IDENTIFICATION AND SEQUENCE OF A cDNA CLONE CORRESPONDING TO A GENE INVOLVED IN DEVELOPMENT OF UNDARIA PINNATIFIDA

During the induction of gamete-producing gametangia, induced gametophytes werecollected at 4 days intervals (0,4,8, 12 d) and total RNAs were isolated by CsCl gradient ultracentrifu-gation. Some stage-specific expressed mRNAs were identified by differential display of mRNAs from dif-ferent developing stages of the gametophytes. The cDNA of one specific mRNA was verified, cloned andsequenced. This gene was specifically expressed during 4 days of induction, and had partial homologoussequence with tobacco IAA-binding protein gene. It suggests that this cDNA may represent a gene whichis related to the LAA regulating function during the development of the gametophytes.

玉米大斑病菌cDNA文库的构建及转录因子StMR1互作蛋白的筛选

【目的】筛选玉米大斑病菌(Setosphaeria turcica)转录因子的互作蛋白,解析黑色素调控转录因子StMR1调控玉米大斑病菌致病性的分子机制。为解析玉米大斑病菌侵染过程中转录因子的调控网络,阐明病菌的致病机理提供参考。【方法】收集玉米大斑病菌菌丝和孢子不同萌发阶段作为试验材料,采用Gateway方法构建玉米大斑病菌cDNA文库,使用同源重组的方法构建转录因子StMR1的诱饵载体,采用酵母双杂交技术筛选其互作蛋白并进行一对一验证。【结果】构建的玉米大斑病菌文库插入的平均片段长度大于1000 bp,初级文库及次级文库的库容量为1.2×107和1.04×107CFU,重组率为100%,可以用于酵母双杂交筛选。成功构建可以用于筛库的诱饵载体pGBKT7-StMR1,经初筛与复筛得到3个互作蛋白,一对一验证短链脱氢酶、糖基转移酶、富含亮氨酸重复序列蛋白均与转录因子StMR1存在互作。【结论】成功构建了丰富度高且质量好的玉米大斑病菌cDNA文库并筛选到了与转录因子StMR1互作的蛋白。

Applying a highly specific and reproducible cDNA RDA method to clone garlic up-regulated genes in human gastric cancer cells

AIM: To develop and optimize cDNA representational difference analysis (cDNA RDA) method and to identify and clone garlic up-regulated genes in human gastric cancer (HGC) cells. METHODS: We performed cDNA RDA method by using abundant double-stranded cDNA messages provided by two self-constructed cDNA libraries (Allitridi-treated and paternal HGC cell line BGC823 cells cDNA libraries respectively). Bam H I and Xho I restriction sites harbored in the library vector were used to select representations. Northern and Slot blots analyses were employed to identify the obtained difference products. RESULTS: Fragments released from the cDNA library vector after restriction endonuclease digestion acted as good marker indicating the appropriate digestion degree for library DNA. Two novel expressed sequence tags (ESTs) and a recombinant gene were obtained. Slot blots result showed a 8-fold increase of glia-derived nexin/protease nexin 1 (GDN/PN1) gene expression level and 4-fold increase of hepatitis B virus x-interacting protein (XIP) mRNA level in BGC823 cells after Allitridi treatment for 72h. CONCLUSION: Elevated levels of GDN/PN1 and XIP mRNAs induced by Allitridi provide valuable molecular evidence for elucidating the garlic's efficacies against neurodegenerative and inflammatory diseases. Isolation of a recombinant gene and two novel ESTs further show cDNA RDA based on cDNA libraries to be a powerful method with high specificity and reproducibility in cloning differentially expressed genes.

