| Taura syndrome virus (TSV) is one of the etiology agent causing acuate contagion of Penaeus vannami, which lead prawn infect with serious disease in China in recent years. So far in China, only a few isolates of TSV has been identified. To determine the prevalence of TSV infections in Chinese shrimps and the extent genetic variation among Chinese TSV isolates, we tested 310 samples collected from 31 shrimp farms at 7 different regions for the presence of TSV by RT-PCR. 166 (53.5%) of the 310 shrimps were positive for TSV. The positive rates among Penaeus vannami were 100%, 97.1%, 33.3%, 40.7%, 50% and 40% in Zhangzhou, Xiamen, Shenzhen, Yangjiang, Ningbo, Guangzhou respectively. Southern blot and nucleotide sequencing were performed to confirm the specificity of the amplified RT-PCR products. The homology of 231bp nucleotide sequences reached 98.7-100% when analysed and compared with the GenBank using the BLAST program. Phylogenetic analyses clustered the TSV isolates into two groups: one contained Unite States, Mexico, Belize, and Taiwan isolates; the other contained Vietnam isolate (YN1) and 21 isolates of mainland China. The 21 China isolates clustered into one branch, while the YN1 distributed in another branch. 5 strains from Guangzhou and 2 strains from Shenzhen constituted one subcluster of the China branch.Eight overlapping clones covering the whole viral genome of TSV ZHZC3 isolate were amplified by RT-PCR and the 5' and 3' ends were amplified with RACE. The PCR products were coned into pMD-18T vector and sequenced. The result showed that the genome of ZHZC3 consisted of 10202nt excluding the poly (A) tail, and contained two ORFs (ORF_s 1-2) which encoded polyproteins of 2107aa and 1011aa. No insertion or deletion was detected in the coding regions while 3nt of A were deleted at 5' UTR when compared with HI94. The overall nucleotide sequence identity between ZHZC3 and HI94...
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