【摘要】 对柔嫩艾美耳球虫(E.tenella)BJ 株 SO7基因进行了克隆和测序分析。以纯化的 E.tenella BJ 株7h 孢子化卵囊的总 RNA 为模板,应用 RNA 反转录酶(M-MLV)合成 cDNA,再用 Taq DNA 聚合酶进行PCR 扩增出 BJ 株 SO7基因.用常规基因克隆方法把 BJ 株 SO7基因插入 pGEM-T 克隆载体,选取正方向插入子的一个阳性克隆进行酶切分析及插入片段的全序列测序分析。结果表明:该序列全长862个核苷酸,有一个开放性读框(65～713nt),可编码216个氨基酸(22.4kD)。SO7-BJ 与国外株 SO7比较,同源性为99%,突变的8个核苷酸中,4个为有义突变.开放性读框中有仅2个核苷酸突变,其中1个为有义突变,使推测氨基酸 Cly 变为 Cys。更多还原

【Abstract】 SO7 gene of E.tenella BJ strain infecting chickens in Beijing was cloned and se- quenced.E.tenella RNA was extracted from sporulating oocysts and used as a template for cDNA synthesis after reverse transcription.SO7 cDNA was amplified by means of polymerase chain reaction(PCR).The PCR products were checked by agrose gel elec- trophoresis and then cloned into pGEM-T easy Plasmid vector successfully.The SO7-spe- cific cDNA recombinant plasmids were analysed with Restriction Endonucleases(RE) (EcoR Ⅰ,EcoR Ⅰ+Stu Ⅰ,Sin Ⅰ,Sac Ⅱ,Nae Ⅰ)digestion.Nucleotide sequence was de- termined by dideotide chain-termination method.The results indicated that SO7-BJ gene is 862 bp in lenghth and includes 5’-flanking region,opening read frame which code for a polypeptide of 216 amino acid(molecular weight 22 kD)and 3’-flanking region.Compari- son of SO7BJ with the published nucleotide sequence of SO7 demonstrates they have the sequence homologies of 99%.Comparing its dedueed amino acid sequence with reported amino acid sequence of SO7 demonstrated that they have homologies of 98.6%.更多还原