Molecular characterisation and inductive expression of a fish protein arginine methyltransferase 1 gene in response to virus infection

Protein arginine methyltransferase 1 (PRMT1) is currently thought as an effector to regulate interferon (IFN) signalling. Here Paralichthys olivaceus PRMT1 (PoPRMT1) gene was identified as a vitally induced gene from UV-inactivated Scophthalmus maximus Rhabdovirus (SMRV)-infected flounder embryonic cells (FEC). PoPMRT1 encodes a 341-amino-acid protein that shares the conserved domains including post-I, motif I, II and III. Homology comparisons show that the putative PoPMRT1 protein is the closest to zebrafish PMRT1 and belongs to type I PRMT family (including PRMT1, PRMT2, PRMT3, PRMT4, PRMT6, PRMT8). Expression analyses revealed an extensive distribution of PoPMRT1 in all tested tissues of flounder. In vitro induction of PoPRMT1 was determined in UV-inactivated SMRV-infected FEC cells, and under the same conditions, flounder Mx wash also transcriptionally up-regulated, indicating that an IFN response might be triggered. Additionally, live SMRV infection of flounders induced an increased expression of PoPRMT1 mRNA and protein significantly in spleen, and to a lesser extent in head kidney and intestine. Immunofluorescence analysis revealed a major cyptoplasmic distribution of PoPRMT1 in normal FEC but an obvious increase occurred in nucleus in response to UV-inactivated SMRV. This is the first report on in vitro and in vivo expression of fish PRMT1 by virus infection, suggesting that PoPRMT1 might be implicated in flounder antiviral immune response. (c) 2006 Elsevier Ltd. All rights reserved.

The structural transition of DNA-Tris(1,10-phenanthroline) cobalt(III) complexes in ethanol-water solution

The interaction of DNA with Tris(1,10-phenanthroline) cobalt(III) was studied by means of atomic force microscopy. Changes in the morphologies of DNA complex in the presence of ethanol may well indicate the crucial role of electrostatic force in causing DNA condensation. With the increase of the concentration of ethanol, electrostatic interaction is enhanced corresponding to a lower dielectric constant. Counterions condense along the sugar phosphate backbone of DNA when e is lowered and the phosphate charge density can thus be neutralized to the level of DNA condensation. Electroanalytical measurement of DNA condensed with Co(phen)(3)(3+) in ethanol solution indicated that intercalating reaction remains existing. According to both the microscopic and spectroscopic results, it can be found that no secondary structure transition occurs upon DNA condensing. B-A conformation transition takes place at more than 60% ethanol solution.

Identification of a novel DNA methyltransferase 2 from the brine shrimp, Artemia franciscana

DNA methyltransferase 2 (Dnmt2) is a dual-specificity DNA methyltransferase, which contains a weak DNA methyltransferase and novel tRNA methyltransferase activity. However, its biological function is still enigmatic. To elucidate the expression profiles of Dnmt2 in Artemia franciscana, we isolated the gene encoding a Dnmt2 from A. franciscana and named it as AfDnmt2. The cDNA of AfDnmt2 contained a 1140-bp open reading frame that encoded a putative Dnmt2 protein of 379 amino acids exhibiting 32%similar to 39% identities with other known Dnmt2 homologs. This is the first report of a DNA methyltransferase gene in Crustacean. By using semi-quantitative RT-PCR, A)Dnmt2 was found to be expressed through all developmental stages and its expression increased during resumption of diapause cysts development. Southern blot analysis indicated the presence of multiple copies of AfDnmt2 genes in A. franciscana. (C) 2007 Published by Elsevier Inc.

A Simple, Universal Colorimetric Assay for Endonuclease/Methyltransferase Activity and Inhibition Based on an Enzyme-Responsive Nanoparticle System

An enzyme responsive nanoparticle system that uses a DNA-gold nanoparticle (AuNP) assembly as the substrate has been developed for the simple, sensitive, and universal monitoring of restriction endonucleases in real time. This new assay takes advantage of the palindromic recognition sequence of the restriction nucleases and the unique optical properties of AuNPs and is simpler than the procedure previously described by by Xu et al. (Angew. Chem. Int. Ed. Engl. 2007, 46, 3468-3470). Because it involves only one type of ssDNA modified AuNPs, this assay can be directed toward most of the endonucleases by simply changing the recognition sequence found within the linker DNA. In addition, the endonuclease activity could be quantitatively analyzed by the value of the reciprocal of hydrolysis half time (t(1/2)(-1). Furthermore, our new design could also be applied to the assay of methyltransferase activity since the methylation of DNA inhibits its cleavage by the corresponding restriction endonuclease, and thus, this new methodology can be easily adapted to high-throughput screening of methyltransferase inhibitors.

