The Construction and Identification of Eukaryotic Expression Vector pEGFP-N1-hTERT

[Objective] The aim of this study is to construct eukaryotic expression vector pEGFP-N1-hTERT and observe its expression in eukaryotic cells.[Method]The eukaryotic expression vector pEGFP-N1-hTERT was constructed with pC1-neo-hTERT and pEGFP-N1 plasmids,and the accuracy of human telomerase reverse transcriptase(hTERT)gene fragment was confirmed by double enzyme digestion and DNA sequencing analysis.After transfecting pEGFP-N1-hTERT into rat fetal neural stem cells(NSCs),the protein localization of human telomerase reverse transcriptase were indirectly observed through green fluorescent protein in the cells,and the correctness of constructed pEGFP-N1-hTERT was certificated by RT-PCR and Western Blot analysis.[Result]The eukaryotic expression vector pEGFP-N1-hTERT had correct structure and could express in eukaryotic cells.[Conclusion]This study laid a foundation for the establishment of immortalized NSCs line in rats.

Construction and Preliminary Identification of Eukaryotic Expression Vector of Cryptosporidium parvum miR-2980

[Objective] This study aimed to construct and preliminarily identify the eu- karyotic expression vector of Cryptosporidium parvum miR-2980. [Method] The cp-miR- 2980 precursor was amplified from C. parvum genomic DNA and cloned into pMD18- T vector. The amplified precursor was then subcloned into pVAX I vector and identi- fied with restriction endonuclease digestion and sequencing. The recombinant plasmid pVAX-miR2980 was transfected into HCT-8 cells. Total RNA was extracted and the expression of cp-miR-2980 was evaluated by RT-PCR detection. [Result] The results showed that the recombinant eukaryotic expression vector pVAX-miR2980 was suc- cessfully constructed, which can express cp-miR-2980 in HCT-8 cell. [Conclusion] This study laid the foundation for further exploring the biological function of cp-miR-2980.

Construction of Eukaryotic Expression Vector for Pig Ghrelin Gene

[Objective] This study aimed to investigate the functions of transgenic growth related gene in pig growth. [Method] A pair of primers containing Nhe I and Hind Ⅲ restriction sites were designed by referring to the pig Ghrelin mRNA sequence published in Genbank. Total RNA was extracted from the small intestine tissue of 13/17 Robertson translocation heterozygous pig, and then was purified and used as the template in later RT-PCR reaction to amplify the full-length pig Ghrelin gene. The correct pig Ghrelin gene fragment was cloned into the pMD19-T simple vector for sequencing analysis. The obtained full-length cDNA of pig Ghrelin gene fragment was digested with both Nhe I and Hind Ⅲ, and then was linked into the eukaryotic expression vector pEGFP-N1 to obtain the recombinant plasmid pEGFPGhrelin. The recombinant plasmid was transected into the fibroblast cells to detect the fluorescence labeled gene expression. [Result] The nucleotide sequence extracted from 13/17 Robertson translocation heterozygous pig was the same as expected; and the eukaryotic expression vector pEGFP-Ghrelin was successfully constructed. [Conclusion] The eukaryotic expression vector constructed in this study can be further used in research on transgenic pigs, but also lays foundation for research on the regulatory mechanism of Ghrelin gene.

Construction of PR domain eukaryotic expression vector and its inhibitory effect on esophageal cancer cells

