Phylogeny and evolution of Newcastle disease virus genotypes isolated in Asia during 2008-2011

作者：Ebrahimi Mohammad Majid^*; Shahsavandi Shahla; Moazenijula Gholamreza; Shamsara Mahdi

来源：Virus Genes, 2012, 45(1): 63-68.

DOI：10.1007/s11262-012-0738-5

• Newcastle disease
• Fusion gene
• Positive selection evolution

The full-length fusion (F) genes of 51 Newcastle disease (ND) strains isolated from chickens in Asia during the period 2008-2011 were genetically analyzed. Phylogenetic analysis showed that genotype VII of NDV still predominant in the domestic poultry of Asia. The sub-genotype VIIb circulated in the Iran and Indian sub-continent countries, whereas VIId sub-genotype existed in Far East countries. The non-synonymous to synonymous substitutions ratio was calculated 0.27 for VIId sub-genotype and 0.51 for VIIb sub-genotype indicates purifying/stabilizing selection which resulted in a low evolution rate in F gene of VIIb sub-genotype. There is evidence of localized positive selection when comparing these sub-genotypes protein sequences. Five codons in F gene of ND viruses had a posterior probability > 90% using the Bayesian method, indicating these sites were under positive selection. To identify sites under positive selection; amino acid substitution classified depends on their radicalism and neutrality. The results indicate that although most positions were under purifying selection and can be eliminated, a few positions located in sub-genotype specific regions were subject to positive selection.

• 出版日期2012-8