6 resultados para RAP

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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The optical constants of two cyanine dye films that we prepared were measured with a RAP-1-type (RAP is rotating analyzer and polarizer) spectroscopic ellipsometer. Toward making a simplified model for the wafers of a recordable compact disk (CD-R), we give their optimization designs developed with the cyanine dye films. in addition, the dynamic storage performances of two sample disks were tested by our dynamic storage testing system. Measurement results of the sample disks were obtained to test and verify our film designs. (C) 2000 Optical Society of America. OCIS codes: 160.4890, 160.4760, 210.4810.

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Pituitary growth hormone (GH), like several other protein hormones, shows an unusual episodic pattern of molecular evolution in which sustained bursts of rapid change are imposed on long periods of very slow evolution (near-stasis). A marked period of rap

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Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is one of the TNF superfamily members, participating in many biological processes including cell proliferation and apoptotic death. In this study, a TRAIL gene was cloned from a perciform fish, the mandarin fish Siniperca chuatsi, a major cultured fish in China's aquaculture, and is named as SCTRAIL for S. chuatsi TRAIL. The full-length cDNA of SCTRAIL is 1359 bp, encoding a 283-amino-acid protein. This deduced protein contains the CYS231, a 23-mer fragment of transmembrane region, a glycosylation site and a TNF family signature, all of which are conserved among TRAIL members. SCTRAIL gene consists of six exons, with five intervening introns, spaced over approximately 9 kb of genomic sequence. Southern blotting demonstrated that the SCTRAIL gene is present as a single copy in mandarin fish genome. A 620 bp promoter region obtained by genome walking contains a number of putative transcription factor binding sites, such as Oct-1, Sp-1, NF-1, RAP-1, C/EBPaLp, NF-kappa B and AP-1. The SCTRAIL is constitutively expressed in all the analyzed tissues, as revealed by RT-PCR, which is confirmed by Western blotting analysis using polyclonal antibody against bacteria-derived recombinant SCTRAIL protein. As an apoptosis-inducing ligand, the overexpression of SCTRAIL but not the mutant SCTRAIL-C203S in HeLa cells induced changes characteristic of apoptosis, including chromatin condensation, nucleus fragmentation, DNA ladder, and increase of sub-G0/G1 cells in FACS analysis. (c) 2007 Elsevier Ltd. All rights reserved.