Objective：PR domain is responsible for the tumor suppressing activity of RIZ1.The study aimed to construct human PR domain eukaryotic expression vectors,transfect human esophageal cancer cells （TE13）,and evaluate the anticancer activity of PR domain on human esophageal cancer TE13 cells.Methods：First,mRNA was extracted from human esophageal cancer tissue by RT-PCR,then reversetranscribed to cDNA.After amplifying from the DNA template,PR domain was linked to T vector.Second,after extraction,PR domain was cut using enzyme and linked to pcDNA3.1（＋）.Then,the plasmid was transfered to Trans1-T1 phage resistant competent cells,following by extracting the ultrapure plasmid,and transfecting into TE13 cells.In the end,the protein expression of pcDNA3.1（＋）/PR domain in TE13 was detected by Western blot,and the apoptosis of TE 13 by technique of flow cytometry.Results：More than 5,000 bp purposed band of pcDNA3.1（＋）/PR domain plasmid was found by agarose gel electrophoresis.After transfection,the PR domain （molecular weight of about 28 Da） was found only in 3,4 and 5 groups by Western blot.Flow cytometry assay showed apoptosis in experimental group was significantly more than that in the control group （P＜0.05）.Conclusions：The PR domain eukaryotic expression vector was constructed successfully.The protein of the PR domain could be expressed in esophageal cancer TE13 cells firmly after transfection,and a single PR domain could promote apoptosis of TE13 cells.

Gene Cloning of Murine α-Fetoprotein Gene and Construction of Its Eukaryotic Expression Vector and Expression in CHO Cells

To clone the murine α fetoprotein (AFP) gene, construct the eukaryotic expression vector of AFP and express in CHO cells, total RNA were extracted from Hepa 1 6 cells, and then the murine α fetoprotein gene was amplified by RT PCR and cloned into the eukaryotic expression vector pcDNA3.1. The recombinant of vector was identified by restriction enzyme analysis and sequencing. After transient transfection of CHO cells with the vector, Western blotting was used to detect the expression of AFP. It is concluded that the 1.8kb murine α fetoprotein gene was successfully cloned and its eukaryotic expression vector was successfully constructed.

Cloning and construction of sense and antisense eukaryotic expression vector of human Pin1

Objective： To clone and construct eukaryotic expressing vectors of sense and antisense human Pin1 （hPinl） genes. Methods： Total RNA was extracted from MG-63 cells, then the hPinl cDNA was amplified by RT-PCR. The same time the sense and antisense hPinl genes were formed by binding BamH Ⅰ and Hind Ⅲ in cis and trans-directions. At the end they were cloned into the eukaryotic expressing vector pIRES2-EGFP in cis and trans directions using DNA recombinant technology. The recombinant vectors were further identified by digestion of BamHⅠ and Hind Ⅲ. Results： The results of sequencing showed that the orientation of the ligations and the reading frame were correct. After digested by BamH Ⅰ and Hind Ⅲ, two fragments exhibiting 5.3 kb and 0.99 kb were formed in sense and antisense eukaryotic expressing vectors. Electrophoretic results were completely coincident with theoretical calculation. Conclusion： Human Pin1 sense and antisense genes were successfully cloned and eukaryotic expressing vectors were successfully constructed.

Construction of bicistronic green fluorescent protein labeled pSELECT GFPzeo human bone morphogenetic protein 2 eukaryotic expression vector

Objective To construct green fluorescent protein (GFP)-labeled pSELECT-GFP zeohBMP2 eukaryotic expression vector.Methods The encoding fragment of hBMP2 gene was obtained from a recombinant plasmid pcDNA3.1/CT-hBMP2 by using polymerase

Construction of eukaryotic expression plasmid pEGFP-N1-WWOX and its transient expression in SMMC-7721 cells

Objective： To construct eukaryotic expression plasmid pEGFP-NI-WWOX and transiently express it in SMMC-7721 cells. Methods： Total mRNA was extracted from normal human liver tissue. RT-PCR was used to amplify the aimed segments WWOX cDNA which was then digested with Hindlll and BamHI and inserted into a eukaryotic expression plasmid pEGFP-N 1 to construct pEGFP-N 1-WMVOX. The constructed plasmid was transfected into SMMC-7721 cells by lipofectamine 2000 - mediated transfer method. The expression of WWOX in transfected SMMC-7721 cells was detected 24, 36 and 48 h post-transfection with fluorescence microscope and the expression level of WWOX mRNA in transfected SMMC-7721 cells was assay by using RT-PCR. The change of MMWOX expression and cell proliferation rates were detected by immunocyto- chemistry and MTT methods respectively. Results： The results showed pEGFP-N1-WWOX was successfully constructed and expressed transiently in SMMC-7721 cells. At 48th hour post-transfection, the number of positive cells was increased significantly and much brighter green fluorescence could be detected, while no green fluorescence was detected in the control group. In SMMC-7721 cells transfected with pEGFP-NI-WWOX a high level of porcine WWOX was detected. WWOX ex- pressed by transfected cells could significantly inhibit the proliferation of SMMC-7721 cells. Conclusion： pEGFP-N1-WWOX was expressed successfully in SMMC-7721 cells, which suggested that might be used as a new therapeutic method for liver cancer.

