PRK基因原核表达质粒的构建

以拟南芥cDNA为模板,扩增出PRK基因,构建重组质粒pET-28a（＋）-PRK转化大肠杆菌DH5α。经PCR鉴定和酶切鉴定筛选出阳性克隆,将阳性克隆的质粒转化到大肠杆菌表达载体BL21中,构建PRK基因原核表达载体。测序结果表明pET-28a（＋）-PRK载体构建成功。     

平邑甜茶MhVPE基因ihpRNA干扰载体的构建及转拟南芥验证

 根据平邑甜茶液泡加工酶（vacuolar processing enzyme）基因MhVPE（GenBank登录号为FJ891065）cDNA序列,设计两对含有酶切位点的特异性引物F1/F2和R1/R2,以pMD-MhVPE质粒为模板,分别克隆了用于构建干扰载体的正反义片段pMD-F和pMD-R。将该正反义片段分别插入表达载体pART27的相应位置,构建成了含有内含子发夹结构的ihpRNA表达载体pART-RNAi-MhVPE。通过农杆菌介导,用花序浸泡法转化拟南芥进行验证,经过抗性筛选和PCR检测,得到17株转基因阳性植株;半定量RT-PCR结果显示所获得的转基因拟南芥植株中AtVPE同源基因的表达量明显降低,表明该干扰载体能够有效抑制VPE基因的表达,MhVPE基因的ihpRNA干扰载体构建成功,为进一步鉴定该基因的功能奠定了基础。     

CRISPR-Cas9系统敲除甜瓜ACC合成酶基因表达载体的构建

以甜瓜品种"老汉瓜"为试材,采用CRISPR-Cas9基因组编辑技术,研究了构建CRISPR-Cas9系统敲除甜瓜ACC合成酶基因表达载体的方法,以期获得高效的敲除甜瓜基因的基因组编辑技术。结果表明:以甜瓜ACC合成酶的基因设计出引物后,将其构建到pP1C.4载体上,用热激法将连接产物转化到大肠杆菌中,筛选的阳性克隆测序验证为最终载体。     

川芎甜菜碱醛脱氢酶cDNA的克隆及其植物表达载体的构建

以川芎为试材,从叶片中提取总RNA,经过RT-FCR获得甜菜碱醛脱氢酶(Betaine aldehyde dehydrogenase)基因的cDNA,纯化后与pMD18-T载体连接,转化大肠杆菌Top10,获得甜菜碱醛脱氢酶全长基因序列,以期构建植物表达载体.结果表明:甜菜碱醛脱氢酶全长核苷酸长度为1 527 bp,编码508个氨基酸.与GenBank中已发表序列HM35276进行比较,核苷酸同源性为100％.将该基因片段克隆到植物表达载体pBI121中,构建重组质粒pBI121/Betaine aldehyde dehydrogenase,并将所获重组质粒经过双酶切和PCR处理后进行序列测定,证实表达载体上含有目的片段,且连接、构建正确,为BADH的进一步表达奠定了基础.     

毛尖紫萼藓GH394基因克隆、表达载体的构建

利用PCR技术,以毛尖紫萼藓总RNA为模板,扩增出上、下游分别加入BamHI、SacⅠ酶切位点的GH394(657 bp)基因CDS区全长序列,采用pMD18-T Vector、pRI 101-AN Vector构建了该基因克隆、表达载体,并将重组载体质粒转化到大肠杆菌(Escherichia coli)DH 5α和根癌农杆菌(Agrobacterium tumefaciens)工程菌株GV3101中,并选用X-gal、IPTG和利福平(Rifampicin,Rif)、卡那霉素(Kanamyein,Km)筛选阳性菌株。结果表明:已成功构建pMD-GH394克隆载体和pRI 101-AN-GH394表达载体并将重组质粒转入目的菌株中;该试验为后续实现毛尖紫萼藓GH394基因抗旱预期功能的验证,奠定了良好的试验基础。     

