Sequence variation of the glycoprotein gene identifies three distinct lineages within field isolates of viral haemorrhagic septicaemia virus, a fish rhabdovirus

• Published in: Journal of general virology Vol. 78; no. 11; pp. 2837 - 2846
• Main Authors: Benmansour, A, Basurco, B, Monnier, AF, Vende, P, Winton, JR, de Kinkelin, P
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01.11.1997; Microbiology Society
• Subjects: Amino Acid Sequence; Animals; Biological Evolution; Brackish; Fishes - virology; Freshwater; Genes, Viral; Genetic Variation; Life Sciences; Marine; Microbiology and Parasitology; Molecular Sequence Data; Oncorhynchus mykiss; Rhabdoviridae; Rhabdoviridae - genetics; Sequence Alignment; Sequence Analysis; Vira; Viral Envelope Proteins - genetics; viral haemorrhagic septicaemia virus; Viral hemorrhagic septicemia virus; Virology
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-78-11-2837

A Benmansour, B Basurco, AF Monnier, P Vende, JR Winton and P de Kinkelin Institut National de la Recherche Agronomique, Unite de Virologie et Immunologie Moleculaires, Jouy-en-Josas, France. abdenour@biotec.jouy.inra.fr To evaluate the genetic diversity of viral haemorrhagic septicaemia virus (VHSV), the sequence of the glycoprotein genes (G) of 11 North American and European isolates were determined. Comparison with the G protein of representative members of the family Rhabdoviridae suggested that VHSV was a different virus species from infectious haemorrhagic necrosis virus (IHNV) and Hirame rhabdovirus (HIRRV). At a higher taxonomic level, VHSV, IHNV and HIRRV formed a group which was genetically closest to the genus Lyssavirus. Compared with each other, the G genes of VHSV displayed a dissimilar overall genetic diversity which correlated with differences in geographical origin. The multiple sequence alignment of the complete G protein, showed that the divergent positions were not uniformly distributed along the sequence. A central region (amino acid position 245-300) accumulated substitutions and appeared to be highly variable. The genetic heterogeneity within a single isolate was high, with an apparent internal mutation frequency of 1.2 x 10(-3) per nucleotide site, attesting the quasispecies nature of the viral population. The phylogeny separated VHSV strains according to the major geographical area of isolation: genotype I for continental Europe, genotype II for the British Isles, and genotype III for North America. Isolates from continental Europe exhibited the highest genetic variability, with sub-groups correlated partially with the serological classification. Neither neutralizing polyclonal sera, nor monoclonal antibodies, were able to discriminate between the genotypes. The overall structure of the phylogenetic tree suggests that VHSV genetic diversity and evolution fit within the model of random change and positive selection operating on quasispecies.