168 resultados para RNA, Ribosomal, 16S


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植物激素乙烯作为一种信使分子调节控制果实完熟。ACC合成酶是植物体内乙烯生物合成途径的限速酶,其反义RNA的表达将能有效地抑制乙烯的生物合成而延缓果实完熟,利用反转录PCR技术克隆获得了ACC合成酶多基因家族成员之一LE-ACC2阅读框架约1.7kb的cDNA,经酶切图谱和序列分析鉴定无误后,反向连入植物表达载体pBin437中构建成组成型表达ACC合成酶反义RNA的双元载体。经农杆菌途径转化番茄“丽春”品种,获得了60株抗卡那再生杭株,PCR检测证明有6株为转基因植株,Southern杂交和Northern杂交分析进一步确证了外源基因的插入及其转录活性。反义番茄果实的乙烯释放受到明显抑制,表现出更好的耐储保鲜特性,并且与对照相比,在果实品质上没有明显差别。大田培育Fl和F2代转化番茄植株,反义番茄纯合品系的筛选工作正在进行之中。 同时,本研究利用已经获得的ACC合成酶和PG的cDNA克隆,构建了两个嵌合转化基因载体pPGACC1、pPGACC10,它包括1300bp的ACC合成酶cDNA编码序列,并分别含有反向与正向的250bp的5’端PG基因片断。酶切图谱和序列分析鉴定无误后,以pBin437为植物表达载体构建了双元载体pBPGACC1和pBPGACC10,分别表达PG正义RNA和反义RNA,并均表达ACC合成酶反义RNA。经农杆菌转化番茄子叶,植株的再生培育有待进行。通过对转基因植物的分析,我们期望阐明用单一嵌合基因表达载体通过反义抑制与抑制作用实现对内源两同源基因——PG和ACC合成酶下降调节的可能性,并可望得到具有更好耐储效果且品质优良的番茄品系。

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本发明公开了金丝桃素的新用途。本发明发明人的实验证实,金丝桃素对RNA病毒,特别是禽流感病毒,口蹄疫病毒和犬瘟热病毒具有较好的抑制和灭活效果,可以该化合物为活性成分,制备成抗RNA病毒药物。该抗病毒药物可用于临床防治和治疗禽流感、犬瘟热、口蹄疫等由RNA病毒引发的疾病,对禽业、犬业及畜牧养殖业等意义重大。此外,我国草药资源丰富,该药物具有工业化生产的可行性。综上所述,金丝桃素将在医学和生物制药领域,尤其是抗RNA病毒药物的制备领域具有较大的实际意义和广阔的应用前景。

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从广西产眼镜王蛇( Ophiophagus hannah) 毒腺中抽提总RNA , 经mRNA 纯化后构建眼镜王蛇毒腺 cDNA 文库。从所构建的cDNA 文库中, 随机筛选200 个克隆测序, 得到两个在进化上高度保守的基因: 泛素融 合蛋白基因(GenBank 登录号为AF297036) 和核糖体蛋白L30 基因(GenBank 登录号是AF297033) 。前者cDNA 的开放阅读框为387 bp , 后者为348 bp 。前者编码128 个氨基酸残基组成的泛素融合蛋白前体; 后者编码115 个氨基酸残基组成的核糖体蛋白L30 前体。由cDNA 序列推导出的氨基酸序列分析表明, 泛素融合蛋白前体包 括N - 末端的泛素结构域(76 个氨基酸残基) 和C - 末端的核糖体蛋白L40 结构域(52 个氨基酸残基) 。该蛋 白为一高碱性蛋白, C 末端含有一个“锌指”模式结构。与16 个物种比较的结果表明, 眼镜王蛇与脊椎动物的 泛素融合蛋白氨基酸序列相似度较高, 具有高度的保守性。

