棉铃虫激活增强子结合蛋白AP-4基因的原核表达、多克隆抗体制备、表达谱分析及功能鉴定

【目的】激活增强子结合蛋白4(activating enhancer binding protein 4, AP-4)是近年来备受关注的一类功能广泛的转录因子,参与Wnt/β-catenin信号通路的调控。本研究旨在研究棉铃虫Helicoverpa armigera HaAP-4基因的原核表达并制备多克隆抗体,明确HaAP-4基因的时空表达谱,初步探究HaAP-4对棉铃虫胆固醇载体蛋白2(sterol carrier protein-2, SCP-2)基因(HaSCP-2)表达的调控作用。【方法】通过PCR扩增棉铃虫HaAP-4基因片段,将其克隆至pET-28a原核表达载体,转化至大肠杆菌Escherichia coli BL21,经IPTG诱导表达,采用镍柱纯化重组蛋白,免疫新西兰兔制备多克隆抗体。运用RT-qPCR检测HaAP-4基因在棉铃虫不同发育阶段(卵、幼虫、预蛹、蛹和成虫)以及5龄幼虫和预蛹不同组织(中肠、脂肪体、头和表皮)中的表达水平。设计并合成HaAP-4 siRNA,转染棉铃虫Ha细胞,通过RT-qPCR检测和分析使用HaAP-4 siRNA进行RNA干扰后Ha细胞中HaAP-4和HaSCP-2基因 mRNA的表达情况。【结果】成功构建pET-28a-HaAP-4重组表达质粒,在大肠杆菌细胞中获得高效表达的可溶性蛋白,目的蛋白大小约为55 kD,经纯化获得了纯度较高的重组蛋白,免疫新西兰兔成功制备了多克隆抗体,通过Western blotting检测显示抗体具有较好的特异性,ELISA分析表明抗体效价较高。发育阶段特异性表达结果显示,HaAP-4基因在棉铃虫不同发育阶段均有表达,其中在卵期、5龄幼虫期和预蛹期的表达量较高。组织表达结果表明,HaAP-4基因在5龄幼虫和预蛹不同组织中均有表达,且在中肠和头部具有高表达,而在表皮和脂肪体中表达量较低。RNA干扰实验发现,HaAP-4基因的敲降对HaSCP-2基因转录有显著影响,HaSCP-2基因mRNA表达水平下降了约55%。【结论】利用pET-28a原核表达系统能有效地在体外表达可溶性的HaAP-4,并制备了较好的多克隆抗体。RNAi实验结果提示,在中肠内高表达的HaAP-4基因能促进HaSCP-2基因的转录表达,在棉铃虫脂质生理代谢过程中发挥作用。本研究为进一步深入阐明棉铃虫HaAP-4的潜在功能打下了基础。     

棉铃虫转录因子c-Myc基因在滞育和非滞育蛹脑中的表达分析及多克隆抗体制备

【目的】c-Myc是近年来研究较多的转录因子,也是受Wnt/β-catenin信号通路调节的重要靶标。本研究旨在克隆棉铃虫 Helicoverpa armigera c-Myc基因,从核酸水平初步调查 c-myc 在滞育和非滞育蛹脑中的表达情况,同时制备其蛋白的多克隆抗体。【方法】通过RACE方法克隆棉铃虫 c-myc 基因的cDNA,运用RT-PCR方法比较滞育和非滞育蛹脑中Har-c-myc基因的表达情况。根据获取的序列构建原核表达载体,在大肠杆菌 Escherichia coli 中进行表达,纯化后免疫新西兰兔,制备了多克隆抗体。【结果】克隆了棉铃虫 c-myc 基因,核酸水平的研究表明滞育蛹脑中 c-myc 表达水平明显低于非滞育蛹脑。成功地在大肠杆菌中表达了c-Myc部分肽段并通过镍柱纯化获得了较纯的重组蛋白。制备的c-Myc抗体效价达到了1:125 000。【结论】滞育蛹脑中 Har-c-myc 的表达下调。获得了抗棉铃虫c-Myc的多克隆抗体。本研究的成果为后续进一步深入研究棉铃虫Wnt/β-catenin信号通路在棉铃虫发育中的作用奠定了基础。     