Characteristics of nucleotides and amino acids in cDNA sequence of xyloglucan endotransglycosylase cloned from Anthocephalus chinensis

Xyloglucan endotransglycosylase is an identified relaxation factor with functions of easing and extending of plant cell walls.Its activities are directly related to plant growth and elongation of organisms.Anthocephalus chinensis is a tall and fast growing evergreen tree species.We cloned the full cDNA sequence of AcEXT genes which is abundantly expressed in the cambium of A.chinensis.The sequence analysis of nucleotides and amino acids revealed the presence of a 1396 bp full cDNA sequence,including a 960 bp complete open reading frame（ORF） encoding a 320 amino acid protein.The deduced amino acid sequence of AcXET was homologous to the other known XET proteins and contained the conserved EIDFE catalytic site which was specific to all the XETs.Our data should serve as a foundation for further insight into AcXET gene molecular mechanisms during wood formation and cell wall engineering of woody plants.

cDNA clone and expression analysis of a-Tropomyosin during Japanese flounder （Parafichthys ofivaceus） metamorphosis

Tropomyosin （TM） plays a critical role in skeletal and cardiac muscle development and function. To assess the fimctional significance of a-TM in Japanese flounder （Paralichthys olivaceus） development and metamorphosis, cDNA from Japanese flounder was cloned and a-TM mRNA measured during development and metamorphosis. The full-length cDNA is 1 191 bp, including a 5＇- untranslated region of 114 bp, a Y-UTR of 222 bp, and an open reading frame of 855 bp encoding a polypeptide of 284 amino acids. Real-time quantitative PCR revealed that a-TM mRNA is initially expressed in unfertilized ovum, indicating the a-TM gene is maternal. Relatively low mRNA levels were observed in different embryonic stages. A higher level of a-TM mRNA was detected 3 days post hatching （dph）, while the highest level was measured at 29 dph （metamorphic climax） after which it declined towards the end of metamorphosis. The expression of a-TM mRNA was up-regulated in thyroid hormone-treated larvae at 36 dph, but there was no marked difference at other stages when compared to control animals. After thiourea treatment, the expression of a-TM mRNA declined slightly. These data provide basic information that can be utilized in further studies into the role of a-TM in P olivaceus development and metamorphosis.

白菜种子cDNA酵母文库的构建及BrTTG1互作蛋白的筛选及分析

【目的】通过构建白菜种子的cDNA文库,筛选WDR 40蛋白TRANSPARENT TESTA GLABRA 1(TTG1)的互作蛋白,探究TTG1参与MBW三元复合体调控种皮原花青素形成的分子机制。【方法】以棕籽白菜自交系‘B147’的种子为材料,提取总RNA并建立cDNA文库,通过gateway技术构建诱饵载体pGBKT7-TTG1并进行酵母双杂交筛库。【结果】酵母文库库容为1.2×10^(7)CFU,文库滴度是5.0×10^(7)CFU/mL,插入片段平均长度大于1000 bp,诱饵载体在酵母中无自激活活性。通过构建的诱饵载体pGBKT7-TTG1与构建的cDNA文库杂交,共获得了38个阳性互作蛋白,功能预测显示其中一个蛋白注释为MYB转录因子,注释为MYB73,序列分析结果显示该基因含有R2R3-MYB型抑制子保守基序C1和C2,推测该基因为白菜中参与种皮颜色形成的R2R3-MYB型抑制子,暗示着白菜中可能存在不同MYB转录因子参与的调控网络,影响着原花青素的形成。【结论】本研究构建了白菜种子组织的酵母双杂交cDNA文库,获得了38个TTG1阳性互作蛋白,首次挖掘到了可能影响白菜种皮颜色原花青素形成的R2R3-MYB型抑制子MYB73,为后期探究白菜种皮原花青素的调控网络奠定良好的基础。

Bioinformatics and Expression Pattern Analysis of Tomato ns LTP 2-like cDNA full-length Gene Clone

