Total chemical synthesis,assembly of human torque teno virus genome

Torque teno virus(TTV)is a nonenveloped virus containing a single-stranded,circular DNA genome of approximately 3.8kb.We completely synthesized the 3808 nucleotides of the TTV(SANBAN isolate)genome,which contains a hairpin structure and a GC-rich region.More than 100 overlapping oligonucleotides were chemically synthesized and assembled by polymerise chain assembly reaction(PCA),and the synthesis was completed with splicing by overlap extension(SOEing).This study establishes the methodological basis of the chemical synthesis of a viral genome for use as a live attenuated vaccine or gene therapy vector.     

From Virus Research to Molecular Biology: Tobacco Mosaic Virus in Germany, 1936-1956

In 1937, a group of researchers in Nazi Germany began investigating tobacco mosaic virus (TMV) with the hope of using the virus as a model system for understanding gene behavior in higher organisms. They soon developed a creative and interdisciplinary work style and were able to continue their research in the postwar era, when they made significant contributions to the history of molecular biology. This group is significant for two major reasons. First, it provides an example of how researchers were able to produce excellent scientific research in the midst of dictatorship and war.Coupled with the group's ongoing success in postwar Germany, the German TMV investigators provide a dramatic example of how scientific communities deal with adversity as well as rapid political and social change. Second, since the researchers focused heavily (though no exclusively) on TMV, their story allows us to analyze how an experimental system other than phage contributed to the emergence of molecular biology.     

Nucleoli and Stress Granules: Connecting Distant Relatives

Nucleoli and cytoplasmic stress granules (SGs) are subcellular compartments that modulate the response to endogenous and environmental signals to control cell survival. In our opinion, nucleoli and SGs are functionally linked; they are distant relatives that combine forces when cellular homeostasis is threatened. Several lines of evidence support this idea; nucleoli and SGs share molecular building blocks, are regulated by common signaling pathways and communicate when vital cellular functions become compromised. Together, nucleoli and SGs orchestrate physiological responses that are directly relevant to stress and human health. As both compartments have established roles in neurodegenerative diseases, cancer and virus infections, we propose that these conditions will benefit from therapeutic interventions that target simultaneously nucleoli and SGs.      

马传染性贫血病毒基因非编码区LTR嵌合克隆的构建

在已有全长感染性克隆pLGFD3-8和pD70344的基础上,根据马传贫弱毒疫苗致弱过程中不同代次毒株LTR序列的分析,在LTR U3区选取特定的酶切位点对EIAV非编码区LTR基因进行了部分替换.将替换的全基因克隆转染驴胎皮肤细胞(FDD)并以驴白细胞(DL)传代,用逆转录酶活性检测、RT-PCR方法及Real-time RT-PCR验证其感染性.结果发现,其衍生病毒感染上述两种细胞均出现明显的细胞病变;细胞培养上清可检测到RT酶活性和RT-PCR阳性.电镜下可见大量典型的EIAV颗粒.pLGFD9-12嵌合克隆衍生病毒与其父本克隆衍生病毒pLGFD3-8具有相似的复制水平,pLGFD9-12嵌合克隆衍生病毒在DL细胞上复制水平略高于FDD细胞.此结果为进一步深入研究LTR对马传染性贫血病毒复制水平和毒力的影响奠定了基础.     

Effects of aphidicolin on retrovirus DNA synthesis in vivo

Renaturation of $\text{Aequorea}$ green-fluorescent protein (A-GFP) was achieved for the first time following denaturation in guanidine-HCl or acid. Denaturation was accompanied by the concerted loss of visible fluorescence, alteration of absorption characteristics, and large negative deflection of CD signal in the far UV. Dialysis of a guanidine-denatured sample at pH 8 resulted in 64% renaturation (return to native absorption) and neutralization of an acid-denatured sample restored 90% of the native absorption. Renatured GFP is highly fluorescent and indistinguishable from native GFP with respect to the shape of excitation and emission spectra. Both native and denatured proteins exhibit resistance to trypsin hydrolysis and have identically broad pH and heat stability profiles, all of which suggest full renaturation.     

EB病毒潜伏膜蛋白-1介导的信号传导

EB病毒编码LMP-1介导的信号传导途径已引起人们广泛的注意.它涉及TRAF/TRADD途径,AP-1途径,JAK/STAT及其他途径.就此作一综述,有助于人们认识LMP-1的致瘤效应.     

Bioinformatic analysis of BBTV satellite DNA in Hainan

Banana bunchy top virus (BBTV),family Nanaviridae,genus Babuvirus,is a single stranded DNA virus (ssDNA) that causes banana bunchy top disease (BBTD) in banana plants.It is the most common and most destructive of all viruses in these plants and is widespread throughout the Asia-Pacific region.In this study we isolated,cloned and sequenced a BBTV sample from Hainan Island,China.The results from sequencing and bioinformatics analysis indicate this isolate represents a satellite DNA component with 12 DNA sequences motifs.We also predicted the physical and chemical properties,structure,signal peptide,phosphorylation,secondary structure,tertiary structure and functional domains of its encoding protein,and compare them with the corresponding quantities in the replication initiation protein of BBTV DNA1.     

烟粉虱携带番茄黄化曲叶病毒检测及其传入山东省的考证

【背景】番茄黄化曲叶病毒（TYLCV）是由媒介昆虫烟粉虱传播的一种双生病毒,对蔬菜及烟草等经济作物造成严重危害。前人资料表明,该病毒于2006年传人我国南方地区,2007年传人山东省,2008年后在山东各地逐渐蔓延扩散。【方法】为了考证TYLcV传人山东省的时间,本研究利用mtCOI基因对于2005和2006年7—8月份在山东省不同地区作物上共采集的15份烟粉虱样品进行了生物型鉴定,并进一步检测了烟粉虱携带TYLCV情况,同时对PCR扩增产物进行了测序分析。【结果】2005年的4份样品烟粉虱生物型均为B型,均不携带TYLCV。2006年的11份烟粉虱样品为B型与Q型混合样品,其中,2份烟粉虱样品检测到TYLCV,进一步证实该病毒为TYLCV。【结论与意义】本研究首次证实了TYLCV早在2006年就已经传入山东省。研究结果不仅对于防控该病毒具有重要指导意义,而且对于其入侵生物学研究也具有重要参考价值。     

CD63在戊型肝炎病毒感染中的作用机制

本研究旨在寻找戊型肝炎病毒(hepatitis E virus,HEV)衣壳蛋白ORF2的相互作用蛋白,探讨其在HEV感染中的作用。采用酵母双杂交方法从人肝细胞文库中筛选与HEV ORF2相互作用的蛋白,结果显示CD63与HEV ORF2相互作用。Pull-down实验提示原核表达的ORF2与CD63结合较弱,而免疫共沉淀实验提示真核表达的ORF2能与CD63结合。流式细胞术检测结果显示,HEV易感细胞PLC/PRF/5细胞膜表面的CD63表达水平普遍低于HEV非易感细胞。过表达CD63抑制PLC/PRF/5细胞的HEV感染,而小干扰RNA(small interfering RNA,siRNA)干扰CD63表达则促进HEV感染。结果提示,CD63能与HEV ORF2相互作用,可能抑制HEV感染肝细胞。