人生长分化因子15的原核表达、纯化与多克隆抗体制备

目的:原核表达并纯化、鉴定人生长分化因子15(GDF-15),制备其多克隆抗体。方法:从人结肠癌细胞系HT29的cDNA扩增出GDF-15基因片段并插入pET-32a(+)原核表达载体,转化大肠杆菌BL21,IPTG诱导表达重组GDF-15,用镍亲和柱纯化,SDS-PAGE、Western印迹鉴定重组蛋白。用纯化的重组GDF-15免疫BALB/c小鼠制备多克隆抗体,鉴定并检测其效价。结果:制备了pET-32a(+)-GDF-15表达载体;经IPTG诱导重组蛋白表达后,采用Ni亲和柱纯化蛋白,并经SDS-PAGE和免疫印迹鉴定;免疫BALB/c小鼠后获得了GDF-15多克隆抗体,ELISA检测抗体效价为1∶100000,并应用于肿瘤细胞的GDF-15检测中。结论:用基因工程和免疫学方法制备了重组人GDF-15及其多克隆抗体,为后续的分子机制和靶向治疗研究奠定了基础。     

棉铃虫钙粘蛋白N端多肽多克隆抗体制备及对Bt抗性的初步检测

用重组表达的棉铃虫Helicoverpa armigera(Hübner)中肠钙粘蛋白N端多肽片段制备兔多克隆抗体,并利用其对Bt抗性进行鉴定。通过RT-PCR方法对棉铃虫中肠钙粘蛋白N端多肽的基因片段Cad285进行PCR扩增,将其克隆到pET-30a原核表达载体中,在大肠杆菌BL21(DE3)中经IPTG诱导表达,得到35ku的重组融和蛋白,融合表达的包涵体经过变性、Ni-NTA柱亲和纯化、复性等方法处理包涵体,获得可溶性纯化蛋白,用纯化后蛋白免疫新西兰兔制备多克隆抗体,ELISA检测其效价高于1∶16000;利用最终获得的多克隆抗体对室内纯合Bt抗/感品系的棉铃虫中肠钙粘蛋白进行Western blot分析,结果显示敏感和抗性品系之间有明显差异,表明其能够应用对Bt抗性进行初步检测。     

轮状病毒VP7基因的克隆与表达

应用聚合酶链式反应技术(PCR)扩增轮状病毒VP7基因,并将其克隆到pMD18-T simple载体上,对重组子进行PCR检测和限制性内切酶分析,并测定DNA全序列。结果显示,克隆片段全长为981 bp。将轮状病毒VP7基因定向的克隆到原核表达载体pET-32a启动子下游,构建原核表达载体pET-32aVP7。将质粒pET-32aVP7转化Transetta表达菌株进行诱导表达,裂解菌体细胞抽提蛋白质进行SDS-PAGE。结果表明,轮状病毒壳蛋白VP7基因在Transetta表达菌株内得到成功表达。     

西方蜜蜂AmAGO1蛋白的分子特性、时空表达谱及抗体制备

【目的】Argonaute (AGO)家族是一类在进化上高度保守的蛋白家族,其在真核生物中主要参与形成RNA诱导沉默复合体(RNA-induced silencing complex, RISC),进而通过沉默基因表达参与诸多生物学过程。蜜蜂AGO蛋白的相关研究迄今仍然缺失。本研究拟通过预测西方蜜蜂Apis mellifera的AGO1(AmAGO1)理化性质和分子特性,解析AmAGO1在西方蜜蜂中的时空表达谱,并制备AmAGO1的多克隆抗体,为深入开展AmAGO1的功能与机制研究提供参考和基础。【方法】PCR扩增西方蜜蜂AmAGO1的编码序列(coding sequence, CDS);通过生物信息学预测AmAGO1蛋白的理化性质和分子特性;利用RT-qPCR检测AmAGO1在西方蜜蜂工蜂卵、3日龄幼虫、7日龄预蛹、8日龄预蛹、12日龄蛹以及1, 2, 6, 12, 15和18日龄成虫以及工蜂成虫触角、咽下腺、脑、表皮、中肠、脂肪体和毒腺中的表达量;构建原核表达质粒后诱导表达AmAGO1融合蛋白,并鉴定其表达形式;制备AmAGO1多克隆抗体,利用ELISA, Western blot...     

