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Objective To obtain the Hiwi gene encoding full-length and construct human Hiwi adenoviral vectors carrying green luorescence protein (GFP), and to establish foundation for a further study on Hiwi function and mechanism of inducing leukemia stem cell differentiation and apoptosis.Methods All coding areas of human Hiwi gene full length were amplified using method of overlapping extension PCR technology, and the full length coding aeras were inserted into the vector of Flag-IRES-hrGFP carrying GFP with Gateway technology to construct pDown-Hiwi-3 × flag-IRES-hrGFP. The cloning vector pDown-Hiwi-3 × flag-IRES-hrGFP and expression vector pAV. Des1d were used for homologous recombination reaction to obtain recombinant adenovirus vector pAV.Ex1d-Hiwi-3× flag-IRES-hrGFP.The positive clones were selected by PCR to extract the recombinant adenovirus plasmid and to pack into recombinant Ad-Hiwi-3 × flag-IRES-hrGFP adenovirus. Results The human recombinant Hiwi was successfully cloned and the recombinant adenovirus vector pAV.Ex1d-Hiwi-3×flag-IRES-hrGFP was found to be successfully constructed via restriction enzyme digestion and sequencing methods. The adenovirus vector pAV.Ex1d-Hiwi-3×flag-IRES-hrGFP was transfected into the HEK293A cells using lipofectamine mediated gene transfection method. Under fluorescence microscope, the transfected cells with green fluorescence could be observed.Conclusion The expression plasmid of adenovirus vector pAV.Ex1d-Hiwi-3 × flag-IRES-hrGFP is successfully constructed and it can express in HEK293A cells.
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Objective To construct a lentiviral vector over-expressing β-catenin gene by multisite Gateway technology and confirm its effect.Methods By using multisite Gateway clone technique,the entry clone of pDown-Ctnnb1 was constructed using BP recombination reaction.Then,LR recombination reaction was performed among pUp-EF1A,pDown-Ctnnb1,pTail-IRES/DsRed-Express2 and pLV.Des3d.P/puro to generate an expression clone of pLV.EX3d.P/puro-EF1A＞Ctnnb1 ＞IRES/DsRed-Express2.In each step,PCR and sequencing analysis were used to verify the constructions.When it was verified that plasmids were transfected into 293T cells,PT-PCR was performed to determine the mRNA level of β-catenin gene.Results Both PCR and sequencing analysis revealed that β-catenin over-expression gene was inserted into the target site and the insertion sequence was perfectly corrected.The RT-PCR results showed that the expression of β-catenin gene was significantly upregulated.Conclusion The lenvivirus-mediate β-catenin over-expression gene was successfully constructed..
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Objective To construct a lentiviral vector carrying angiopoietin-1 (Ang-1) and DsRed gene, and to package a virus particles. Methods The Ang-1 lentiviral vector with DsRed (PLV.Ex3d.P/puro-CMV>Ang-1>IRES/DsRed-Express2) was constructed by Gateway technology, and identiifed by PCR and gene sequencing. The lentiviral vector was mixed with helper vector pLV/helper-SL3, pLV/helper-SL4 and pLV/helper-SL5 by Lipofectamine 2000 to prepare DNA-Lipofectamine?2000 complexes. The complexes were then added to transfect 293FT cells and package virus. The virus titers and infection ef-ifciency were determined by lfuorescence expression. Results Ang-1 lentiviral vector PLV.Ex3d.P/puro-CMV>Ang-1>IRES/DsRed-Express2 was constructed successfully as identified by PCR and gene sequencing. Lentivirus with high-efficiency infection was produced by transfection to 293FT cells and the virus titer was 5×108 TU/ml. Conclusions The recombinant len-tiviral vector for Ang-1 was successfully constructed by Gateway technology and the lentivirus with high-efifciency infection packaging can be used for further experiment of Ang-1 gene.
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Objective To construct cDNA entry library and cDNA expression library of Armillifer agkistrodontis (A.) nymphs and make a preliminary immunoscreening for the cDNA expression library.Methods The nymphs were collected from the Kunming mice infected experimentally with A.agkistrodontis eggs and the total RNA were extracted from the nymphs using TRIzol Reagent.After purifying the mRNA,the synthesized cDNAs were cloned into the donor vector pDONR222 by BP reaction of Gateway technology and the recombinants were transformed into the DH10B cells by electroporation,the cDNA entry library was obtained.Next,the expression vector pDEST17 was ligated with entry clones by LR reaction,and the recombinants were transformed into the BL21 (DE3) cells.Hence,the cDNA expression library was constructed.Then,the expression library was immunoscreened with the mixed sera of mice infected with A.agkistrodontis,and the insertions of positive clones were sequenced.After that,the open reading frame(ORF) of positive slone sequence,the homology of the screened genes and their encoded proteins were analyzed by Finder and BLAST (basic local alignment search tool) program of National Center of Biotechnology Information(NCBI),and the discovered new genes were submitted into the GenBank.Besides,the physico-chemical properties,secondary structure and B cell epitopes of encoded proteins were also analyzed by bioinformatics software.Results The average titer and total clones of the cDNA entry library were 1.45 × 105 CFU/ml(colony-forming unit,CFU) and 1.74 × 106 CFU,respectively,and the range of fragment length of the inserted cDNA was between 0.2-4.0 kb,with an average of 1.4 kb.The total clones of cDNA expression library were 1.00 × 105 CFU,and the fragment length of the inserted cDNA was between 0.3-2.2 kb,with an average of 1.0 kb.Five positive clones,coded S1,S5,A1,D1 and F1,respectively,were obtained through preliminary immunoscreening.The sequence and homology of the five positive clones were sequenced and analyzed by BLAST program.No significant similarities were found in pentastomida species,which meant that they were all novel genes of A.agkistrodontis.The gene sequences were submitted to GenBank,with the accession number from JQ180451 to JQ180455.Also,results obtained by bioinformatics software showed that the predictive encoding proteins were all potential to be valuable recombinant diagnostic antigens.Conclusions The cDNA library of A.agkistrodontis nymphs is successfully constructed,and five new genes of A.agkistrodontis are discovered.The establishment of cDNA library and the discovery of the new genes will lay a foundation for further studying the gene functions and screening the immunodiagnostic antigens.