Photodynamic inactivation of infectious nucleic acid

Tobacco mosaic virus-infectious nucleic acid causes a color shift when combined with acridine orange, methylene blue, and safranine. A high concentration of acridine orange inactivates infectious nucleic acid even in darkness, while a mixture of nucleic acid with a low concentration of the dye must be exposed to visible light prior to inoculation for inactivation to occur.     

Adaptive recognition by nucleic acid aptamers

Nucleic acid molecules play crucial roles in diverse biological processes including the storage, transport, processing, and expression of the genetic information. Nucleic acid aptamers are selected in vitro from libraries containing random sequences of up to a few hundred nucleotides. Selection is based on the ability to bind ligand molecules with high affinity and specificity. Three-dimensional structures have been determined at high resolution for a number of aptamers in complex with their cognate ligands. Structures of aptamer complexes reveal the key molecular interactions conferring specificity to the aptamer-ligand association, including the precise stacking of flat moieties, specific hydrogen bonding, and molecular shape complementarity. These basic principles of discriminatory molecular interactions in aptamer complexes parallel recognition events central to many cellular processes involving nucleic acids.     

核酸疫苗全球专利简析

为分析核酸疫苗相关专利申请分布和保护状况,促进我国核酸疫苗的研究开发,强化核酸疫苗知识产权保护和运用,本研究基于专利数据库收录的核酸疫苗相关专利的公开信息,在Incopat数据库中通过关键词和IPC分类号检索,分析其专利申请趋势、地域分布和技术领域分布,并重点分析BioNTech和Inovio两家重点公司的核酸疫苗专利布局情况。结果表明,共获得相关专利申请12 746项,核酸疫苗专利申请量维持在较高水平,技术产出国和目标市场国主要包括美国、中国和其他欧美发达国家,主要申请机构多为欧美国家研发机构,BioNTech和Inovio等重点研发机构的专利布局呈现多层次、长周期、广地域等特点。本研究为我国疫苗研发企业提供了适配新专利法、强化布局和灵活运营等方面的知识产权策略,希望为我国核酸疫苗技术的发展提供参考。     

Origin of life. A simpler nucleic acid

What was the genetic material of the earliest life forms on Earth if it was not RNA? As Orgel explains in his Perspective, the answer may be simpler nucleic acid polymers perhaps like the RNA analogs called (L)-a-threofuranosyl oligonucleotides or TNAs (Sch?ning et al.). These molecules have threose rather than ribose in their sugar-phosphate backbones and yet retain many of the properties of RNA including the ability to pair up in double helices.     

Potential metal-binding domains in nucleic acid binding proteins

A systematic search for sequences that potentially could form metal-binding domains in proteins has been performed. Five classes of proteins involved in nucleic acid binding or gene regulation were found to contain such sequences. These observations suggest numerous experiments aimed at determining whether metal-binding domains are present in these proteins and, if present, what roles such domains play in the processes of nucleic acid binding and gene regulation.     

核酸疫苗研究新进展

核酸疫苗是90年代初从基因治疗研究领域发展起来的一种全新疫苗,又称为DNA疫苗或基因疫苗,它是把编码免疫原或与免疫原相关的外源基因克隆到真核质粒表达载体上,然后将重组的质粒DNA直接注射到动物体内,使外源基因在动物体内表达,产生的抗原激活机体的免疫系统,引发免疫反应,从而达到预防和治疗疾病的目的.与传统的灭活或弱毒疫苗、亚单位疫苗相比,核酸疫苗以具有高效性、安全性和制备简单、易于贮存运输等优点,而受到全世界的普遍关注,具有广阔的发展前景.     

邻羟基苯甲酸胁迫对不同杉木无性系叶片核酸和蛋白质合成的影响

以对邻羟基苯甲酸胁迫具有不同抗性2个杉木无性系(即忍耐型和敏感型)为对象,分析胁迫对叶片遗传物质合成的影响.结果表明:邻羟基苯甲酸胁迫对忍耐型的DNA合成多表现为抑制效应,RNA合成多表现为促进效应.而对敏感型的DNA合成多表现为促进效应,RNA合成表现为抑制效应;在胁迫初期时各胁迫浓度对敏感型的蛋白质含量的促进效应大于忍耐型,但在胁迫中后期,而对敏感型的促进效应呈下降趋势,而对忍耐型的促进效应随胁迫浓度加大而不断增大,蛋白质合成能力不断提高.表明不同抗性杉木无性系基因表达调控模式存在较大差别,随着胁迫强度增大,忍耐型RNA和蛋白质的合成量增加,使更多的蛋白质参与了对此种胁迫的响应,而使其有更好的抗逆性.     