DC-SIGN胞外区基因的克隆、蛋白表达及抗体制备

旨在构建DC-SIGN胞外区基因原核表达质粒,诱导蛋白表达并制备多克隆抗体。用PCR的方法扩增编码DC-SIGN胞外区的基因序列,将其克隆到原核表达载体pET-28a(+)中,利用大肠杆菌表达系统表达DC-SIGN胞外区蛋白,用H is抗体做W estern Blotting鉴定目的蛋白的免疫原性。用纯化的DC-SIGN胞外区蛋白免疫日本大耳白兔,制备多克隆抗体。通过酶联免疫吸附试验(ELISA)检测抗体效价,免疫荧光法检测其特异性。结果显示,原核表达载体pET-28 a(+)-DC-SIGN胞外区基因成功构建,可在大肠杆菌BL21(DE3)中高效表达,获得相对分子质量约20 kD的DC-SIGN胞外区蛋白,经Westernb lotting鉴定为正确。纯化后的蛋白免疫大耳白兔,制备的多克隆抗体具有较强免疫原性和特异性。本研究得到了纯化的DC-SIGN胞外区蛋白,并制备了具有特异性和高效价的抗体,为研究DC-SIGN生物学功能提供试验基础。     

Tamdy病毒糖蛋白基因的重组表达及抗体制备

原核表达Tamdy病毒（Tamdy virus,TAMV）糖蛋白Gn和Gc,分别制备兔抗融合蛋白Gn和Gc多克隆抗体。利用RT-PCR扩增Gn和Gc基因片段,分别构建原核表达质粒pET-28a-Gn和pET-32a-Gc,并在E.coli BL21(DE3)中诱导表达,镍柱亲和层析纯化融合蛋白Gn和Gc之后,以皮下注射方式分别免疫新西兰兔,制备兔抗融合蛋白Gn和Gc多克隆抗体。经Western Blotting和间接免疫荧光（IFA）鉴定多克隆抗体抗原识别能力,ELISA法测定抗体效价。结果显示,pET-28a-Gn、pET-32a-Gc原核表达质粒构建正确,融合蛋白Gn和Gc大小分别约为45 kD、74 kD,制备的兔抗融合蛋白Gn和Gc多克隆抗体能够分别识别原核表达的融合蛋白Gn和Gc和真核表达产物,效价分别为1∶409 600、1∶204 800。制备的多克隆抗体效价高,能够特异性识别原核系统和真核系统表达的TAMV糖蛋白,为TAMV的流行学分析提供基础。     

棉铃虫核多角体病毒泛素基因的克隆表达及抗体制备

昆虫杆状病毒和痘病毒是目前已知唯一编码泛素基因的病毒.通过PCR方法,克隆了棉铃虫核多角体病毒(HaSNPV)泛素基因(Ubiquitin,Ubi).序列分析表明,该基因编码区全长252bp,编码83个氨基酸残基,预计分子量为9.24kDa.将泛素基因克隆到原核表达载体pET-28a上,构建重组质粒pET-Ubi,转化至大肠杆菌BL21(DE3)感受态细胞中,IPTG诱导表达融合蛋白.用His-tag抗体检测目的蛋白,Westen-blot实验证明所表达的蛋白是带有His-tag的重组融合蛋白.通过改变IPTG浓度和诱导时间对表达条件进行了优化.利用NI-琼脂糖凝胶亲和层析柱纯化目的蛋白,SDS-PAGE鉴定为单一条带,同时用提纯蛋白制备了特异性抗体,为进一步的研究打下基础.     

