鸽源禽腺病毒XY20株Hexon全基因克隆与序列分析

Cloning and sequence analysis of the complete Hexon gene of pigeon-derived Avian adenovirus strain XY20

为了明确鸽源禽腺病毒主要致病性相关基因的分子特征,试验对Hexon基因分段进行PCR扩增,并在测序后拼接为完整的XY20株Hexon基因,通过DNAStar 7.1软件将其与从GenBank中选择的49株参考毒株的核苷酸和氨基酸进行序列比对,绘制系统进化树,分析氨基酸位点变异情况;通过SOPMA在线软件预测分析Hexon基因编码的Hexon蛋白的二级结构,通过http://www.cbs.dtu.dk/services/NetNGlyc/程序预测Hexon蛋白的N-糖基化位点。结果表明:XY20株Hexon基因序列全长为2814 bp,编码937个氨基酸;XY20株属于C群FAdV-4型,与各群代表毒株Hexon基因的核苷酸相似性在71.7%~100%之间,推导氨基酸序列相似性在76.8%~100%之间,与我国近几年禽腺病毒流行毒株GX-1、HB1510、HLJ 160826等的Hexon基因相似性为100%。与国外C群FAdV-4型毒株相比,XY20株的氨基酸中存在31个变异位点。XY20株Hexon蛋白的二级结构及11个N-糖基化位点与FAdV-4型早期毒株ON1相比没有发生明显变化。说明XY20株与早期FAdV-4型毒株Hexon蛋白抗原性一致,且极有可能源自鸡群FAdV-4型流行毒株。

To clarify the molecular characteristics of the main pathogenic genes of pigeon-derived avian adenovirus,and provide theoretical support for the prevention and control of pigeon adenovirus infection in pigeons.Hexon gene was amplified by PCR,and XY20 Hexon gene was spliced after sequencing.By comparing the nucleotide and amino acid sequences of 49 reference strains selected from Genbank with DNAStar7.1 software,phylogenetic tree was drawn to analyze the variation of amino acid sites.The secondary structure of Hexon protein encoded by Hexon gene was predicted and analysed;N-glycosylation site of Hexon protein was predicted by http://www.cbs.dtu.dk/services/NetNGlyc/.The results showed that the Hexon gene sequence of XY20 strain was 2814 bp,encoding 937 amino acids.XY20 strain belonged to FAdV-4 type C,and the nucleotide similarity between XY20 and Hexon gene was 71.7%~100%,and the derived amino acid sequence similarity was 76.8%~100%.The Hexon gene similarity was 100%with the avian adenovirus strains GX-1,HB1510 and HLJ 160826.There were 31 sites differences between XY20 strain and foreign group C FAdV-4 strains in 937 amino acids.The secondary structure of the hexon protein of XY20 strain and 11 glycosylation sites did not change significantly compared with the early FAdV-4 strain ON1.These results indicated that XY20 was consistent with the antigenicity of the hexacon protein of the early FAdV-4 strain,and it was very likely derived from FAdV-4 circulating strain in chickens.