口蹄疫病毒O型Mya98谱系猪源毒株和牛源毒株全基因组的比较

Comparison of the full-length genomes of Mya98 lineage of type O foot-and-mouth disease viruses isolated from pigs and cattle

为了查明我国新流行的口蹄疫病毒(FMDV)O型Mya98谱系猪源和牛源毒株的序列差异,采用RT-PCR方法,对FMDV O型Mya98谱系牛源毒株(O/BY/CHA/2010)和猪源毒株(O/GZ/CHA/2010)的基因组全序列进行了扩增和测序,并与O型其他牛源和猪源参考毒株的基因组进行了比较分析。结果显示,O/BY/CHA/2010毒株和O/GZ/CHA/2010毒株都属于SEA拓扑型的Mya98谱系毒株。O/BY/CHA/2010毒株和O/GZ/CHA/2010毒株与来自Mya98谱系的其他毒株的全基因的核苷酸同源性大于98.0%。除了VP4、2A和3BCD区,O/BY/CHA/2010毒株和O/GZ/CHA/2010毒株与Mya98谱系的其他毒株的其他基因区的同源性较低。与非SEA拓扑型毒株(UKG/7B/2007、Akesu/58和PanAsia谱系毒株)相比,在2A、P2和3CD区,具有较高的同源性,表明O/BY/CHA/2010和O/GZ/CHA/2010可能具有这些毒株的生长特性。进一步的序列分析表明,O/GZ/CHA/2010毒株在L蛋白第10位增加了1个亮氨酸,在S片段缺失70个核苷酸。试验结果为进一步分析氨基酸插入和核苷酸缺失对毒株致病性的影响奠定了基础。

In order to identify sequence difference of Mya-98 lineage of Southeast Asia（SEA） topotype of foot-and-mouth disease virus（FMDV） isolated from pigs and cattle,the full-length nucleotide sequences of FMDV O/BY/CHA/2010（from cattle） and O/GZ/CHA/2010 （from pigs） strain were determined and compared with O/HKN/20/2010 and the other known FMDV strains. The homology analysis indicated that O/BY/CHA/2010 and O/GZ/CHA/2010 had 〉98% of nucleotide identity with the epidemic strains of O/HKN/20/2010 and O/VN/2009. However, except VP4,2A, and 3BCD regions, O/BY/CHA/2010 and O/GZ/CHA/2010 showed lower similarity in other gene regions with O/VN/2006 and HLJOC12/03 from SEA topotype. Except the strains of SEA topotype, UKG/7B/2007,Akesu/58 and the PanAsia strains had the highest identities in 2A, P2 ,and 3CD regions with O/BY/CHA/2010 and O/GZ/CHA/2010, suggesting that O/BY/CHA/2010 and O/GZ/CHA/2010 may have similar growth characteristics. In addition, the de-letion of L, 8A regions and 5＇-untranslated region（5＇UTR） were analyzed, and the results showed that there was an one-amino acid insertion for O/GZ/CHA/2010 and an one-amino acid deletion for O/BY/ CHA/2010 in the L^pro gene. Furthermore,comparison with these sequences revealed a deletion of 70 nucleo-tides within the 5＇-UTR for the O/GZ/CHA/2010 isolate which maintained a shorter RNA stem-loop that has been predicted for the S-fragment. Similar deletions were also observed in another five related samples collected during 2010 of isolates of Mya98 The results provide important information on comprehensive genetic characterization neage.