菊芋块茎发育期凝集素基因的鉴定和表达分析

凝集素是生物中普遍存在的一类糖结合蛋白,通过特异识别不同糖基而介导多种生物过程.本研究以'南菊芋1号'为研究材料,克隆并鉴定了12个凝集素基因.利用生物信息学分析这些基因编码蛋白的性质表明:等电点为4.96～5.23,偏酸性;依据其特异性糖基结合域归为三类:8个属于木菠萝家族(JRL),2个属于雪花莲家族(GNA),2...     

大豆凝集素的分子结构及其抗营养作用研究进展

概述了大豆凝集素的研究情况,总结归纳了大豆凝集素的分子结构、理化特性及其对动物和人类造成的抗营养作用。     

GNA和ACA双价转基因烟草培育及其抗蚜研究

蚜虫是一种常见的农作物害虫,作为多种植物病毒的载体而成为影响农业发展的重要害虫之一,对蚜虫的防治一直是众多科学工作者所面对的难题。构建了雪花莲凝集素(GNA)和苋菜凝集素(ACA)双价植物表达载体pBI121-GA,在农杆菌介导下,叶盘法转化烟草NC89,得到卡那霉素抗性植株65株。通过基因组PCR、ELISA、RT-PCR和Western-blot等分子生物学检测,从中筛选出外源凝集素不同表达水平的转基因烟草5株。对筛选出的5株转基因烟草植株进行初步蚜虫抗性实验,证实转基因烟草对桃蚜表现出一定的抗性,最高抑制率达85.8%,为农作物双价抗蚜基因的应用研究提供一定的理论基础。     

掌叶半夏凝集素基因表达载体的构建与鉴定

从掌叶半夏(Pinellia pedatisecta Schott)块茎中提取总RNA,反转录合成cDNA.根据GenBank中已报道的天南星科凝集素基因序列,设计带有酶切位点的表达引物,用RT-PCR方法扩增出掌叶半夏凝集素(Pinellia pedatisecta agglutinin,PPA)基因.PPA经双酶切后与表达载体pGEX-6P-3连接,构建pGEX-PPA重组表达载体.通过PCR、双酶切及测序鉴定,结果表明,重组载体pGEX-PPA构建成功,为进一步进行PPA的原核表达及其功能研究奠定了基础.     

大豆凝集素和脂肪氧化酶双价RNAi表达载体的构建及其遗传转化

【目的】应用RNA干扰技术,同时抑制大豆凝集素(Soybean agglutinin,SBA)和脂肪氧化酶(Lipoxygenase,Lox)基因在种子中的表达,改良大豆营养品质,为培育优质大豆材料奠定基础。【方法】根据RNAi原理,酶切获得Lox目的片段,构建以除草剂Bar基因为筛选标记、种子特异性启动子P7αP启动SBA和Lox双干扰的pCAMBIA3301-SBA-Lox(pSBA-Lox)干扰表达载体,并通过农杆菌介导法转化大豆(品种为吉农28),采用PCR、Southern杂交和实时荧光定量PCR对转基因植株进行检测。【结果】质粒PCR和酶切鉴定结果表明,双价RNAi植物表达载体pSBA-Lox构建成功。将其转入到大豆中,对转化植株进行PCR、Southern杂交检测,结果显示,外源基因以单拷贝形式整合到植物基因组中,并能遗传给后代。T1代转基因植株的实时荧光定量PCR分析显示,转基因植株中SBA基因和Lox基因在籽粒中的表达量比未转化受体植株均明显降低,SBA基因表达量降低了35.9%~47.2%,Lox基因表达量降低了32.8%~56.1%,而在幼嫩叶片中的表达量相比对照植株变化不大。【结论】获得了大豆凝集素和脂肪氧化酶表达量均明显降低的T1代转基因大豆。     

The wheat germ agglutinin binding sites and development of the mitochondria-rich cells in gills of tilapia (Oreochromis mossambicus)

