利用Red重组系统敲除大肠杆菌菌株ClpP基因方法的研究

为了研究ClpP基因的功能,试验利用Red系统的重组功能,通过PCR扩增出两端与大肠杆菌菌株ClpP基因上、下游序列同源,中间为氯霉素抗性基因cat的DNA片段,电击转化含质粒pKD46的大肠杆菌菌株DH091,筛选替换ClpP基因的阳性转化子,再导入质粒pCP20去除氯霉素抗性基因。结果表明:成功敲除大肠杆菌菌株ClpP基因。     

禽流感病毒分离株A/Goose/Guangdong/1/96(H5N1)全基因克隆及序列分析

本研究用无特定病原体（ＳＰＦ）鸡胚增殖禽流感病毒鹅体分离株Ａ／Ｇｏｏｓｅ／Ｇｕａｎｇｄｏｎｇ／１／９６（Ｈ５Ｎ１）（ＧＤ１／９６）,提取病毒基因组总ＲＮＡ,运用反转录－聚合酶链反应（ＲＴ－ＰＣＲ）技术分别扩增该病毒分离株的８个基因片段的ｃＤＮＡ,分别克隆后进行序列测定。序列分析结果表明,所扩增到的８个片段均包含相应的病毒基因的完整开放阅读框架。ＧＤ１／９６株与１９９７年香港禽流感事件中的４株香港流感病毒分离株（分别来自人、鸡、鸭和鹅）的ＨＡ基因的高度同源性说明它们可能起源于同一种系,但ＮＳ基因的差异说明它们分属于不同的基因群系。ＧＤ１／９６株与香港流感病毒分离株的核苷酸和推导的氨基酸序列的同源性较低（６３．９％￣９８．１％）,而香港流感病毒分离株之间的核苷酸和氨基酸序列的同源性很高（９６．５％￣１００％）,且香     

Construction of Antibacterial Peptide CecropinB Eukaryotic Recombinant Vector and Its Expression in Dairy Goat Mammary Gland Epithelial Cells

To investigate the expression of antibacterial peptide CecropinB cDNA in dairy goat mammary gland epithelial cells,the CecropinB gene was cloned and was inserted into a eukaryotic vector pECFP-C1 to construct the recombinant plasmid pECFP-B by genetic engineering technique.Recombinant plasmid pECFP-B was transfected into dairy goat mammary gland epithelial to detect the bactericidal activity of CecropinB.The expression of CecropinB was also detected.The result of RT-PCR demonstrated CecropinB gene was expressed in transfected cells.CecropinB recombinant plasmid DNA was injected into udders and CecropinB was expressed in mammary gland,exhibiting bactericidal activity to Staphylococcus aureus in vivo experiments.