猪瘟病毒RT-PCR产物的T载体克隆、测序及同源比较

MOLECULAR CLONING BY pUC 18 T VECTOR AND NUCLEOTIDE SEQUENCE OF THE RT PCR PRODUCT OF CLASSICAL SWINE FEVER VIRUS

利用ＴａｑＤＮＡ聚合酶的无模板延伸活性制备了可直接克隆ＰＣＲ产物的Ｔ载体，并成功地对猪瘟病毒ＨＣＬＶ株的ＲＴ－ＰＣＲ产物进行了克隆．ＤＮＡ序列测定和同源性分析表明该ＲＴ－ＰＣＲ产物是猪瘟病毒特异的，与已知序列的猪瘟病毒毒株的序列同源性均高达９６．７％～９８．７％．ＨＣＬＶ株与Ｃ株具有相同的起源，但序列比较发现它们既有共同的点突变，也有序列上的差异，表明这两株病毒在各自独立的传代过程中已发生了各不相同的遗传性变异，值得进一步比较研究．

A kind of pUC18 T Vector modified to pUC 18 DNA/Sma I fragment by Taq DNA polymerase was developed, to which the RT PCR product of Classical Swine Fever Virus (CSFV) was cloned successfully. DNA sequencing and homologous analysis indicated that the RT PCR product was CSFV specific, which was homologous to the counterpart sequences published of the 5 strains of CSFV by 96.7% to 98.7%, respectively. Although CSFV strain HCLV and strain C were derived from the same parental virus, nucleotide sequence comparision revealed that they have common point mutation as well as different base changes, which indicated that different genetic variation had been introduced to the 2 strains of CSFV during their seperate passaging period.