肠三叶因子在大肠杆菌中的表达、纯化及其抗体制备

目的:获得肠三叶因子(ITF)的原核表达产物及抗rITF抗体,为深入研究ITF的作用机制及其受体研究奠定基础。方法:常规提取人小肠组织总RNA,用RT-PCR获得ITF编码基因片段,克隆至质粒pET32a获得原核表达栽体,双酶切和测序后转化至Origami B(DE3)用IPTG诱导表达,优化条件获得最大表达产量;用SDS-PAGE、Western blot鉴定表达产物,亲和层析纯化获得的重组蛋白rITF皮下多点注射家兔,制备多克隆抗体,并用此抗体进行大鼠肠组织免疫组化研究。结果:测序证实PCR扩增获得ITF全长基因序列与基因文库中的完全一致,将该基因片段正确插入表达载体pET32a中、优化表达条件后,重组蛋白的表达量达到50mg/L;Western blot证明重组蛋白具有良好的抗原性和特异性;通过Ni-NTA亲和层析、超滤离心后,得到90%纯度的蛋白;收集兔血清,纯化后获得特异性良好的ITF抗体,免疫组化染色肠组织显示ITF表达的部位定位于杯状细胞。结论:成功构建了表达载体pET32a-ITF,在大肠杆菌中表达并纯化获得纯度较高的rITF,并获得了生物活性较高的ITF抗体,ITF主要在肠道杯状细胞分泌表达。     

Gene expression in Plasmodium: from gametocytes to sporozoites

Completion of the complex developmental program of Plasmodium in the mosquito is essential for parasite transmission, yet this part of its life cycle is still poorly understood. In recent years, considerable progress has been made in the identification and characterization of genes expressed during parasite development in the mosquito. This line of investigation was greatly facilitated by the availability of the genome sequence of several Plasmodium, and by the application of approaches such as proteomics, microarrays, gene disruption by homologous recombination (gene knockout) and by use of subtraction libraries. Here, we review what is presently known about genes expressed in gametocytes and during the Plasmodium life cycle in the mosquito.     

苏云金芽胞杆菌杀线虫伴胞晶体蛋白基因cry6Aa的克隆与表达

通过对晶体蛋白N-末端氨基酸测序,设计简并探针,从对根结线虫高毒力苏云金芽胞杆菌YBT-1518菌株中克隆到1个含有杀线虫晶体蛋白基因的片段。序列测定表明该序列含有两个ORF(orf1和orf2),其中orf1与基因cry6Aa1同源性为98%,已在GenBank上登录(Acc.NO.AF499736),并被命名为cry6Aa2。将克隆的该片段克隆到穿梭载体pHT304上,并转化苏云金芽胞杆菌无晶体突变株BMB171,重组菌株可形成米粒状伴胞晶体。生物测定表明,表达的毒素蛋白对北方根结线虫的LC₅₀为9.47μg/mL,毒力与出发菌株(10.74μg/mL)相当。     

Evolutionary relationships among aquatic anamorphs and teleomorphs: Lemonniera, Margaritispora, and Goniopila

The hypothesis that similar conidial morphologies in aquatic hyphomycetes are a result of convergent evolution was tested using molecular sequence data. Cladistic analyses were performed on partial sequences of 28S rDNA of seven species of Lemonniera, one species of Margaritispora and one species of Goniopila. Lemonniera has tetraradiate conidia with long arms, whereas Margaritispora and Goniopila have typically globose (isodiametric) conidia, with short conical protuberances in a stellate or quadrangular arrangement. Lemonniera and Margaritispora have phialidic conidiogenesis and both produce dark, minute sclerotia in culture whereas Goniopila has holoblastic conidiogenesis and does not produce sclerotia in culture. Goniopila produces a microconidial phialidic synanamorph in culture. All three genera have schizolytic conidial secession. Molecular analyses demonstrate that Lemonniera species are placed in two distinct clades: one within Leotiomycetes; the other within Pleosporales, Dothideomycetes. Margaritispora is placed with Lemonniera species within Leotiomycetes. Goniopila and Lemonniera pseudofloscula are placed within Dothideomycetes. No morphological character was entirely congruent with the molecular derived phylogeny. This suggests that for the group of species studied, conidial shape is not a reliable indicator of phylogeny but more likely the result of convergent evolution in response to the aquatic environment.     