Construction of Eukaryotic Expression Plasmid of bFGF Gene in Rats and Its Expression in Tenocytes

The bFGF plays an important role in embryonic development of tendons and ligaments and in the healing of injuried tendons and ligaments. The eukaryotic expression plasmid of rat basic fibroblast growth factor （bFGF） gene was constructed in order to further investigate the bFGF function in molecular regulatory mechanism in the repair of tendons and ligaments and to provide the foundation for the clinical application. The cDNA fragments of bFGF were cloned from the skin of rats by RT-PCR, and recombinated to the pMD18-T vector. The cDNA encoding bFGF was cloned from the pMD18-T vector by RT-PCR, digested with restriction enzyme EcoR Ⅰ, Pst Ⅰ and bound to eukaryotic expression plasmid plRES2-EGFP to construct eukaryotic expression plasmid plRES2-EGFP-bFGF. The plRES2-EGFP-bFGF was transfected into the tenocytes by lipid-mediated ransfection technique. MTT test was used to detect the biological activity of bFGF in supernatants after the transfection. The expression of type Ⅰ and Ⅲ collagen genes was detected by using RT-PCR. It was verified that the plRES2-EGFP-bFGF was successfully constructed, and its transfection into tenocytes could significantly enhance the biological activity of bFGF, and increase the expression of type Ⅰ and Ⅲ collagen mRNA, suggesting that plRES2-EGFP-mediated bFGF gene therapy was beneficial to the repair of tendons and ligaments.

猪催乳素的真核表达与生物活性验证

【目的】催乳素(Prolactin,PRL)具有广泛的生理调节作用,但其多效性机制仍不清楚。为了更好地研究猪PRL的多效性,本研究制备猪源PRL真核重组蛋白并验证其生物活性。【方法】利用分子克隆技术将猪PRL基因克隆到慢病毒表达载体pCDH-CMV-MCS-EF1-GFP+Puro中,经慢病毒包装获得携带猪PRL基因的PRL-慢病毒;用浓缩的PRL-慢病毒感染CHO-K1细胞,经嘌呤霉素筛选后,获得能够分泌PRL重组蛋白的阳性细胞系CHO-K1-PRL;利用镍柱亲和层析法对重组蛋白进行纯化并进行LC-MS/MS质谱鉴定,利用HC11细胞体外培养体系验证PRL重组蛋白的生物活性。【结果】成功构建了携带猪PRL基因的pCDH-CMV-6His-PRL-6HisEF1-GFP+Puro慢病毒表达载体;包装及浓缩后的PRL-慢病毒滴度为9.9×10^(8) TU/mL,其感染的CHO-K1细胞经嘌呤霉素筛选后得到阳性细胞系CHO-K1-PRL;从CHO-K1-PRL细胞培养液中成功纯化出重组蛋白,质量浓度为50μg/mL,LC-MS/MS质谱分析的覆盖率达94%,鉴定为猪PRL重组蛋白;重组PRL具有促进HC11细胞增殖及酪蛋白表达的生物活性。【结论】构建的细胞系CHO-K1-PRL可稳定表达具有生物活性的猪重组PRL,为猪PRL功能的研究和生产应用奠定了基础。