药西瓜(Citrullus colocynthis)UDP-糖基转移酶基因表达分析

以药西瓜为试材,采用连接转化、双酶切等方法,在前期克隆得到的2个药西瓜UDP-糖基转移酶基因UDP-E1、UDP-E2的基础上,将目的基因UDP-E1、UDP-E2与pET28a连接,构建重组质粒pET28a-UDP-E1和pET28a-UDP-E2,将重组质粒转化至E.coli BL21中,经过不同浓度的IPTG诱导,期望出现目的蛋白条带,且上清中的目的蛋白条带较沉淀与对照组明显。结果表明:成功构建原核表达重组质粒,IPTG浓度为1.0 mmol·L~(-1)时,UDP-E1的融合蛋白分子量约为49 kDa,IPTG浓度为0.8 mmol·L~(-1)时,UDP-E2的融合蛋白分子量约为32 kDa,目的蛋白在大肠杆菌BL21中得到了高效表达。     

甘蔗黄叶病毒P0基因的克隆与原核表达及抗血清制备

根据已发表ScYLV-P0基因系列设计特异性引物,应用RT-PCR技术从甘蔗病叶的mRNA扩增得到目的DNA片段.以pET32a（＋）为原核表达载体,构建重组表达质粒pET32a-P0.经过双酶切鉴定和DNA测序后,将重组表达质粒转入大肠杆菌BL21 （DE3）pLySs,在30℃培养条件下IPTG诱导表达.通过SDS-PAGE电泳检测融合蛋白表达情况.表达结果显示,在该表达系统中,融合表达蛋白P0是以包涵体形式的蛋白存在;P0融合蛋白大小约45kDa,与P0开放阅读框的理论推算值29.991 kDa加上载体自身蛋白约18 kDa相符,用Ni2＋-NTA琼脂糖亲和层析纯化融合蛋白,免疫家兔制备出抗血清,通过酶联法（ID-ELISA）测定本实验制备的ScYLY-P0抗血清工作浓度为1：25000.     

甘蓝中硫氧还蛋白编码基因THL1的分子特性及表达研究

采用PCR和RT2PCR技术, 以‘E1’甘蓝基因组DNA和柱头cDNA为模板对THL1基因进行扩增克隆, 得到的片段长度分别为732 bp和455 bp。序列分析表明, 克隆的DNA和cDNA序列与甘蓝‘西园四号’THL1的DNA和cDNA同源性分别为97.9%和98.3%, 两条序列内含子的大小不同; 同时, 前者第2内含子不符合典型的GT2AG规则: 即第2个内含子3′端碱基为AT。将THL1基因cDNA序列定向克隆到原核表达载体pET-43.1a ( + ) , 构建融合表达质粒pET43.1a ( + ) -THL1, 在大肠杆菌BL21中表达出分子量为74kD的融合蛋白, 经胰岛素检测, THL1有氧化还原活性, 表明THL1在大肠杆菌中得到了正确表达。     

携带黄瓜花叶病毒外壳蛋白基因的双元载体构建

以黄瓜花叶病毒外壳蛋白基因为目的基因,以大肠杆菌DH5α为表达载体体外操作寄主菌,农杆菌LBA4404为最终双元载体寄主菌。将RT-PCR获得的目的基因片段连接到pMD18-Tsi mple Vectoer上,冻融法转化到大肠杆菌扩繁后,经限制性核酸内切酶酶切插入表达载体适宜酶切位点上,重组质粒DNA经冻融法转化到只含辅助质粒的根癌农杆菌中得到工程菌,完成含目的基因的双元载体构建,为培育抗CMV病毒的番茄品种打下基础。     

Construction of mouse pdx-1 gene eukaryotic expression vector and its expression in embryonic stem cells