鹅掌楸LcUGE基因的克隆和组织表达分析

为了解鹅掌楸(Liriodendron chinense)的UGE基因功能,采用RACE和EPIC-PCR技术克隆到2个UGE基因,命名为LcUGE1和LcUGE2。结果表明,LcUGE1基因的c DNA全长为1 531 bp,包含1 050 bp的开放阅读框,编码349个氨基酸, gDNA长度为11 920 bp;LcUGE2基因的c DNA长度为1 378 bp,包含1 056 bp的开放阅读框,编码351个氨基酸,g DNA长度为6544 bp。LcUGE1和LcUGE2基因均含有9个外显子和8个内含子,且外显子长度和内含子剪切位点序列几乎一致,但内含子片段长度存在显著差异。编码的LcUGE1和LcUGE2蛋白高度保守,保守性达到82%。LcUGE1基因在雄蕊中表达量最高,而LcUGE2基因则在花萼中表达量最高。这表明LcUGEs基因可能参与鹅掌楸的生殖发育过程。     

A new fungal genus, Teracosphaeria, with a phialophora-like anamorph (Sordariomycetes, Ascomycota)

The new genus and species Teracosphaeria petroica is described for a perithecial ascomycete and its anamorph occurring on decayed wood collected in New Zealand. The fungus produces immersed, non-stromatic ceratosphaeria-like perithecia in nature, with hyaline, septate ascospores produced in unitunicate, non-amyloid asci. The anamorph produced in vitro is phialophora-like with lightly pigmented phialides terminating in flaring, deep collarettes that are often noticeably brown with conspicuous periclinal thickening. Phylogenetic analysis of LSU rDNA sequence data indicates that this fungus is distinct from morphologically similar fungi classified in the Chaetosphaeriales, the Trichosphaeriales or the Magnaporthaceae. It forms a monophyletic group with recently described, chaetosphaeria-like ascomycetes, such as the pyrenomycete genus Mirannulata, and shows affinity with the anamorphic species Dictyochaeta cylindrospora. The usefulness of describing anamorph genera for morphologically reduced anamorphs, when anamorph characteristics are actually part of the holomorph diagnosis, is discussed. An apparently contradictory example of the so-called Cordana and Pseudobotrytis anamorphs of Porosphaerella spp. is also discussed.     

Characterisation of cell wall polysaccharides, arabinogalactans-proteins (AGPs) and phenolics of Cola nitida, Cola acuminata and Garcinia kola seeds

Many Cola plant species are endemic to West and Central Africa. Cola acuminata and Cola nitida are used as masticatory when fresh, while the dried nuts are used for beverages and pharmaceutical purposes in Europe and North America. Garcinia kola seeds, that serve as a substitute for the true kola nuts, are used in African traditional medicine for the treatment of various diseases, including colic, headache and liver cirrhosis. Seeds extracts of G. kola are also known for their anti-inflammatory, antimicrobial and antiviral properties. To gain information on the chemical properties of the kolas, we have isolated and analyzed cell wall polysaccharides, arabinogalactan-proteins and phenolic substances from the seeds of the three kola species. The sugar composition of cell wall material of C. acuminata, C. nitida and G. kola revealed that Gal (up to 30%), Ara, GalA and Glc as the predominant monosaccharides, representing approximately 90% by mol of the total hydrolysable sugar present in this material. In Ammonium oxalate cell wall fraction, GalA was found to be the major sugar present in all kola species. In the alkali-soluble fraction, there were significant differences in the level of Glc and Gal. The level of Glc was high in C. acuminata and C. nitida while the level of Gal and Xyl were high in C. nitida and G. cola. Isolation and quantification of arabinogalactan-proteins demonstrate that G. kola seeds contained four to eight times more of these proteoglycans than the seeds of the other two species. Finally, analysis of soluble phenolic substances shows that caffeine and catechin were largely represented in C. acumina and C. nitida seeds, with caffeine accounting for 50% of all soluble phenolics. These findings indicate that the three Kola seeds are highly enriched in pectins and proteoglycans and that C. acuminata and C. nitida can be used as a possible source of caffeine and catechin.     

