Cloning and sequence analysis of M and NS of H1N1 swine influenza virus.

Two pairs of primers were designed according to the M gene and NS gene sequences of H1N1subtype of swine influenza virus(SIV) published in GENEBANK.The M gene and NS gene of TJ2 and TJ4 strain were amplified by RT-PCR,and then were subcloned into pMD18-T vector and sequenced,respectively.The results showed the length of complete M gene was 1027 bp.The nucleotide homologies of the M genes between TJ2 and TJ4 strain and the reference strains were from 85.8 % to 99.7 %.The length of NS gene was 890 bp.The nucleotide homologies of the NS genes between the tested strains and the reference strains were from 80.7 % to 99.2 %.Phylogenic analysis based on M and NS gene showed TJ2 and TJ4 strain belonged to the same branch with SIV isolated from Guangdong,Shanghai and Hongkong,but the sequence distance was more close between tested strains and the SIV isolated from Guangdong and Shanghai than that of isolated from Hongkong.And sequence distance from TJ2 and TJ4 to reference strains of H1N1 subtype of human influenza virus and vaccine strain against SI from other countries were far more than others virus.