By labelling with gold-colloid-conjugated wheat germ agglutinin (WGA), the WGA-binding sites were identified in the apical region of certain mitochondria-rich (MR) cells in gills of freshwater-adapted tilapia (Oreochromis mossambicus). Bromo-deoxyuridine (BrdU) injection was used to discern the differentiation of the WGA binding sites during development of MR cells. Double labeling of gill sections of fish 2, 4, 6, and 8 days after a single BrdU injection showed that the BrdU labeled MR cells 2 and 4 days after injection were mostly WGA negative, whereas 6 and 8 days after injection, WGA and BrdU-labeled MR cell increased gradually in number. Furthermore, the ratio of the WGA-positive to total MR-cells was higher in gills of tilapia adapted to low calcium ([Ca] = 0.015 mm) freshwater than in hard freshwater ([Ca] = 1.898 mm). The results indicate that WGA binding site may be a marker expressed late during differentiation of MR cells, and physiologically functional in assisting uptake of calcium when environmental calcium is low. According to their WGA binding and also characteristics their likely function in calcium absorption, the WGA positive MR cells shown in this study are considered to be similar to the cells described by Pisam et al. (1995).     

Variations in Seroprevalence and Host Factors for Bovine Anaplasmosis in Illinois

Hungerford, L.L. and Smith, R.D., 1997. Variations in seroprevalence and host factors for bovine anaplasmosis in Illinois. Veterinary Research Communications, 21 (1), 9-18.The modified card agglutination test (MCAT) was used to detect antibodies to Anaplasma marginale in 4994 samples collected from market cattle through the Brucellosis Eradication Program in Illinois. The MCAT reactor rate in the sample was 6.4%. The statewide prevalence estimate increased to between 7.1% and 10.7% when corrected for sampling distribution and test sensitivity and specificity. While the sample reactor rate measures the proportion of infected cattle moving through the market system and into new herds, consideration of the sampling proportions and test characteristics is important when estimating the overall prevalence. Cows were found to be at decreased risk relative to male cattle in lower-prevalence areas, but the risk was similar in higher-prevalence areas. In both higher- and lower-prevalence areas, the risk for seropositivity increased from 1 year of age onwards, but the rate of increase with age was greater in the higher-prevalence areas. Calves, however, had higher seroprevalence levels than 1-2-year-old animals. The risk was highest for Angus and Angus-Hereford cross cattle, while dairy cattle showed a decreased risk in the whole sample, but not when the analyses were stratified by prevalence level. There was a higher concentration of dairy cattle in areas with lower prevalence levels.     

牛精子膜麦芽凝集素结合糖蛋白的分离与定位

牛精子膜用非离子去污剂 NP-40增溶,经固相凝集素亲和层析,初步分离了精子膜麦芽凝集素结合糖蛋白,经 SDS-聚丙烯酰胺凝胶电泳、银染色显示出了四条蛋白质带,分子量分别为78,60.42和33 kD。用分离到的糖蛋白制备抗血清,对牛精子进行免疫细胞化学标记,结果顶体区显示为强阳性,与麦芽凝集素亲和细胞化学的染色一致。用抗血清处理精子再进行亲和细胞化学染色时,顶体区的麦芽凝集素结合糖残基多数被封闭,揭示麦芽凝集素结合糖残基是构成抗原决定簇的成分。     

白肋烟转基因育种研究

利用农杆菌介导法将具有广谱抗病的葡萄糖氧化酶(Glucose Oxidase,GO)基因及抗虫半夏凝集素(Pinella Ternata Agglutinin,PTA)基因转化到烟草中,并研究了影响转化和抗性植株再生的一些因素。结果表明,基因型是影响转化和抗性植株再生的关键因素,试验所用的3个品种KY14、KY8959、TN90中,KY14转化效率最高。用于烟草转化的侵染时间以15min为宜,共培养时间以2d最佳。PCR分子检测表明,外源GO基因及PTA基因已转入到烟草KY14中。淀粉-碘化钾显色反应检测到了转基因植株产生的过氧化氢,证实GO基因已经在烟草中发挥功能。     

Study on the Obtaining of Transgenic Wheat with GNA Alien Gene by Biolistic Particle

The immature embryos of wheat plants, cv. Jing 411, 12 - 14 days after pollination, were cultured on SD2 medium for callus induction. After 10 days culture, 800 wheat calli were bombarded by biolistic particle coated with theDNA of plasmid pBI121-2 harboring both Galanthus nivalis agglutinin gene and bar gene. 67 green plants were finally regenerated from the bombardment calli on selection medium containing 4mg/L Basta. The results of bioassay by both inoculating wheat aphids onto the plants and applying Basta solution of 50 mg/L and 75 mg/L onto the wheat leaves in the field, and the molecular analysis, such as PCR and Southern blotting, indicated that 8 T2 plants contaning the target genes were obtained.