TDF1(transcription-drived fragment) was homologous to the predicted S. lycopersicum nonspecific lipid-transfer protein,nsLTP 2-like(91%), and it was significantly upregulated in response to C. fulvum(cladosporium fulvum) infection in tomato plants.In this experiment, the full-length cDNA of nsLTP 2-like was cloned using RACE technology based on the sequence of TDF1(GenBank: JZ717725). A full-length, 625 bp(GenBank: KU366289), cDNA sequence, which with 98% similarity to nsLTP 2-like gene(GenBank: XM015233692) was obtained. This cDNA contains an ORF(open reading frame) with full-length of 345 bp, coding of 114 amino acids, including 12.3% Ala and Gly. Protein molecular weight was 11.51 ku, the isoelectric point(pI) was 8.99, and average overall hydrophilicity was 0.412, with one phosphorylation sites, belonging to volatile acidic nuclear protein. Secondary structure prediction showed that α-Helix accounts for 30.7%, extension chain for 12.28%, β-corner for 9.65%, and random coil for 47.37%. Through comparative analysis of the homology among species, it was found that the amino acid sequence of tomato nsLTP 2-like protein had a high similarity with other plants, and with a specific conserved sequence which might related features in nsLTP 2-like protein. It also be analyzed the gene expression pattern of tomato in different parts and under different stress conditions.The results showed that nsLTP 2-like gene was up-regulated in varying degrees, under the condition of cold stress, exogenous hormone spraying and cladosporium fulvum infection. Therefore, it was speculated that the gene played a role in response to abiotic and biotic stress in tomato.

SCREENING A CDNA LIBRARY FOR PHOSPHOLIPASE A2 CLONES USING BLOOD AGAR PLATES

A technique was developed for detecting venom phospholipase A2(PLA2) using serum and red blood cells. M1 and M2, two PLA2s isolated from Crotalus m.molossus (Northern black-tail rattlesnake), were used for preliminary development of the as say. Various combinations of human, sheep, rat, and mouse red blood cells (RBC) with human,rat,and mouse sera were tested on their effectiveness to detect PLA2.Complete hemolysis (b hemolysis) was evident in the plate with rat RBC mixed with mouse serum.No hemolysis was detected in plates containing human RBC and human serum. Human RBC mixed with mouse serum proved to be ideal, even though this combination displayed incomplete hemolysis(a hemolysis).Susceptible RBC, in conjunction with rat or mouse serum, are excellent indicators for the presence of PLA2.Mixtures of RBC and serum in combination with BB4(E. coli) cells,λbacteriophage,and IPTG on LB agar plates provide an excellent detection system for cDNA clones that express venonl PLA2. Hemolysis surrounding a plaque is identified as positive for PLA2.

矢车菊不同颜色花瓣酵母cDNA文库的构建

【目的】矢车菊花瓣的蓝色呈色和品种间花色变异的分子调控机制尚不明晰。本研究采用Gateway技术构建了矢车菊6个不同花色品种花瓣的酵母cDNA文库,以期进一步通过酵母单杂交或双杂交技术筛选参与调控花瓣呈色的关键互作蛋白。【方法】本研究以白色、粉色、红色、蓝色、紫色和墨色矢车菊花瓣为材料,提取总RNA后分离和纯化mRNA,合成双链cDNA后依次进行BP重组反应和LR重组反应,分别获得初级和次级文库。最后将次级文库质粒转化酵母Y187,获得矢车菊不同颜色花瓣的酵母cDNA文库。【结果】质量鉴定结果显示:初级文库的库容量为1.3×10^(7) CFU,重组率为100%,且插入片段长度均在1000 bp以上;次级文库的库容量为1.6×10^(7) CFU,重组率为100%,且插入片段长度均在1000 bp以上。酵母文库的滴度为3.5×10^(7) CFU/mL,随机挑选的24个单克隆经PCR检测后均扩增出明亮条带,重组率为100%,插入片段长度均大于1000 bp。【结论】本研究构建的矢车菊不同颜色花瓣酵母cDNA文库的质量较高,能满足酵母文库筛选的试验要求,为后续探究矢车菊花瓣的蓝色呈色和品种间花色变异的分子调控机制提供了材料基础。

