柔嫩艾美耳球虫(Eimeriatenella)HB株SO_7’基因的克隆和序列分析

Cloning and Sequencing of SO_7' Gene of Eimeria tenella

对柔嫩艾美耳球虫 (E .tenella)HB株SO7’基因进行了克隆和序列分析。以纯化的E .tenellaHB株孢子化卵囊的总RNA为模板 ,应用RT -PCR扩增出HB株SO7’基因。将HB株SO7’基因插入 pMD18-T载体 ,经PCR及酶切鉴定为阳性的克隆进行测序分析。结果表明 :该序列为一全长 6 5 1个核苷酸的开放阅读框 ,富含CAG和CTG重复序列 ,可编码 2 16个氨基酸。SO7’ -HB与国外株SO7’ -LS18比较 ,核苷酸序列同源性为 99.2 % ,开放性读框中有 5个核苷酸突变 ,其中 3个为有义突变 ,使推测氨基酸V变为A ,A变为V ,S变为G ,二者推测氨基酸序列同源性为 98.6 %。

SO_7' gene of E.tenella isolated from chickens in HeBei was cloned and sequenced. E.tenella RNA was extracted from sporulated oocysts and used as a template for cDNA synthesis. SO_7' cDNA was amplified by RT-PCR. The PCR products were cloned into pMD18-T vector successfully. The recombinant plasmids were analysed with restriction endonucleases and sequenced. The results indicated that SO_7'-HB gene was 651bp in length and included opening read frame which encoded a polypeptide of 216 amino acid. Comparing SO_7'-HB strain gene with the published sequence of SO_7'-LS18,the nucleotide sequence homology was 99.2%.And the homology of its deduced amino acid sequence was 98.6%.