AIM: To clone mouse pdx-1 gene and construct its eukaryotic expression vector for expression of pdx-1 in mouse embryonic stem cells.METHODS: Mouse pdx-1 cDNA fragment was amplified with polymerase chain reaction (PCR) from mouse pancreatic cDNA. The purified fragment was recombinated with a eukaryotic expression vector carrying enhanced green fluorescent protein, pEGFP-N1. The pdx-1 cDNA fragment was inserted into the multi-clone sites of the vector to construct a new plasmid, pEGFP/pdx-1. E.colli strain DH5α was transfected with the new recombinant plasmid to expand it. Plasmid DNA extracted from the expanded DH5α was identifed by cutting with Hind Ⅲ, BamHⅠ nuclease and by DNA sequencing. Identified plasmid DNA was transfected into mouse embryonic stem cell line MESPU13 by carrying with liposome. RESULTS: A 876 bp cDNA fragment was amplified from mouse pancreatic cDNA by PCR and it was inserted into the vector pEGFP-N1 correctly. The fragment was defined to be pdx-1 gene by nuclease digestion and DNA sequencing. Mouse embryonic stem cell line MESPU13 was transfected with the new recombinant plasmid DNA. The green fluorescent protein report gene and pdx-1 gene expressed in transfected mouse embryonic stem cells within 24 h. CONCLUSION: Mouse pdx-1 gene is cloned and its recombinant eukaryotic expression vector carrying green fluorescent protein is constructed successfully. It provides a useful tool for further research on the function of pdx-1.     

Impact of HBV DNA level in serum on the cloning efficiency of HBV full length genome

AIM: To compare the cloning efficacy of full-length HBV genome amplified by single fragment PCR and two fragment PCR for choosing the suitable method for full-length HBV genome cloning. METHODS: To amplify the full-length HBV genome from 85 sera sample of HBV patients, single fragment PCR and two fragment PCR were conducted. The products were cloned into the vector and sequenced after identified with double enzyme digestion. At the same time, the titers of 85 samples were detected by real-time PCR. RESULTS: Compared with two fragment PCR, single fragment PCR requested higher level of sera HBV DNA for successful amplification of full-length HBV genome, and the efficacy of single fragment PCR was lower than that of two fragments PCR (P<0.05). The mutation ratio of single fragment PCR was 1.13 bp/kb, and the sensitivity of single fragment PCR was 102 original templates. The efficacy of amplification was 80% if the amounts of template exceed 103, but the efficacy was low under this value. CONCLUSION: The efficacy of amplification is affected by the level of sera HBV DNA. The titers of sera HBV DNA are the proof for choosing a suitable PCR method. If the level of sera HBV DNA was more than 106 copies/L, single fragment PCR will be suitable. If the level of sera HBV DNA was less than 106 copies/L, two fragments PCR will be better.     

果实特异启动子调控薄皮甜瓜ACC合成酶cDNA反义表达载体的构建

应用反义RNA技术抑制甜瓜成熟过程中内源乙烯的合成,从而培育耐贮运品种是解决甜瓜延熟保鲜难题的可行新方法。根据GenBank中甜瓜、黄瓜ACC合成酶基因氨基酸保守序列设计引物,从成熟的薄皮甜瓜(齐甜1号)果肉组织中提取总RNA,经RT-PCR扩增得到约0.7kb的ACC合成酶cDNA片段,将其克隆到质粒载体pGEM-TEasy中,测序表明,该基因为777bp,编码258个氨基酸;从番茄(东农706)叶片组织中提取总DNA,经PCR扩增得到约2.2kb的E8基因片段,将其克隆到质粒载体pGEM-TEasy中,测序表明,该基因为2192bp;以pCAM2301为起始植物表达载体,pCAM-GT为中间载体,成功构建了果实特异启动子(E8)调控薄皮甜瓜ACC合成酶cDNA反义表达载体,采用冻融法将其转入根癌农杆菌LBA4404,得到了完整的Ti质粒表达载体系统。     

草莓镶脉病毒的PCR检测及特异片段的序列分析

用CTAB法从感病的草莓叶片中提取总DNA,以其为模板经PCR扩增获得与预期片段大小一致长约600bp的扩增产物,同时优化PCR反应程序,获得单一特异条带;通过总DNA浓度梯度稀释,进行PCR扩增,结果表明能检测到2.5μg叶组织中病毒的存在。回收PCR特异扩增产物,与pMD18-T载体连接,并进行转化、重组克隆的筛选、重组质粒的酶切鉴定和序列测定。扩增片段序列与已报道SVBVCP基因序列(序列号:Nc_001725)的核苷酸同源性为89.2%,氨基酸同源性为96.3%。该特异片段序列在GenBank中的登记号为AY862389。     