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本实验室果蝇研究工作,主要集中在黑腹果蝇的新基因起源的研究。新基因起源的分子机制主要包括:外显子重排、基因复制、基因逆转座、移动元件介导、基因水平转移、基因从头起源、基因的断裂融合。为了阐述这些新基因的产生和它们所带来的物种适应性,我们对这些新近起源的基因进行了功能研究。但是,仅仅限于新基因所在物种的功能研究并不能完全解释新基因产生的进化原因,我们需要了解它是否能够给没有该基因的果蝇物种带来一定的适应性。例如一些生殖相关新基因,如果我们将它们转入没有该基因的果蝇,那是否能够给该果蝇带来生殖能力的提高?无论结果如何,这都为我们研究新基因的起源提供一个重要线索。由此,黑腹果蝇以外的其它果蝇物种中实现转基因成为该研究的重要技术环节。但是,实验室目前的转基因系统仅限于P转座子介导的黑腹果蝇转基因系统,因而我们需要建立一种新的转基因平台。而转座子Minos打破物种范围的转基因特性,以及它的转座特点为我们提供了选择。转座子Minos是从果蝇D. hydei中克隆出来长约1.8kb的Ⅱ型转座子,Tc1家族转座元件成员。Minos的转座机制与大部分转座子一样,在宿主基因组里面实行着剪切和粘贴的运作机制。Minos在转座时,偏向插入TA位点并且主要集中于内含子区域,这样可以减少对插入位置基因的影响。此外,Minos在黑腹果蝇中的转座效率约30%,并且拥有一套成熟的选择标记。因此,Minos成为我们解决非黑腹果蝇转基因技术难题的首选。 在本文的工作中,我们采用由希腊Savakis教授(希腊分子生物学与生物技术研究所)提供的Minos转基因系统,完成果蝇的转基因实验。在这套转基因系统中,非自主的转座子Minos和转座酶基因被克隆到了不同载体当中。其中Minos转座子序列中插入了由3xP3眼睛特异表达的启动子介导表达的eGFP报告基因,而转座酶基因则由热激蛋白hsp70启动子调控表达。实验过程中,我们在果蝇D. melanogaster 和D. yakuba的胚胎中分别同时显微注射入含有转座子和转座酶本实验室果蝇研究工作,主要集中在黑腹果蝇的新基因起源的研究。新基因起源的分子机制主要包括:外显子重排、基因复制、基因逆转座、移动元件介导、基因水平转移、基因从头起源、基因的断裂融合。为了阐述这些新基因的产生和它们所带来的物种适应性,我们对这些新近起源的基因进行了功能研究。但是,仅仅限于新基因所在物种的功能研究并不能完全解释新基因产生的进化原因,我们需要了解它是否能够给没有该基因的果蝇物种带来一定的适应性。例如一些生殖相关新基因,如果我们将它们转入没有该基因的果蝇,那是否能够给该果蝇带来生殖能力的提高?无论结果如何,这都为我们研究新基因的起源提供一个重要线索。由此,黑腹果蝇以外的其它果蝇物种中实现转基因成为该研究的重要技术环节。但是,实验室目前的转基因系统仅限于P转座子介导的黑腹果蝇转基因系统,因而我们需要建立一种新的转基因平台。而转座子Minos打破物种范围的转基因特性,以及它的转座特点为我们提供了选择。转座子Minos是从果蝇D. hydei中克隆出来长约1.8kb的Ⅱ型转座子,Tc1家族转座元件成员。Minos的转座机制与大部分转座子一样,在宿主基因组里面实行着剪切和粘贴的运作机制。Minos在转座时,偏向插入TA位点并且主要集中于内含子区域,这样可以减少对插入位置基因的影响。此外,Minos在黑腹果蝇中的转座效率约30%,并且拥有一套成熟的选择标记。因此,Minos成为我们解决非黑腹果蝇转基因技术难题的首选。 在本文的工作中,我们采用由希腊Savakis教授(希腊分子生物学与生物技术研究所)提供的Minos转基因系统,完成果蝇的转基因实验。在这套转基因系统中,非自主的转座子Minos和转座酶基因被克隆到了不同载体当中。其中Minos转座子序列中插入了由3xP3眼睛特异表达的启动子介导表达的eGFP报告基因,而转座酶基因则由热激蛋白hsp70启动子调控表达。实验过程中,我们在果蝇D. melanogaster 和D. yakuba的胚胎中分别同时显微注射入含有转座子和转座酶所在的质粒。转座酶在37度条件诱导下进行表达,协助Minos完成转座过程。在转基因果蝇的阳性筛选中,我们利用眼睛特异表达的绿色荧光蛋作为选择标记。并且,我们通过PCR实验进一步验证了转基因果蝇的真实性。本研究中,我们对转基因实验条件进行了初步优化。我们通过对黑腹果蝇白眼突变品系W1118和D. yakuba注射后胚胎进行保湿,对D. yakuba注射胚胎进行非退壳处理。在改进条件下W1118和D. yakuba的存活率分别为10%和3%左右。通过筛选转基因阳性果蝇,我们得出Minos在W1118和D. yakuba中的转座效率分别在32%和20%左右。我们的实验结果再一次证实了Minos在果蝇D. melanogaster中可行性。同时,该工作也初步完成了在果蝇D. yakuba 中的第一次Minos介导的转基因实验,为新基因的跨物种功能研究奠定了实验基础。在未来的工作计划中,我们将采用Minos转基因系统,把实验室目前研究的黑腹果蝇新基因导入其它物种果蝇进行功能研究。 水稻是一种重要的世界粮食作物,世界上过半的人口以水稻为主食。水稻相对别的粮食作物来讲具有较小的基因组,并且拥有较好的基因组注释,是一种理想的单子叶模式生物。植物转基因技术的发展推动着水稻功能基因组学的研究,目前水稻的转基因技术主要依赖于土壤细菌农杆菌(Agrobacterium tumefaciens)T-DNA介导的外源基因染色体插入。在自然状态下,农杆菌的T-DNA位于Ti致瘤质粒当中。它包括了一些转座元件和一些帮助T-DNA转座的毒性蛋白基因和调节基因。由于Ti质粒上的T-DNA太长,并且没有太多的酶切位点,因此自然状态的T-DNA不适合进行转基因实验。为了方便T-DNA的实际应用,研究人员创立了双载体转基因系统。T-DNA转座区被分离到出Ti载体,并且装载到另外一个适合实验操作的质粒当中,而毒性蛋白表达基因等则保留在Ti质粒上。因此,在进行T-DNA介导的转基因实验时,需要同时存在T-DNA载体和Ti质粒。 本文以“水稻注释计划数据库RAP-DB”的表达数据为参考,选择了60个高表达基因的启动子区域进行克隆。通过对T-DNA载体pCAMBIA1301 进行改造,去掉其原来的35S启动子,将预测的基因启动子克隆到该载体中并与报告基 摘要 因GUS 基因融合。通过分子克隆实验,我们得到了45个高表达基因的启动子载体。最终,为了测试这45个启动子的启动效率,我们会将它们转化到水稻愈伤组织中通过启动子融合的GUS基于表达情况来判断我们启动子的启动效率。

