北京地区TT病毒分离株全基因的克隆及序列测定

目的 克隆和测定北京地区ＴＴ病毒（ＴＴＶ）分离株全基因序列。方法 采用聚合酶链反应（ＰＣＲ）技术从１例临床非甲￣庚型肝炎病人血清中分段扩增ＴＴＶ全基因，获得５个互相重叠的片段，分别长１９９ｂｐ（１－１９９），１２６７ｂｐ（９０－１３５６，８７８ｂｐ（１３５４－２２３１，１１２９ｂｐ（２１７８－３３０６，４３４ｂｐ（３３０６－３７３９），用标准的分子生物学方法测定了这５个序列，从而得到全长ＴＴＶ基因

Cloningand sequencing of complete TT virus genome from Beijing isolate of China

OBJECTIVE: To obtain the complete TT virus genome from a Beijing isolate of China. METHODS: PCR was performed for amplifying the TT virus genome from serum of a patient with non A-G hepatitis. Five overlapped fragments, that are 199 bp (1-199), 1 267 bp (90-1356), 878 bp (1354-2231),1129 bp(2178-3306),'434 bp(3306-3739), respectively, were obtained. These PCR products were sequenced by standard method. RESULTS: The complete TT virus genome of Beijing isolate consists of 3 739 nucleotides involving two ORFs. The first ORF locates at 589-2902 nt, encoding 770 amino acids, the second ORF locates at 107-715 nt, encoding 202 amino acids. 5' and 3' terminus of the genome are non-coding regions including 106 bp and 837 bp respectively. In this genome, A is 31.2%, C 25.4%, G 22.5% and T 20.9%. The homology of Beijing isolate and Japanese TT virus was more than 95% at both nucleotide and amino acid levels. CONCLUSIONS: We successfully cloned and sequenced the complete TT virus genome from a Chinese patient. This Beijing TT virus isolate and that reported by Japan all belong to a same genotype.