橡胶树棒孢霉落叶病菌酵母单杂交cDNA文库及CcCas5启动子诱饵载体的构建

为了筛选出与CcCas5启动子结合的转录因子,本研究构建了橡胶树棒孢霉落叶病菌的酵母单杂交cDNA表达文库和CcCas5启动子诱饵载体,并对3-氨基-1,2,4-三唑(3-amino-1,2,4-triazole,3-AT)的最佳抑制浓度进行了筛选。结果显示,构建的酵母单杂交cDNA表达文库总容量为3.49×10^(6)cfu,插入片段主要分布于750~2000 bp之间,重组率为95.8%;克隆了CcCas 5基因2600 bp的启动子序列,预测获得真菌主要的10大类转录因子的结合位点165个;构建了分别携带1500 bp和1000 bp启动子序列的酵母单杂交启动子诱饵载体,10 mmol/L的3-AT能抑制pHis2.1-pCcCas5-1000和pHis2.1-pCcCas5-1500的背景表达。试验结果为通过酵母单杂交筛选与CcCas5启动子结合的转录因子和进一步研究转录因子对CcCas5表达的调控作用奠定基础。

Construction of Larval cDNA Expression Library and Immunological Identification of Positive Clones in Tick Haemaphysalis qinghaiensis

A primary cDNA expression library with a titer of 5.0 × 105 PFU mL-1 was constructed from mRNA extracted from larval Haemaphysalis qinghaiensis ticks in order to identify certain genes,which would then be used as candidate molecules for development of effective vaccines to control this parasite.Totally 11 positive clones,which designated as HqL01-11,were obtained by immunoscreening of the library using a polyclonal antibody generated in rabbit with larval tick protein extract.Results of sequence analysis from BLASTN searching revealed that 6 of them had no significant homology with the adult H.qinghaiensis ticks’ known genes,4 of them had no significant homology with all genes deposited in GenBank database.HqL07,HqL08,HqL09,and HqL11 were deposited to GenBank database,and accession numbers were EF605263,EF605264,EF605265,and EF605266,respectively.Subsequently,HqL07 and HqL09 were expressed in vitro and the molecular weights of the corresponding expressed products were 60 and 70 kDa,respectively.Western blot analyses showed that HqL07 and HqL09 had immunogenicity.This study laid the foundation for future production of genetically engineered vaccines for the immunological control of H.qinghaiensis.

灰霉菌胁迫下番茄叶片cDNA文库构建及SlbZIP1互作蛋白筛选鉴定

为筛选番茄在灰霉菌侵染下与bZIP转录因子SlbZIP1(Solyc01g008730.2.1)互作的蛋白,以感病番茄Moneymaker为材料,提取接种灰霉菌胁迫处理后0、24、48、72、96 h的番茄叶片的总RNA,通过三框法构建cDNA酵母文库,计算文库库容量、重组效率。同时,以SlbZIP1为诱饵,利用构建的文库探索其在灰霉菌侵染过程中的互作蛋白,并对其中可能参与病原菌防御反应的潜在蛋白在酵母中进行互作验证。结果表明,酵母文库库容达到1.5×10^(6)CFU,重组效率为98%。酵母双杂交共计筛选到14个与SlbZIP1互作的潜在蛋白。进一步互作验证表明,SlbZIP1与谷氧还蛋白SlGRXC9、SlGRXC6、bZIP转录因子SlTGA2.2及钙调蛋白SlCaM1均存在互作。上述结果可为进一步阐明SlbZIP1对腐生型真菌病害的抗病分子机制奠定基础。