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禾谷孢囊线虫严重影响禾谷类作物的产量,在小麦中由禾谷孢囊线虫引起的产量损失可达30-100%。尤其在澳大利亚、欧洲、印度和中东危害严重,目前禾谷孢囊线虫已成为危害我国作物的主要病源。控制禾谷孢囊线虫的方法主要有:作物轮作、杀线虫剂、寄主抗性等等,其中基因工程方法培育抗线虫小麦品种被认为是最经济有效的方法。分离抗禾谷类孢囊线虫基因对揭示抗性基因结构与功能及其表达调控具有重要意义。 尽管小麦是重要的粮食作物,在小麦中已发现的抗禾谷孢囊线虫的基因很少,而比其近缘属如节节麦、易变山羊草、偏凸山羊草中含有丰富的抗源。目前已鉴定出禾谷孢囊线虫抗性位点Cre,并发现了9个禾谷孢囊线虫抗性基因(Cre1,2, 3, 4, 5, 6, 7, 8, and R) ,其中只有Cre1和Cre8直接从普通小麦中获得。从节节麦中获得的Cre3基因能最有效的控制线虫数量,其次是Cre1和Cre8。这些基因的克隆对于了解禾谷孢囊线虫抗性机制及进一步的育种应用都是非常关键的。然而,目前为止仅有Cre3基因通过图位克隆的方法从节节麦中被分离得到。该基因已被克隆得到的多数线虫抗性基因一样均属于核苷酸结合位点区(NBS)-亮氨酸重复序列区(LRR)基因家族。目前,已有很多抗性基因被分离,这些已知的NBS-LRR类抗性基因的保守序列为应用PCR的方法克隆新的抗性基因提供了可能。 因此本课题的目的是采用保守区同源克隆、3′RACE 和5′RACE 等方法从抗禾谷孢囊线虫小麦-易变山羊草小片段易位系E10 中克隆小麦抗禾谷孢囊线虫基因全序列,进而通过半定量PCR 和荧光定量PCR 研究该基因的表达模式。同时通过mRNA 差别显示技术和任意引物PCR(RAP-PCR)技术分离克隆植物禾谷孢囊线虫抗性基因及其相关基因,为阐明植物抗病性分子机制以及改良作物抗病性和作物育种提供基础,为通过分子标记辅助育种和基因工程方法实现高效、定向转移抗病基因到优良小麦品种奠定了重要的理论和物质基础。主要研究结果: 1. 本实验根据此前从抗禾谷孢囊线虫材料E-10 扩增得到的与来自节节麦的抗禾谷孢囊线虫Cre3 基因及其他的NBS-LRR 类抗性基因的NBS 和LRR 保守区序列设计了两对特异性引物,从E10 中扩增到532bp 和1175bp 的两个目标条带,它们有一个32bp 的共同序列,连接构成总长为1675bp 的NBS-LRR 编码区(命名为RCCN)。根据RCCN设计引物,利用NBS-LRR区序列设计引物,通过5′RACE 和3′RACE 技术采用3′-Full RACE Core Set(TaKaRa)和5'-Full RACE Kit (TaKaRa)试剂盒,反转录后通过嵌套引物GSP1 和GSP2 分别进行两轮基因特异性扩增,分别将NBS_LRR 区向5′端和3′端延伸了1173bp 和449bp,并包含了起始密码子和终止密码子。根据拼接的得到的序列重新设计引物扩增进行全基因扩增的结果与上面获得的一致。拼接后得到全长2775 bp 的基因序列(记作CreZ, GenBank 号:EU327996)。CreZ 基因包括完整的开放阅读框,全长2775 bp,编码924个氨基酸。序列分析表明它与已知的禾谷孢囊线虫抗性基因Cre3的一致性很高,并且它与已经报到的NBS-LRR 类疾病抗性基因有着相同的保守结构域。推测CreZ基因可能是一个新的NBS-LRR 类禾谷孢囊线虫抗性基因,该基因的获得为通过基因工程途径培育抗禾谷孢囊线虫小麦新品种奠定了基础,并为抗禾谷孢囊线虫基因的调控表达研究提供了参考。 2. 通过半定量PCR和SYBR Green荧光定量PCR技术对CreZ基因的相对表达模式进行了研究。以α-tubulin 2作为参照,采用半定量PCR 分析CreZ 基因在不同接种时期1d, 5d, 10, 15d 的E-10的根和叶的的表达情况。在内参扩增一致的条件下,CreZ 在E-10的根部随着侵染时间的增加表达量有明显的增加,在没有侵染的E-10的根部其表达量没有明显变化,而在叶中没有检测表达,说明该基因只在抗性材料的根部表达。SYBR Green定量PCR分析接种前后E10根部基因CreZ基因的表达水平为检测CreZ基因的表达建立了一套灵敏、可靠的SYBRGreen I 荧光定量PCR 检测方法。接种禾谷孢囊线虫后E10根内CreZ基因的相对表达水平显著高于接种前。随接种时间的延长持续增加,最终CreZ基因的相对表达量达到未接种的对照植株的10.95倍。小麦禾谷孢囊线虫抗性基因CreZ的表达量与胁迫呈正相关,表明其与小麦的的禾谷孢囊线虫抗性密切相关,推测CreZ基因可能是一个新的禾谷孢囊线虫候选抗性基因。 3. 针对小麦基因组庞大、重复序列较多,禾谷孢囊线虫抗性基因及其相关基因的片断难以有效克隆的问题,通过mRNA 差别显示技术及RAP-PCR 技术分离克隆植物禾谷孢囊线虫抗性及其相关基因。试验最终得到154 条差异表达条带,将回收得到的差异条带的二次PCR 扩增产物经纯化后点到带正电的尼龙膜上,进行反向Northern 杂交筛选,最终筛选得到102 个阳性差异点。将其中81 个进行测序,并将序列提交到Genbank 中的dbEST 数据库,分别获得登录号(FE192210 -FE192265,FE193048- FE193074 )。序列比对分析发现,其中26 个序列与已知功能的基因序列同源;有28 条EST 序列在已有核酸数据库中未找到同源已知基因和EST,属新的ESTs 序列;另外27 个EST 序列与已知核酸数据库中的ESTs 具有一定相似性,但功能未知。其所得ESTs 序列补充了Genbank ESTs 数据库,为今后进一步开展抗禾谷类孢囊线虫基因研究工作打下了基础。结合本试验功能基因的相关信息,对小麦接种禾谷孢囊线虫后产生的抗性机制进行了探讨。接种禾谷孢囊线虫后植物在mRNA 水平上的应答是相当复杂的,同时植物的抗病机制是一个复杂的过程,涉及到多个代谢途径的相互作用。 The cereal cyst nematode (CCN), Heterodera avenae Woll, causes severe yieldreductions in cereal crops. The losses caused by CCN can be up to 30-100% in somewheat fields. At present, cereal cyst nematode has become the major disease sourcein China and it also damaged heavily in Australia, Europe, India and Middle East.The damage caused by CCN can be mitigated through several methods, includingcrop rotation, nematicide application, cultural practice, host resistance, and others.Of these methods, incorporating resistance genes into wheat cultivars and breedingresistant lines is considered to be the most cost-effective control measure forreducing nematode populations. Although wheat is an economically important crop around the world, far fewergenes resistant to CCN were found in wheat than were detected