新城疫病毒Lasota株F基因的克隆和序列分析

Cloning and Sequence Analysis of F Gene of Newcastle Disease Virus Lasota Strain

本试验采用RT-PCR方法对NDVLasota株的全长F基因进行了扩增与克隆,并对其进行测序。扩出的F基因核苷酸长度为1664bp,单一的开放阅读框编码553个氨基酸的长肽,序列中有6个糖基化位点,13个半胱氨酸残基,包括完整的F1片段和完整的F2片段。裂解位点区(112-117aa)氨基酸序列为Gly-Arg-Gln-Gly-Arg-Leu,与所有弱毒株在这一区域的序列(Gy-Arg/Lys-Gln-Gly/Ser-Arg-Leu)相符。同源性分析表明,Lasota株F基因与已发表的其它NDVF基因相比,核苷酸序列同源性在88%～99%之间,推导的氨基酸序列同源性在90%～99%之间。

The whole sequence of F gene of NDV Lasota strain was amplified by RT-PCR and sequenced after being directly inserted into the pGEM-T easy vector.The results indicated that F gene is 1664bp in length and has a single opening read frame,which encodes a polypeptide of 553 amino acids.In the amino acid sequence,there are 6 glycosylation sites and 13 cysteine residues.It contains entire F1 fragment and entire F2 fragment of F gene.The amino acid sequence of cleavage site region(residues 112～117) is Gly-Arg-Gln-Gly-Arg-Leu matching to that of all avirulent NDV strains(Gly-Arg/Lys-Gln-Gly/Ser-Arg-Leu).Comparison of F gene of NDV Lasota strain with F gene of other known NDV strains showed 89%～99% homology for nucleotide, and 90%～99% homology for amino acid,respectively.