Cloning and expression of the gene for neutral protease of Bacillus amyloliquefaciens in Bacillus subtilis

A Bacillus amyloliquefaciens neutral protease gene was cloned and expressed in Bacillus subtilis.The chromosomal DNA of B. amyloliquefaciens strain F was partially digested with restriction endonuclease Sau3AI, and 2 to 9 kb fragments isolated were ligated into the BamHI site of plasmid pUB110. Then, B. subtilis strain 1A289 was transformed with the hybrid plasmids by the method of protoplast transformation and kanamycin-resistant transformants were screened for the formation of large halo on a casein plate. A transformant that produced a large amount of an extracellular neutral protease harbored a plasmid, designated as pNP150, which contained a 1.7 kb insert.The secreted neutral protease of the transformant was found to be indistinguishable from that of DNA donor strain B. amyloliquefaciens by double immunodiffusion test and SDS-polyacrylamide gel electrophoresis.The amount of the neutral protease activity excreted into culture medium by the B. subtilis transformed with pNP150 was about 50-fold higher than that secreted by B. amyloliquefaciens. The production of the neutral protease in the transformant was partially repressed by addition of glucose to the medium.     

穿龙薯蓣DnSQS基因的克隆及表达分析

角鲨烯合成酶(SQS)是植物甾醇和萜类化合物合成的关键酶之一。为了揭示穿龙薯蓣SQS基因的功能,该研究以穿龙薯蓣cDNA为模板,采用PCR方法克隆DnSQS基因,并对得到的序列进行生物信息学分析。采用HPLC方法检测不同组织的薯蓣皂苷元含量,采用实时荧光定量PCR技术分析DnSQS基因在不同组织、激素诱导及非生物胁迫下的表达特征。结果表明：(1)成功克隆得到穿龙薯蓣2个基因DnSQS1与DnSQS2,二者分别编码409和433个氨基酸,但编码的蛋白二级结构均以α螺旋和无规则卷曲为主,都存在由α螺旋折叠形成的保守催化中心以及2个富含天冬氨酸的功能结构,都具有2个跨膜螺旋结构,并且都定位于内质网。(2)DnSQS1和DnSQS2与盾叶薯蓣DzSQS的亲缘关系较近,2个DnSQS蛋白在进化上相对保守。(3)不同组织的薯蓣皂苷元含量存在差异,其含量大小依次为叶>根状茎>地上茎>根;DnSQS1与DnSQS2基因在不同组织中的表达也具有显著差异,其中DnSQS1在地上茎中表达水平最高,DnSQS2在叶中表达水平最高。(4)以激素MeJA、ABA、SA、Eth及非生物胁迫H     

New species of Phaeoramularia, Pseudocercospora and Stenella from Western Ghats of India

Four new species of the hyphomycete genera Phaeoramularia viz. Ph. caesalpinae, Pseudocercospora viz., Ps. tiliacearum, Stenella, viz. S. argyreiae and S. grewiae occurring on Caesalpinia bonducella Fleming (Caesalpiniaceae), Grewia sp. (Tiliaceae), Argyrea sp. Lour (Convolvulaceae) and Grewia sp. L. (Tiliaceae), respectively are described and illustrated here. All these fungi were collected from Western Ghats of India.