多星韭AwCHI 1的克隆与分析及真核表达载体的构建

查尔酮异构酶(Chalcone isomerase,CHI)是类黄酮物质合成途径中的关键酶,能催化柚皮素查尔酮生成柚皮素,进而转化生成各种类型的黄酮类化合物。根据多星韭(Allium wullichii)转录组测序结果,运用PCR技术克隆获取多星韭查尔酮异构酶的编码基因(AwCHI 1),对基因序列进行分析,同时与真核表达载体pBI121进行连接,将其转入农杆菌GV3101感受态细胞中,完成农杆菌的转化。研究结果不仅为该基因的功能解析研究奠定了基础,也为多星韭类黄酮代谢途径的研究提供了重要基因资源。

持续高糖状态对Kv11.1离子通道蛋白表达的影响

目的:探讨持续高浓度葡萄糖干预对Kv11.1离子通道蛋白表达的影响。方法:①采用双酶切法和基因重建技术将HERG基因插入到表达绿色荧光蛋白的真核表达载体pEGFP-N1中,构建Kv11.1离子通道蛋白的表达载体pEGFP-N1-HERG并测序验证。②pEGFP-N1-HERG表达载体鉴定成功后经脂质体转染HEK293T细胞,并通过不同糖浓度(5、17.5、30mmol/L)干预细胞48h后流式细胞仪检测细胞HERG离子通道蛋白绿色荧光平均表达量。结果:流式细胞仪检测pEGFP-N1-HERG融合蛋白平均荧光强度于不同浓度葡萄糖持续干预后分别为218.87(5mmol/L)、174.83(17.5mmol/L)、142.90(30mmol/L),三组间比较差异有统计学意义(均P<0.05)。结论:持续高糖状态抑制Kv11.1离子通道蛋白的表达,为糖尿病患者长期高糖状态时QT间期延长提供理论依据并奠定实验基础。

绵羊GSTA2基因克隆、生物信息学分析及真核表达载体构建

为阐明绵羊谷胱甘肽S转移酶α2(Glutathione S-transferase alpha 2,GSTA2)基因功能,利用牛GSTA2基因序列设计引物,提取绵羊皮肤组织总RNA,应用RT-PCR、基因克隆、生物信息学对GSTA2基因进行研究,构建真核表达载体,转染绵羊皮肤成纤维细胞,应用qPCR技术检测GSTA2基因的表达。结果表明,克隆到绵羊GSTA2基因672 bp编码区序列(GenBank登录号:OR440604.1),编码223个氨基酸,分子量为25.39 ku。氨基酸比对和系统进化树分析表明,绵羊与牛的GSTA2相似度最高,达87.39%。GSTA2的二级结构以α-螺旋和无规则卷曲为主。构建的真核表达载体pcDNA3.1-GSTA2转染绵羊皮肤成纤维细胞后,GSTA2基因表达量极显著上调(P <0.001)。说明成功克隆了绵羊新基因GSTA2的CDS序列,并成功构建了其真核表达载体。

努比亚山羊Rheb基因克隆、生物信息学分析及真核表达载体构建

【目的】研究旨在对努比亚山羊大脑富集Ras同源物(Ras homolog enriched in brain,Rheb)基因进行克隆和分析,并构建其真核表达载体,为进一步揭示Rheb对努比亚山羊骨骼肌调控的分子机理奠定基础。【方法】试验采用RT-PCR方法从努比亚山羊背最长肌组织中扩增Rheb基因,经琼脂糖凝胶电泳及测序验证正确后进行生物信息学分析,同时构建该基因真核表达载体,转染细胞后进行实时荧光定量PCR检测来验证所构建载体的正确性。【结果】努比亚山羊Rheb基因编码区序列长度为555 bp,编码184个氨基酸,Rheb蛋白分子式为C 910 H 1456 N 236 O 279 S 6,分子质量为20359.34 u,原子总数为2887,理论等电点为5.93。Rheb蛋白属于稳定的亲水性蛋白,不包含跨膜结构域。蛋白二级结构预测结果显示,努比亚山羊Rheb蛋白中α-螺旋、β-转角、延伸链和无规则卷曲分别占40.76%、7.07%、22.83%和29.35%。构建的真核表达载体pcDNA3.1-Rheb转染山羊骨骼肌细胞后,与空载体组相比,Rheb基因表达量极显著升高(P<0.01)。【结论】本试验成功克隆努比亚山羊Rheb基因编码区序列,并构建pcDNA3.1-Rheb真核表达载体,这为深入理解Rheb基因在努比亚山羊肌肉中的作用提供了理论支持。