HP8: The cDNA clone of a novel member of C/EBP gene family

We obtained a positive clone by screening human fetal liver cDNA library with rat C/EBP cDNA probe.The clone , designated HPS , contains 2480 base pairs , 1026 of which are coding base pairs (from No. 84 to 1109).No homologous DNA sequence is found in the Gene Database (EMBL 95. 6) . The 341 amino acids encoded by HPS gene contained the leucine zipper structure at the Cterminal. They presented a high degree of homology (97%) to CIEBP throughout the DNA-binding domain and leucine repeat region(C-terminal 60 amino acids) , but in the upstream coding region , only a low degree of homology was detected to C/EBP or its related proteins , suggesting HPS is a novel member of CIEBP gene family. Southern blot analysis confirmed that HP8 gene was a single copy gene. Northern blot analysis of 14 different fetus tissues showed that HPS gene registered a high level expression in small intestine and skin , a middle level expression in adrenal ,a low level expression in liver , lung , kidney ,thyroid gland and gallbladder. Of 5 normal human adult liver tissues , only two were found to have low level HP8expression , whereas in 13 hepatoma and its surrounding nontumorous hepatic tissues , high level of HPS expression was detected in 9 hepatomas and 7 surrounding nontumorous hepatic tissues. These results suggest that HP8 gene may be a transactivator related to cell growth. A deeper research of its functions is now in progress.

CloneIRD:面向代码溯源的克隆代码继承关系判定方法

随着开源软件的广泛使用,代码溯源成为管理软件源代码、降低潜在风险的重要技术手段。基于代码克隆检测的大规模代码溯源分析,从其检测结果中鉴别代码克隆对之间的继承关系,对代码来源追踪、组件依赖关系分析、软件脆弱性分析以及代码缺陷修复等具有重要意义。目前,已有方法在原始代码片段存在微小修改的情况下,会产生许多误判,并且检测克隆对的效率也有待提高。针对上述问题,提出了代码溯源中克隆代码继承关系的判定方法CloneIRD,包括一个基于自研快速分布式克隆检测工具FastDCF的代码溯源分析框架,以及该框架的核心算法——基于代码演化信息的克隆代码继承关系判定算法EIHR。为验证框架和算法的有效性,首先设计并实现了CloneIRD方法,并在Linux内核V4.9和V4.12的开源代码上进行了实验。实验结果表明,CloneIRD方法能够有效判定代码溯源结果中克隆对的继承关系,且基于FastDCF的溯源分析框架能够胜任大规模代码的溯源分析任务。

EFFECTS OF A SYNTHETIC POLYPEPTIDE ENCODED BY THE p14-6,A cDNA CLONE WITH ANTIONCOGENE ACTIVITY, ON MALIGNANT TRANSFORMED DT CELLS

A synthetic polypeptide, pt27, which is encoded by a cDNA clone with antloncogene activity, p14-6, is found to be able to reduce remarkably the soft agar colony formation ability of part of DT cells and to raise their resistance to the ouabaln toxtcity. This shows that the pt27 peptide can affect the DT cells In a manner similar to the p14- 6 done and provides evidence that the reverting action of the p14-6 to DT cells may be exerted by the expression of its cDNA.

Isolating cDNA clones from rice induced by Magnaporthe grisea using PCR based differential screening method

The differential hybridization technique hasbeen widely used to identify genes that are dif-ferentially expressed.However,this approachhas several drawbacks.First,the screeningprocedures are rather labor-intensive and time-consuming.Second,the amount of phageDNAs transferred onto the two filters may notbe equivalent,which leads to an inaccurate se-lection of a positive clone.Third,isolation ofphage DNA is slow and cumbersome.Here,aPCR based differential screening method that

