Cloning And Sequence Analysis Of Genome Of Classical Swine Fever Virus Epidemic In Guangxi

According to the published nucleotide sequences of genome of classical swine fever virus(CSFV) strains shimen, HCLV and Paderborn, 11 pairs of specific primers were designed and synthesized, Eleven fragments had been successfully amplified from CSFV GXWZ02 strain by RT-PCR. These amplified fragments were cloned into pGEM-T or PMD18-T and sequenced. Assembly of sequences of the 11 fragments into a contiguous sequence was done using Vector NTI Suite 6 software, the 12296 nucleotide sequence was comfirmed in genome of GXWZ02 strain. Comparison of the genomic nucleotide sequence and the deduced amino acid sequence of GXWZ02 with that of Shimen, HCLV, 39, Brescia, Eystrup, Glentorf, Alfort187, Paderborn, CS, ALD, GPE", P97and LPC, showed that the nucleotide homologies were 85.4%, 84.6%, 88.7%, 85.7%, 85.7%, 85.3%, 85.6%, 95.3%, 85.7%, 85.7%, 85.4%, 83.4% and 84.3%, respectively, the amino acid sequence homologies were 92.6%, 91.7%, 94.2%, 93.1%, 92.9%, 92.3%, 93.0%, 97.7%, 92.6%, 93.0%, 92.6%, 90.5% and 90.6%, respectively. The homologies of genomic nucleotide sequence and deduced amino acid sequence of CSFV GXWZ02 with that of Shimen, HCLV were low,indicating that GXWZ02 was not only genetically different from Shimen and HCLV but antigenically also. Phylogenetic tree analysis based on the genomic nucleotide sequence showed that the 14 CSFV stains were divided into two groups. GXWZ02, Paderborn and 39 were classified into group 1 , and other strains were classified into group II. And the genetic relationship is very close between GXWZ02 and Paderborn. Comparison of the nucleotide sequences and the deduced amino acid sequences of different gene of GXWZ02 with that of Shimen, HCLV, demonstrated that the rate of genetic variation of NS5A, E2, NS2 and Erns genes was high, while that of NS3, NS4A and NS4B genes was low.