小鼠SGK3真核表达载体的构建及鉴定

目的构建含有小鼠血清和糖皮质激素诱导蛋白激酶3(serum and glucocorticoid-induced protein kinase 3,SGK3)基因的真核表达载体pcDNA3.1-MYC-SGK3-mCherry,并观察和验证其在转染细胞HEK293中的表达。方法通过聚合酶链式反应将实验室保存的真核表达质粒pcDNA3.1-MYC-SGK3中目的基因SGK3与mCherry融合并扩增出来,然后定向克隆至pcDNA3.1-MYC质粒中,经限制性内切酶消化和测序证实后,通过脂质体法转染HEK293细胞,Western blotting法检测目的基因的蛋白表达情况。结果测序结果与之前预期结果相符,证实pcDNA3.1-MYC-SGK3-mCherry真核表达载体构建成功。Western blotting结果显示,转染pcDNA3.1-MYC-SGK3-mCherry的HEK293细胞出现清晰的阳性反应条带,说明目的片段成功表达。结论pcDNA3.1-MYC-SGK3-mCherry真核表达载体构建成功。

新型冠状病毒Nsp1基因真核表达载体的构建及对宿主蛋白质翻译的影响

非结构蛋白1(Non-structural protein 1,Nsp1)作为新型冠状病毒(Severe acute respiratory syndrome coronavirus-2,SARS-CoV-2)的毒力决定因子,在调控冠状病毒复制方面有重要作用。为更有效地研究SARS-CoV-2 Nsp1蛋白的生物学功能,成功构建SARS-CoV-2Nsp1基因的真核表达载体,并验证其抑制宿主及外源蛋白质翻译的功能。通过PCR技术扩增SARS-CoV-2Nsp1基因后,利用同源重组技术将其连接至pEGFP-N1载体上。经双酶切和测序结果鉴定,SARS-CoV-2Nsp1基因成功克隆至pEGFP-N1载体上。将重组质粒pEGFP-N1-SARS-CoV-2-Nsp1转染至HEK-293T细胞和HeLa细胞中,经嘌呤霉素标记后,利用Western Blot和考马斯亮蓝染色检测重组质粒的表达以及嘌呤霉素信号。结果表明,重组质粒pEGFP-N1-SARS-CoV-2-Nsp1在HEK-293T细胞和HeLa细胞中成功表达,并验证其抑制宿主蛋白质和外源转入细胞蛋白质的翻译,为更深入研究SARS-CoV-2 Nsp1蛋白的功能奠定基础。

TFAP2A基因重组真核表达载体的构建及鉴定

目的构建转录因子增强子结合蛋白-2α的真核表达载体并进行鉴定,为TFAP2A的后续研究提供有效工具。方法采用限制性内切酶BamHⅠ和HindⅢ对真核表达载体CV702质粒进行酶切获得线性化载体;通过PCR扩增制备TFAP2A的cDNA片段,将线性化载体和TFAP2A的cDNA扩增产物进行体外环化连接,构建CV702-TFAP2A重组质粒。将连接产物进行细菌转化,挑取平板上的单克隆进行PCR鉴定,对阳性克隆进行测序及结果分析。将CV702-TFAP2A重组真核表达载体转染乳腺癌细胞MDA-MB-231,通过Western blot检测TFAP2A的表达效率。结果菌落PCR扩增和测序结果显示,CV702-TFAP2A重组真核表达载体构建成功;Western blot结果与Image J灰度值分析结果显示,与CV702对照载体相比,转染CV702-TFAP2A重组质粒的MDA-MB-231中的Flag-TFAP2A蛋白相对表达量更高(P<0.05)。结论成功构建CV702-TFAP2A的重组真核表达载体,证实转染CV702-TFAP2A的细胞中Flag-TFAP2A的表达水平升高。