Development and Application of Duplex Real-time RT-PCR Assay for Detection of H1 and H3 Subtype Swine Influenza Viruses

To establish a rapid, accurate method to diagnose and detect H1 and H3 subtype swine influenza viruses (SIV) at the same time, the specific primers and TaqMan probes were designed according to the conserved region of the HA gene of H1 and H3 subtype SIV. A duplex Real-time RT-PCR assay was developed for detection of H1 and H3 subtype SIV. The results showed that the Real-time RT-PCR could detect 10² copies/μL of H1 and H3 subtype SIV, the sensibility was well. Coefficient of variation of Ct value between repeating groups were all below 5%, the repeatability was favorable. The results were negative for the detection of H4, H5, H7, H9 subtypes SIV, classical swine fever virus, porcine reproductive and respiratory syndrome virus, foot and disease virus and pseudorabies virus, the specificity was fine. One sample was H1 subtype SIV, and one sample was H3 subtype SIV, by the established assay, the positive rate was 1.16%. The method was highly accurate, rapid, sensitive and specific, and could provide a method for rapid detection and epidemiological investigation of H1 and H3 subtype SIV.     

荧光定量PCR检测牛性别相关基因DAX1表达的标准质粒和标准曲线的构建

本研究根据GenBank中登录的剂量敏感的性别反转－先天性肾上腺发育不良基因1(dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1,DAX1)设计引物,构建包含DAX1基因cDNA片段的质粒,作为中国荷斯坦牛DAX1基因mRNA定量检测的标准品,建立了DAX1基因mRNA表达实时荧光定量PCR检测方法。结果表明,该方法特异性好,检测灵敏度达102拷贝,线性范围为102～106拷贝,阈值循环数(Ct)与PCR体系中起始模板量的对数值间有着良好的线性关系(r=0.99975),扩增效率高(E=100%),可以作为检测牛DAX1基因mRNA定量检测方法。     

番茄褐色皱果病毒TaqMan 荧光定量RT-PCR检测方法的建立及应用

为建立番茄褐色皱果病毒(tomato brown rugose fruit virus, ToBRFV)TaqMan荧光定量RT-PCR方法,本研究针对ToBRFV RNA依赖的RNA聚合酶(RNA-dependent RNA polymerase, RdRP)基因序列设计了4组特异性引物和TaqMan探针,构建了标准曲线,并对该方法的特异性、灵敏度和实际样品的检测效率进行评估。结果显示,该方法特异性强,与番茄花叶病毒、番茄斑驳花叶病毒、烟草花叶病毒、黄瓜绿斑驳花叶病毒、番茄环斑病毒、番茄黑环病毒、辣椒轻斑驳病毒、烟草环斑病毒和凤果花叶病毒等9种病毒均无交叉反应。建立的标准曲线的R²为0.999,扩增效率为102.096%,检测灵敏度为10 fg/μL,与EPPO PM 7/146(1)推荐的CaTa28、CSP1325方法相当,是常规RT-PCR的100倍;采用该方法成功从60份番茄和辣椒叶片、种子样品中检出10份阳性样品。建立的TaqMan荧光定量RT-PCR方法特异性强、灵敏度高,适用于实际样品中ToBRFV的快速精准检测。     

五倍子蜂蜜TaqMan探针实时荧光定量PCR检测方法的建立

为五倍子蜂蜜的鉴定检测提供技术支撑,利用TaqMan探针实时荧光定量PCR技术,以五倍子树基因组中ITS基因为靶序列,设计并筛选出特异性引物探针,通过特异性、灵敏度和重复性等试验,建立五倍子蜂蜜TaqMan探针实时荧光PCR检测方法。结果表明:建立的方法特异性良好,生成的标准曲线有良好的线性关系,相关系数(R2)为0.998,最低检测限为0.2pg DNA/反应。该方法特异性强、灵敏度高、结果可靠。     

TaqMan荧光定量PCR检测鸡产蛋下降综合征病毒方法的建立及应用

根据GenBank公布的鸡产蛋下降综合征病毒六邻体蛋白基因的高度保守序列,设计了2对特异性引物和1条TaqMan探针.以构建的阳性重组质粒为标准品,绘制标准曲线,建立了一种快速检测鸡产蛋下降综合征病毒的TaqMan荧光实时定量PCR方法.该方法最小检出量达10 copies·μL-1,在1.0×102～1.0×108copies· μL-1检测范围间有良好的线性关系,特异性、稳定性和重复性也较好.用建立的本方法检测感染鸡产蛋下降综合征病毒鸡群的产蛋分离物,与普通PCR相比,该荧光实时定量PCR方法具有更高的敏感性,可更好地用于鸡产蛋下降综合征病毒的临床检测.     