Construction of an eukaryotic expression vector encoding human granzyme B and it's expression in Hep2 cells

AIM: To construct pVAX1-GrB. METHODS: Lymphocytes from human laryngeal carcinoma tissue were separated from tumor tissue. The fragment of granzyme B (GrB) was amplified by RT-PCR and was recombined to the downstream of T7 promoter in the vector pVAX1. The construction was transfected into Hep2 cells with lipofectamine 2000. The expression of protein was identified by indirect immunofluorescent antibody assay. RESULTS: It has been proved that the sequence of the RT-PCR product was totally consistent with the data of GenBank by DNA sequencing analysis. The GrB cDNA fragment was cloned into the vector of pVAX1 in the right direction and the open reading fragment of GrB was maintained. The target protein was detected in the transfected Hep2 cells. CONCLUSION: The pVAX1-GrB plasmid was successfully constructed and expressed.     

番木瓜雄性性别的RAPD和SCAR标记

利用RAPD标记技术鉴定番木瓜雄性性状。在214条随机引物中,用引物Z18扩增得到1条雄性多态性片段,此片段存在于试验所用材料的所有雄株中而两性株和雌株没有,将其命名为Z18-1000。根据对该片段的序列分析结果重新设计了2对引物将RAPD标记成功转化成了SCAR标记,并命名为SD-1000。     

桃早熟芽变品种‘大观一号’的RAPD分析及其特异片段的克隆

利用140个单个和混合随机引物对桃布日早生及其早熟芽变品种'大观一号'基因组DNA的多态性进行RAPD分析。其中有一个引物能检测出两者之间DNA的多态性，在1．1kb处'大观一号'多了一条特异性条带，将该片段克隆到pUC19载体，并作了酶谱分析。     

马铃薯块茎组织特异性启动子GBSS的克隆及序列分析

利用PCR技术从马铃薯陇薯3号基因组DNA中扩增出长度约为600 bp的DNA片段,经与T载体连接,测序表明,克隆到的DNA片段大小为599 bp,该序列与Genebank中已公布的GBSS启动子序列同源性为99.67%;采用植物顺式调控元件数据库PLACE和PlantCare对其进行序列分析,结果表明,该片段含有启动子的保守序列TATA-box和CAAT-box。此外,还具有诸如TAACAAA、CTAACAC、CTCTT及CACT等序列,而这些特异序列可能是基因特异表达所必须的。     

山东寿光地区番茄黄化曲叶病毒外壳蛋白基因克隆及其在大肠杆菌中的表达

利用双生病毒简并引物PA/PB,对山东寿光地区保护地疑似感染番茄黄化曲叶病毒（TYLCV）的番茄植株进行PCR检测,结果证明番茄病叶由TYLCV侵染所致。以提取的病叶总DNA为模板,扩增得到长约770 bp的TYLCV-CP基因片段,克隆至pEASY-T1 Simple载体,然后用Xho I和EcoR I将其切下并插入到pET-32a表达载体中,构建了寿光地区TYLCV分离物的外壳蛋白基因原核表达载体,转入大肠杆菌BL21（DE3）,经IPTG（异丙基-β-D-硫代吡喃半乳糖苷）诱导获得了50 kD重组蛋白,Ni2+-NTA亲和层析纯化和Western印迹分析证明目的蛋白为TYLCV外壳蛋白,且具有良好的抗原活性。     

Screening and sequencing of the novel differential gene in leptospira serovar lai

AIM:To amplify and analyze the differential DNA fragment between pathogenic leptospira serovar lai and nonpathagenic leptospira serovar patoc I.METHODS:The previously subtract ive DNA fragment only exist ing in leptospira serovar Lai was amplified by cassette ligation and semi-nested PCR.The obtained gene was sequenced and searched homologically.In addition,the deduced amino acid was analyzed and the secondary stracture of protein was predict ed.RESULTS:The 580 bp DNA fragment, which deposited in GenBank (AF495587), was cloned, and four overlapping open reading frames (ORF) was contained. The high homology with conserved hypothetical protein streptococcus pyogenes was found.CONCLUSION:This study lays foundation for deeply exploring biological actions of new gene and pathogenic mechanism of leptospira serovar lai.