title: Dating the divergence of the infectious hematopoietic necrosis virus.
abstract: Infectious hematopoietic necrosis virus (IHNV) is an economically significant rhabdovirus that can cause severe disease to most salmonid fish. Phylogenetic analyses of worldwide IHNV isolates have defined five major genogroups. Herein, to further the understanding of the molecular epidemiology and evolution of IHNV, Bayesian coalescent analyses were conducted to the time-stamped coding sequences of the N, G and NV genes. The nucleotide substitution rates and the divergence times were assessed. Among the three genes, NV, the smallest one coding for a non-virion protein, was conferred the highest mean rate. Estimates for the G subsets based upon the five genogroups indicated that L and U evolved much slower than the others. Age calculations suggested that the first diversification event of the IHNV isolates analyzed might have happened before the notification of the disease during the early 1950s. Selection analyses suggested that the three genes were mainly subject to purifying selection. In addition, surveys of codon usage variation showed that the three genes had influences other than mutational bias.
authors.affiliation: College of Life Science, Northeast Forestry University, Harbin 150040, China.
authors.forename: Mei
authors.initials: M
authors.lastname: He
authors.forename: Nai-Zheng
authors.initials: NZ
authors.lastname: Ding
authors.forename: Cheng-Qiang
authors.initials: CQ
authors.lastname: He
authors.forename: Xue-Chun
authors.initials: XC
authors.lastname: Yan
authors.forename: Chun-Bo
authors.initials: CB
authors.lastname: Teng
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D030541:Databases, Genetic; D019143:Evolution, Molecular; D014644:Genetic Variation; D029142:Infectious hematopoietic necrosis virus / Q000145:classification / Q000235:genetics*; D018353:Rhabdoviridae Infections / Q000662:veterinary / Q000821:virology; D012487:Salmonidae / Q000821:virology; D014759:Viral Envelope Proteins / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
chemical_list: C104040:IHNVG protein, Infectious hematopoietic necrosis virus; C096112:NV protein, Rhabdovirus; D014759:Viral Envelope Proteins; D014764:Viral Proteins
keywords: IHNV; Substitution rate; TMRCA