应用逆转录套式PCR检测禽流感病毒核酸研究

选择禽流感病毒NP基因 ,设计并合成一对外引物和一对内引物 ,建立并优化了检测禽流感病毒核酸的逆转录套式PCR法 ,通过实验室检测结果证明 ,该方法具有高度的特异性和敏感性 ,能够用于检测所有的禽流感病毒核酸 ,最低能检测出 0 2pg的AIVRNA ;临床应用结果表明 ,该方法能够应用于规模化鸡场进行禽流感病毒检测 ,淘汰带毒或隐性感染鸡群     

磁性微粒在核酸研究中的应用

磁性微粒作为固相载体应用于生物分子的合成、分离和检测,是一种非常有效、快速和方便的方法。在挪威、英、美、德等国已实现了商业化并得到了广泛的应用,而我国目前还处于研究阶段。对磁性微粒在mRNA的分离与纯化、DNA的分离与纯化以及核酸的杂交、扩增、检测等核酸研究领域中的应用进行了较为全面的综述。     

植物核酸营养素在葡萄生产中的应用

以8年生葡萄品种为试材,采用叶面喷施方法,研究了植物核酸营养素对葡萄生育的影响。结果表明,植物核酸营养素时葡萄黄叶转绿,叶片增厚、枝条成熟和提高果实品质等方面效果明显;平均单粒重比时照增加18．1％,可溶性固性物含量平均提高2．0％．每667m2产值平均提高24．5％;投入产出比为1：19。     

口蹄疫核酸疫苗的研究进展

核酸疫苗不仅引起体液免疫反应,而且诱导较高水平的细胞免疫应答,尤其是细胞毒T淋巴细胞(CTL)反应,被认为在抗病毒、胞内菌、寄生虫等病原体感染中具有更大的优势。随着对核酸疫苗研究的深入,越来越多的科研人员将其运用到口蹄疫防治研究中,并获得了一定的成效。     

核酸免疫制备豇豆胰蛋白酶抑制剂抗体的制备及初步应用

通过构建pcDNA3．1-CpTI真核表达载体，肌肉注射免疫Balb／c纯系小鼠，获得特异性的核酸免疫CpTI抗体，其效价达1：800，所获抗体可与纯化的CpTI蛋白发生特异性反应，检测OD406值和包被蛋白量相关系数为0．9961；间接法测定转cpti基因水稻结果表明，核酸免疫制备的抗体能与转基因水CpTI蛋白产生特异性反应，可用于转基因水稻cpti基因表达的定性测定。     

Self-assembled water-soluble nucleic acid probe tiles for label-free RNA hybridization assays

The DNA origami method, in which long, single-stranded DNA segments are folded into shapes by short staple segments, was used to create nucleic acid probe tiles that are molecular analogs of macroscopic DNA chips. One hundred trillion probe tiles were fabricated in one step and bear pairs of 20-nucleotide-long single-stranded DNA segments that act as probe sequences. These tiles can hybridize to their targets in solution and, after adsorption onto mica surfaces, can be examined by atomic force microscopy in order to quantify binding events, because the probe segments greatly increase in stiffness upon hybridization. The nucleic acid probe tiles have been used to study position-dependent hybridization on the nanoscale and have also been used for label-free detection of RNA.     

The obesity-associated FTO gene encodes a 2-oxoglutarate-dependent nucleic acid demethylase

Variants in the FTO (fat mass and obesity associated) gene are associated with increased body mass index in humans. Here, we show by bioinformatics analysis that FTO shares sequence motifs with Fe(II)- and 2-oxoglutarate-dependent oxygenases. We find that recombinant murine Fto catalyzes the Fe(II)- and 2OG-dependent demethylation of 3-methylthymine in single-stranded DNA, with concomitant production of succinate, formaldehyde, and carbon dioxide. Consistent with a potential role in nucleic acid demethylation, Fto localizes to the nucleus in transfected cells. Studies of wild-type mice indicate that Fto messenger RNA (mRNA) is most abundant in the brain, particularly in hypothalamic nuclei governing energy balance, and that Fto mRNA levels in the arcuate nucleus are regulated by feeding and fasting. Studies can now be directed toward determining the physiologically relevant FTO substrate and how nucleic acid methylation status is linked to increased fat mass.