Phylogeny and evolution of Newcastle disease virus genotypes isolated in Asia during 2008-2011
Phylogeny and evolution of Newcastle disease virus genotypes isolated in Asia during 2008-2011
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DOI：
10.1007/s11262-012-0738-5
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发表时间：
2012-08-01
期刊：
影响因子：
1.6
通讯作者：
Shamsara, Mahdi
中科院分区：
文献类型：
--
作者：
Ebrahimi, Mohammad Majid;Shahsavandi, Shahla;Shamsara, Mahdi
对2008-2011年亚洲地区分离的51株纽卡斯尔（ND）分离株的全长融合基因（F）进行了遗传分析。系统进化分析表明，亚洲地区家禽中的NDV基因型仍以VII型为主。VIIb亚型分布于伊朗和印度次大陆国家，而VIId亚型分布于远东国家。VIId亚基因型和VIIb亚基因型的非同义与同义替换比率分别为0.27和0.51，表明纯化/稳定化选择导致VIIb亚基因型的F基因的低进化速率。当比较这些亚基因型蛋白质序列时，存在局部正选择的证据。用Bayesian方法对ND病毒F基因中5个密码子进行后验概率分析，结果均> 90%，表明这些位点处于正选择状态。在正选择下识别位点;氨基酸取代的分类取决于其激进性和中性。结果表明，虽然大多数位点处于纯化选择中，可以被淘汰，但少数位于亚基因型特异区域的位点受到正选择。
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.