Molecular Analaysis Of The Entire Gene Of An Avian Influenza Virus Isolates A/chicken/xinjiang/1/96(h14n5)

Avian influenza is an infection and / or disease syndrome caused by any subtype of influenza A virus, a number of the Orthomyxoviridae family. Influenza A viruses are responsible for major disease problem in bird, as well as in humans and lower mammals. Literally thousands of viruses, belong to many different antigen subtypes based on hemagglutinin(HA) and neumarninidae(NA) surface antigens, have been recovered from domestic and wild avian species throughout the world. Infection among domestic or canfined birds have been associated with a variety of disease syndromes ranging from subclinical to mild upper respiratory disease, loss of egg production to acute generalized fatal disease. Influenza A viruses are divided into subtypes according to the antigen nature of the HA and NA. So far there are 15 HA subtype and 9 NA subtype. A H14N5 subtype avian A influenza virus was isolated from Chicken in Shihezi of Xinjiang. The virus was named A/Chicken/Xinjiang/1/96 (H14N5) (CXJ1/96). There are three H14 subtype strains which were reported in the world. In this paper, in order to demonstrate the phylogenetic relationships between the CXJ1/96 strain and other isolates in China, we developed the research of the entire sequence analysis of the avian influenza virus CXJ1/96. The CXJ1/96 virus was propagated in specific pathogen free chicken embryo. The viral RNA and mRNA were extracted and used reverse transcription olymerase chain reaction to amplify the ten full ength eDNA of the virus genes. The eDNAs were cloned into Srna I site of pUCll9 or pMDl8 vector and sequenced. The results showed that each of the ten genes eDNA fragment contained the whole open reading frame of each gene. The high homology existed among the nucleoproteins (NPs) of CXJ1/96 and other 7 influenza viruses isolated from chicken, duck and goose in China(96.6%9.0%), and the similar results came to the polymerase (PA, PB1 and PB2) (PA: 95. 5%7. 3%, PB1: 97. 3%8. 8%, PB2: 96. 5%8. 6%)but their nucleotide sequences homology were lower compared with amino acid sequences homology. However, very low homology associated with the non tructural (NS) proteins between CXJ1/96 and 4 avian influenza viruses in other 7 isolates showed that there were two different genetic groups in our country. The homology didnt exceed 71. 6%(61. 7%l. 6%) of entire NS gene between the two groups. There was only 8 or amino acid different in haemagglutinin between CXJ1/96 and the Gureiv isolates. Jo addition, insertion of 12 nucleotide (or four amino acid) occurred within NA molecular of CXJ1/96 strain compared with the only N5 subtype NA gene sequence in the Genebank. In order to demonstrate phylogenetic relationships between CXJ1/96 and other isolates in the world. Phylogenetic relationship tree were drew by Clustal V method in DNAstar with the isolates in motherland and HongKong of China, nucleotide and amino acid sequence identities of NS gene were separated into two group, NS of isolates CXJ1/96 is closely related to CK1/94, CFJ19/00 and those isolates from Hong Kong. Phylogenetic trees of other internal genes of human influenza viruses in Hong Kong were composed a minor clades, the other virus strains helong to different elades relatively. Additionally, variability dendrogram position suggested that reassortment among viruses contributed to the genetic variability of these viruses between HongKong influenza viruses and the isolates from mainland.