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 对大银鱼和小齿日本银鱼的线粒体细胞色素b 和16S rRNA 基因片段进行了扩增和序列测定,分析比较了2 种 间的序列差异。大银鱼2 个个体间细胞色素b 基因序列无差异,小齿日本银鱼3 个个体的序列出现了2 种单倍型;大银鱼 同小齿日本银鱼细胞色素b 序列(单倍型SB21) 之间存在86 个碱基差异(差异率21 %) ,变异较大。大银鱼、小齿日本银鱼 的16S rRNA 基因片段种内个体间无序列差异,两种间存在21 个碱基的差异(差异率5 %) ,有1 个碱基的插入/ 缺失。由 此可见,2 种银鱼间线粒体细胞色素b 基因的进化速率较快,约为16S rRNA 基因片段的4 倍。根据细胞色素b 序列数据, 推算出2 种银鱼大概在中新世晚期发生分化。

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双尾虫是否单系,以及双尾虫与其他六足动物系统关系是多年来动物分类学家争议的一个关键问题。测定了双尾虫的两大类群:康 类和铗 类,以及原尾虫、跳虫和蝗虫等核糖体RNA基因18SrDNA全序列和28SrDNA部分序列(D3-D5区),并选用甲壳动物卤虫为外群,采用最大筒约(MP)法构建分子系统树。结果表明:(i)18SrDNA和28SrDNA数据整合分析含有较强的系统发育信息,支持双尾虫单系性观点;(ii)双尾虫与原尾虫在系统中构成姊姝群,且支持率很高。

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Phylogenetic relationships among representative species of the family Rhacophoridae were investigated based on 2904 bp of sequences from both mitochondrial (12S rRNA, 16S rRNA, the complete t-RNA for valine), and nuclear (tyrosinase, rhodopsin) genes. Max

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The monophyly of Diplura and its phylogenetic relationship with other hexapods are important for understanding the phylogeny of Hexapoda. The complete 18SrRNA gene and partial 28SrRNA gene (D3-D5 region) from 2 dipluran species (Campodeidae and Japygidae), 2 proturan species, 3 collembolan species, and 1 locust species were sequenced. Combining related sequences in GenBank, phylogenetic trees of Hexapoda were constructed by MP method using a crustacean Artemia salina as an outgroup. The results indicated that: (i) the integrated data of 18SrDNA and 28SrDNA could provide better phylogenetic information, which well supported the monophyly of Diplura; (ii) Diplura had a close phylogenetic relationship to Protura with high bootstrap support.

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A 3. 6 ns molecular dynamics simulation was carried out on the complex system of tobramycin and 16S rRNA in order to understand the speciality recognition mechanism between tobramycin and 16S rRNA at the molecular level. The results demonstrate that two l

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Understanding the dynamics of eukaryotic transcriptome is essential for studying the complexity of transcriptional regulation and its impact on phenotype. However, comprehensive studies of transcriptomes at single base resolution are rare, even for modern organisms, and lacking for rice. Here, we present the first transcriptome atlas for eight organs of cultivated rice. Using high-throughput paired-end RNA-seq, we unambiguously detected transcripts expressing at an extremely low level, as well as a substantial number of novel transcripts, exons, and untranslated regions. An analysis of alternative splicing in the rice transcriptome revealed that alternative cis-splicing occurred in similar to 33% of all rice genes. This is far more than previously reported. In addition, we also identified 234 putative chimeric transcripts that seem to be produced by trans-splicing, indicating that transcript fusion events are more common than expected. In-depth analysis revealed a multitude of fusion transcripts that might be by-products of alternative splicing. Validation and chimeric transcript structural analysis provided evidence that some of these transcripts are likely to be functional in the cell. Taken together, our data provide extensive evidence that transcriptional regulation in rice is vastly more complex than previously believed.

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RNAi(RNA interference)为研究未知功能基因提供了新的反向遗传学手段;并能应用于人类的基因治疗。文中就RNAi的研究进展、作用机制及其应用进行了评述,并与基因敲除及反义RNA抑制进行了比较。