云南4个少数民族的随机扩增多态DNA分析

1990年,Williams和Welsh领导的2个小组几乎同时独立地发展起来一项新技术,即随机扩增多态DNA(Random amplified polymorphic DNA,RAPD).该技术通过PCR进行DNA扩增,所用引物是G+C含量为50%—70%的单个随机短引物,这些引物在一定的退火条件下能与基因组DNA中的互补顺序配对,启动DNA的合成.RAPD具有以下特点:(1)无需预先知道受试有机体基因组DNA的序列,因而能应用于所用的生物体;(2)绝大多数

鹿鞭的微量DNA提取及序列鉴定

采用微量DNA提取技术,从梅花鹿血、毛、鹿鞭、鹿茸、牛鞭、驴鞭中提取DNA,以线粒体DNA细胞色素b通用引物L14841和H15149扩增约307bpDNA片段, 扩增产物纯化后采用双脱氧链终止法测定其序列。结果证明:梅花鹿毛、血和鹿鞭的DNA序列完全一致; 而所谓的“鹿茸”则与其有较大的差异。用所测序列以简约法PAUP3.1.1 程序构建的分子系统树与传统分类系统相吻合。

银姻自然群体线粒体DNA的遗传分化

运用21种限制性内切酶对银细自然群体进行了mtDNA的限制性片断长度多态性 (RFLP)分析。发现银姻自然群体存在丰富的mtDNA多态性，从4个群体39个个体中，共检测 到12种单倍型，对这一现象的成因进行了探讨。依据单倍型和群体的系统发育关系，结合地 理分布的资料，对其现今分布区相互间的历史联系及其对银姻起源和分化的影响进行了分析。

云南保山猪线粒体DNA D loop区序列初步分析

为了解云南保山猪(Baoshan pig)的遗传多样性及其遗传背景，我们测定了19个个体线粒体DNA Dloop高变区1 1 5 363 - 1 5 801片段序列438帅。检测到1。种单倍型，包括8个多态位点，其中5次T/ C转换、1次G/ A转换、1次G/ C颠换和1次A/ T颠换，其A.T.GX碱基的平均含量分别为35.4%.26.9%.13.2%和24.5 %,A+ T含量(62 .3)明显高于G+ C含量(37 .7 %)。对于保山猪的保种及其持续利用有着重要的理论指导意义。

贵州汉族、苗族、布依族和水族人群线粒体DNA多态性研究

用16种限制性内切酶对150个样本进行了mtDNA的限制性片段长度多态性(RFLP)分析。共检测到31种限制性格局, 其中Hae Ⅱ-13型、EcoRV-3型和PstⅠ-型3种限制性格局 为新报道。综合这些限制性格局, 共得出28种mtDNA类型。运用UPG法和简约法分析了各mtDNA类型之间、各人群之间的聚类关系。结果表明: 水族人群的mtDNA变异度较大; 汉族和苗族的亲缘关系最近, 布依族和水族有着较远的亲缘关系。图4表4参28

HIV-1感染对T和B细胞核内UNG2 mRNA表达的影响

目的:探讨HIV-1感染是否影响细胞中UNG2的表达.方法:采用四步法SYBR green Ⅰ实时定量RT-PCR,对HIV-1感染者的T和B淋巴细胞,以及HIV-1感染的C8166细胞核内UNG2 mRNA的表达进行测定.结果:UNG2 mRNA的表达在HIV-1感染者的T细胞和HIV-1感染的C8166细胞中被明显上调,分别是对照的8.76倍和8.14倍,而在HIV-1感染者的B细胞中却没有被上调.结论:HIV-1感染导致的UNG2表达上调,可能通过减少TCR的多样性削弱Th的功能,另一方面可能有利于病毒对UNG2的包装.

两个家系猪的DNA指纹图谱遗传分析

用人源小卫星探针33.6和33.15获得了两个家系猪的DNA指纹图谱。通过对F1和F2代家系分析,证实DNA指纹图带以孟德尔方式遗传。在家系2(探针33.6)的1个后代中发现了一条新突变带。文中还对这两个探针检测到的位点数进行了估测。

转基因鱼试验湖浮游生物群落DNA指纹与理化因子的关系

对转基因鱼试验湖7个采样点的浮游生物群落进行了PCR-DGGE指纹分析,并进而探讨了DNA指纹与理化因子的关系。结果表明:(1)PCR-DGGE指纹图谱中共含104谱带,其中原核谱带58条,真核谱带46条,其多态性位点分别为87.9%和82.6%。(2)各站点的理化因子中,Ⅰ站的TP含量最高(0.10mg/L),TN含量在Ⅲ站最高(0.34mg/L),且各站点波动较大,Ⅴ站的透明度最低(63.00cm);NO3-N、NH4-N、pH、DO、COD及电导率在各站点变化不大。基于原核生物图谱的相似性聚类分析表