应用DNA指纹图谱法对湘白猪群体遗传结构的研究

本文采用Ｊｅｆｆｒｅｙｓ小卫星探针３３．６和３３．１５检测了４个湘白猪品系（Ⅰ，Ⅱ，Ⅲ，Ⅳ）和５个亲本品种（大约克、长白、杜洛克、大围子、沙子岭）的ＤＮＡ指纹图谱。根据指纹带型计算了每个群体的相似系数、平均等位基因频率和最低杂合率。４个湘白猪品系的分析结果表明：湘白猪各品系内的相似系数为０．４５－０．４９，接近于欧美引进品种长白猪（０．４８－０．５０），具有较好的遗传纯合性。根据９个品种（系）的群     

EHP、SHIV双重TaqMan实时荧光定量PCR检测方法的构建及应用

本研究根据GenBank中已有的虾肝肠胞虫(EHP)和虾血细胞虹彩病毒(SHIV)基因的保守序列,设计特异的引物和探针。建立了快速诊断EHP和SHIV的双重TaqMan实时荧光定量PCR检测方法,并对其特异性、敏感性和稳定性进行检测。结果表明：该方法检测限可达10 copies/μL,其敏感性是SYBR Green real-time PCR的10倍,普通PCR法的100倍;对白斑综合征病毒、传染性皮下及造血组织坏死病毒、高致病性副溶血弧菌,以及桃拉综合征病毒的检测结果均为阴性,表明无交叉反应,具有良好特异性;重复性试验结果表明,该方法Ct值的变异系数小于4%,具有良好的稳定性。对37份已知检测结果的样品进行检测,结果符合率为100%。本研究建立的EHP和SHIV检测方法具有快速、特异性强、灵敏度高等优点,适用于对虾隐性感染的早期监测。     

猪圆环病毒2型TaqMan荧光定量PCR检测方法的建立

采用PCR方法克隆了猪圆环病毒2型 (porcine circovirus 2,PCV2) 衣壳蛋白（capsid protein,CAP）基因,构建了重组质粒p-18T-CAP,并将其作为标准阳性模板。参照GenBank收录的PCV2 ORF2基因设计合成1对特异性的引物和与该引物相匹配的特异探针,通过对反应条件进行优化,以定量的10倍系列稀释的质粒p-18T-CAP为标准品进行TaqMan荧光定量PCR扩增,建立了一种检测PCV2的TaqMan荧光定量PCR方法。试验结果显示,该方法与猪圆环病毒 1 型、猪流感病毒、猪繁殖与呼吸综合征病毒、猪伪狂犬病病毒、猪瘟病毒等均无交叉反应;该方法最低可检测到4.53×10²拷贝/μL,比PCR检测方法高100倍;其标准曲线线性范围是10²～10⁹拷贝/μL,且具有良好的重复性。     

A specific qualitative and real-time PCR detection of MON863 maize based on the 5′-transgene integration sequence

Genetically modified crops are widely grown in the world today. Labeling is required when genetically modified organisms (GMOs) are placed on the market. There is a need to establish a specific method for the detection of genetically modified foods. MON863 transgenic maize containing a Cry3Bb1 sequence that produces insecticidal protein cry3Bb1 is a major GMO crop. In this paper, we report studies that designed specific PCR primers and TaqMan probes based upon the 5′-transgene integration sequence, and developed qualitative and quantitative PCR conditions using these primers and probes. We determined the 5′-transgene integration sequence using a ligation-mediated polymerase chain reaction (LM PCR) method. In qualitative PCR studies, the limit of detection (LOD) was 0.5% for MON863 in 100 ng genomic DNA. In the quantitative PCR assays, the limit of detection (LOD) and limit of quantitation (LOQ) are 10 and 100 haploid copies, respectively. Maize samples with different contents of genetically modified component were tested using the established TaqMan real-time PCR system.     

3种根萤叶甲实时荧光PCR检测技术研究

根萤叶甲属(Diabrotica)被我国列为进境植物检疫性有害生物,该属中的玉米根萤叶甲(D.virgifera virgifera)、十一星根萤叶甲(D.undecimpunctata)、巴氏根萤叶甲(D.barberi)是北美的主要农业害虫。为了建立一种快速的分子鉴定方法以鉴定这3种根萤叶甲,本研究从田间采集的成虫样品中获得其部分mtDNA COI序列,与Gen Bank中的相关序列进行比对,设计筛选出3种根萤叶甲的特异性引物和TaqMan探针,并进行实时荧光PCR特异性和灵敏度检测。特异性检测结果表明,用目标种根萤叶甲DNA和其特异性探针和引物进行实时荧光PCR反应时,在30个循环反应内(Ct值30)有近S型扩增曲线出现,同时其他种均无荧光信号增长。此外,灵敏度结果显示,玉米根萤叶甲和巴氏根萤叶甲可检测的最小DNA模板浓度,即实时荧光PCR反应的灵敏度为0.1 ng/μL,十一星根萤叶甲为0.01 ng/μL。