (1997) 15: 53. doi:10.1023/A:1007915215958

Abstract

The previous study of the 25 hemagglutinin-esterase (HE) glycoprotein genes of influenza C viruses identified four discrete lineages represented by C/Yamagata/26/81, C/Aichi/1/81, C/Aomori/74 and C/Mississippi/80, respectively. Here we compared the M gene sequence among the 24 viruses isolated between 1964 and 1991. A phylogenetic analysis showed that these genes have evolved into three distinct lineages. Lineage I included most of viruses with the HE genes of C/Yamagata/26/81-related lineage. The predominant members of lineage II were viruses having the HE genes of either C/Aichi/1/81- or C/Mississippi/80-related lineage. Lineage III contained only C/Aomori/74. Phylogenetic positions of several strains (C/Yamagata/64, C/Kanagawa/1/76, C/Miyagi/77 and C/Nara/1/85) were different between the M and HE gene trees, suggesting that they are reassortants. Furthermore, phylogenetic relationships between C/Mississippi/80-like and C/Aichi/1/81-like viruses were much closer for the M gene than the HE gene, raising the possibility that these two virus groups are genetically related by a reassortment event. Nucleotide changes in the M genes occurred at about 7% positions with a uniform distribution throughout the molecules. However, the predicted amino acid sequence of the matrix protein (M1) was conserved almost completely among the isolates analyzed. The amino acid sequence of the second protein (CM2) encoded by M gene was also highly conserved, but was more divergent than the M1 protein sequence, suggesting that the two M gene products are evolving differently in response to selective pressures or structural and functional constraints.

influenza C virusmatrix protein geneevolutionM1 proteinCM2 proteinreassortment

Copyright information

© Kluwer Academic Publishers 1997