in its relatives, suchas Aegilops taucchi, Aegilops variabilis and Aegilops ventricosa. Cloning these genesis essential for understanding the mechanism of this resistance and for furtherapplication in breeding. Because of the huge genome and high repeat sequencescontent, the efficient methods to clone genes from cereal crops, are still lacking. A resistance locus, Cre, has been identified and 9 genes resistant to CCN (designatedCre1, 2, 3, 4, 5, 6, 7, 8, and R) have been described, in which Cre1 and Cre8 werederived directly from common wheat. The Cre3 locus, which was derived from Ae.tauschii, has the greatest impact on reducing the number of female cysts, followed byCre1 and Cre8. Cloning these genes is essential for understanding the mechanism ofthis resistance and for further application in breeding. However, to this point, only Cre3, a NBS-LRR disease resistance gene, has been obtained through mappingcloning in Ae. tauschii. The majority of nematode resistance genes cloned so far belong to a super familywhich contains highly conserved nucleotide-binding sites (NBS) and leucine-richrepeat (LRR) domains. To date, many NBS-LRR resistance genes have been isolated.The conserved sequences of these recognized NBS-LRR resistance genes provide thepossibility to isolate novel resistance genes using a PCR-based strategy. The aim of the present study was to clone the resistance gene of CCN fromWheat/Aegilops variabilis small fragment chromosome translocation line E10 whichis resistant to CCN and investigate the espression profiles of this gene withsemi-quantitative PCR and real-time PCR. Another purpose of this study is cloningthe relational resistance gene for CCN by mRNA differential display PCR andRAP-PCR. These works will offer a foundation for disease defence of crop andbreeding and directional transferring resistance gene into wheat with geneengineering. Primary results as following: 1.According to the conversed motif of NBS and LRR region of cereal cystnematode resistance gene Cre3 from wild wheat (Triticum tauschlii) and the knownNBS-LRR group resistance genes, we designed two pairs of specific primers for NBSand LRR region respectively. One band of approximately 530bp was amplified usingthe specific primers for conversed NBS region and one band of approximately 1175bpwas amplified with the specific primers for conversed LRR region. After sequencing,we found that these two sequences included 32bp common nucleotide having 1675bpin total, which was registered as RCCN in the Genbank. Based on the conservedregions of known resistance genes, a NBS-LRR type CCN resistance gene analog wasisolated from the CCN resistant line E-10 of the wheat near isogenic lines (NILs), by5′RACE and 3′ RACE.designated as CreZ (GenBank accession number: EU327996) .It contained a comlete ORF of 2775 bp and encoded 924 amino acids. Sequencecomparison indicated that it shared 92% nucleotide and 87% amino acid identitieswith those of the known CCN-resistance gene Cre3 and it had the same characteristic of the conserved motifs as other established NBS-LRR disease resistance genes. 