麦根腐平脐蠕孢cDNA文库的构建及BsTup1互作蛋白筛选

【目的】深入探究麦根腐平脐蠕孢(Bipolaris sorokiniana)生长发育及致病力的分子作用机制,并鉴定BsTup1的互作蛋白。【方法】利用麦根腐平脐蠕孢(B.sorokiniana)孢子和不同时期的菌丝体为材料,构建酵母双杂交cDNA文库,以BsTup1基因为诱饵来筛选酵母双杂交文库,确定与BsTup1相互作用的蛋白。【结果】1)利用SMART(switching mechanism at 5′end of the RNA transcript)技术首次成功构建了麦根腐平脐蠕孢(B.sorokini-ana)分生孢子和菌丝体的混合cDNA文库。文库鉴定结果表明,构建的cDNA文库库容为4.8×10^(7) cfu·mL^(-1),文库插入片段重组率达100%且平均大小为1000 bp。2)构建了pGBKT7-BsTup1诱饵载体,无自激活活性。3)使用诱饵蛋白载体pGBKT7-BsTup1对麦根腐平脐蠕孢(B.sorokiniana)酵母双杂交cDNA文库进行筛选,经测序、序列比对和酵母回转验证,获得38个与BsTup1相互作用的候选蛋白。【结论】成功构建了麦根腐平脐蠕孢(B.sorokiniana)的cDNA文库,并鉴定出38个与BsTup1相互作用的候选蛋白。

基于真核CMV启动子构建猪瘟病毒感染性cDNA克隆与病毒拯救

为建立猪瘟病毒(CSFV)反向遗传操作系统,本研究将CSFV石门株(SM)全基因组克隆至pBAC11载体中,并采用重叠延伸PCR方法在病毒基因组5'端和3'端分别加入CMV真核启动子序列和RzBGH序列,并将其基因组nt2809的碱基C突变为T,将原有的AfeⅠ酶切位点突变消失作为拯救病毒的遗传标记。将构建的质粒转染PK-15细胞培养后,收集细胞上清盲传3代后通过RT-PCR扩增蛋白编码基因,并经间接免疫荧光试验(IFA)鉴定。RT-PCR鉴定结果显示扩增到CSFV特异性基因;IFA结果显示接种病毒的细胞出现绿色荧光。表明病毒拯救成功,将其命名为BAC-rSM。将BAC-rSM株在PK-15细胞中连续传18代,将第18代病毒经RT-PCR扩增E2基因,并对遗传标记的位点经Afe I酶切和鉴定,分析BAC-rSM病毒的遗传稳定性,结果显示第18代BAC-rSM株遗传标记稳定存在,表明拯救的病毒具有遗传稳定性。将BAC-rSM和SM株病毒分别以MOI 1感染PK-15细胞,在感染后不同时间点收获病毒并测定病毒滴度,结果显示BAC-rSM和SM株生长动力学特征基本一致。对第18代BAC-rSM株与SM株进行全基因组序列比对分析,利用在线软件npsa-prabi.ibcp.fr/对Erns和E2蛋白二级结构预测,采用荧光定量PCR(qPCR)对BAC-rSM和SM株感染PK-15细胞中IFN-βmRNA的转录水平。全基因测序比对分析结果显示,BAC-rSM株基因组共存在46个碱基突变,经预测其Erns和E2的突变导致各自的二级结构改变;qPCR检测结果显示,相对SM感染的PK-15细胞,BAC-rSM感染后8 h和24 h PK-15细胞中IFN-βmRNA的转录水平显著或极显著降低(P<0.05、P<0.01)。本研究建立了一种简单、操作方便的CSFV反向遗传操作系统的方法,为进一步开展CSFV的分子生物学、毒力决定因素、分子发病机制、疫苗开发和病毒与宿主相互作用的研究提供了新的技术方法。

cDNA文库的构建及其在兽医研究中的应用

cDNA文库是一个包含特定组织或细胞类型全套基因表达信息的克隆集合,是进行基因表达分析和功能研究的重要工具。构建高质量的cDNA文库对于捕获全面的转录信息至关重要,这涉及样本的选择、处理、cDNA的合成和文库的构建等一系列步骤的优化。该文介绍了cDNA文库的概念、构建技术及其在兽医学中的应用,并对技术进展和未来的研究方向进行了展望。