2. Usingα-tubulin 2 as exoteric reference, semi-quantitative PCR and real-timePCR analysis were conducted. The expression profiling of CreZ indicated that it wasspecifically expressed in the roots of resistant plants and its relative expression levelincreased sharply when the plants were inoculated with cereal cyst nematodes. therelative expression level of the 15days-infected E10 is the 10.95 times as that ofuninfected E10,ultimately. It was inferred that the CreZ gene be a novel potentialresistance gene to CCN. 3.We cloned the relational resistance gene for CCN by mRNA differentialdisplay PCR and arbitrarily primed PCR fingerprinting of RNA from wheat whichpossess huge and high repeat sequence content genomes. Total 154 differentialexpression bands were separated and second amplified by PCR. The products werenylon membrane. The 102 positive clones were filtrated by reverse northern dot blotand 81 of those were sent to sequence. The EST sequences were submitted toGenbank (Genbank accession: FE192210 - FE192265, FE193048 - FE193074). Thesequences alignment analysis indicated 26 of them were identical with known genes;28 were not found identical sequence in nucleic acid database; another 27 ests wereidentical with some known ests, but their functions were not clear. These ESTsenriched Genbank ESTs database and offered foundation for further research ofresistance gene of CCN.

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To understand the molecular events of ovarian development in penaeid shrimp, RNA arbitrarily primed polymerase chain reaction (RAP-PCR) was used to identify differentially expressed genes during ovarian maturation in Metapenaeus ensis. From a screening of 700 clones in a cDNA library of the shrimp ovary by the products of RAP-PCR of different maturation stages, 91 fragments with differentially expressed pattern as revealed by dot-blot hybridization were isolated and sequenced. Forty-two of these fragments show significant sequence similarity to known gene products and the differentially expressed pattern of 10 putative genes were further characterized via Northern hybridization. Putative glyceraldehyde-3-phosphate dehydrogenase and arginine kinase are related to provision of energy for active cellular function in oocyte development. Translationally controlled tumor protein, actin, and keratin are related to the organization of cytoskeleton to accomplish growth and development of oocytes. High mobility group protein DSP1, heat shock protein 70, and nucleoside diphosphate kinase may act as repressors before the onset of ovarian maturation. Peptidyl-prolyl cis-trans isomerase and glutathione peroxidase are related to the stabilization of proteins and oocytes. This study provides new insights on the molecular events in the ovarian development in the shrimp.