APOBEC-mediated editing of viral RNA

Retroviral DNA can be subjected to cytosine-to-uracil editing through the action of members of the APOBEC family of cytidine deaminases. Here we demonstrate that APOBEC-mediated cytidine deamination of human immunodeficiency virus (HIV) virion RNA can also occur. We speculate that the natural substrates of the APOBEC enzymes may extend to RNA viruses that do not replicate through DNA intermediates. Thus, cytosine-to-uracil editing may contribute to the sequence diversification of many viruses.     

Central synaptic inputs to identified leech neurons determined by peripheral targets

Developing Retzius (Rz) neurons in different segments of the central nervous system of the medicinal leech have different peripheral targets: Rz cells in standard segments innervate the body wall, whereas Rz cells in the reproductive segments innervate reproductive tissue. Early removal of reproductive tissue primordia causes reproductive Rz cells to develop morphologically like their standard segmental homologs, suggesting that Rz cells depend on peripheral targets for signals that determine their central and peripheral morphology. Furthermore, after removal of reproductive tissue, reproductive Rz cells also receive synaptic inputs normally appropriate for standard Rz cells. These results suggest that the functional identity of these neurons is specified by the target they contact during embryogenesis.     

An RNA ligase essential for RNA editing and survival of the bloodstream form of Trypanosoma brucei

RNA editing in trypanosomes occurs by a series of enzymatic steps that are catalyzed by a macromolecular complex. The TbMP52 protein is shown to be a component of this complex, to have RNA ligase activity, and to be one of two adenylatable proteins in the complex. Regulated repression of TbMP52 blocks editing, which shows that it is a functional component of the editing complex. This repression is lethal in bloodforms of the parasite, indicating that editing is essential in the mammalian stage of the life cycle. The editing complex, which is present in all kinetoplastid parasites, may thus be a chemotherapeutic target.     

Sequencing of Culex quinquefasciatus establishes a platform for mosquito comparative genomics

Culex quinquefasciatus (the southern house mosquito) is an important mosquito vector of viruses such as West Nile virus and St. Louis encephalitis virus, as well as of nematodes that cause lymphatic filariasis. C. quinquefasciatus is one species within the Culex pipiens species complex and can be found throughout tropical and temperate climates of the world. The ability of C. quinquefasciatus to take blood meals from birds, livestock, and humans contributes to its ability to vector pathogens between species. Here, we describe the genomic sequence of C. quinquefasciatus: Its repertoire of 18,883 protein-coding genes is 22% larger than that of Aedes aegypti and 52% larger than that of Anopheles gambiae with multiple gene-family expansions, including olfactory and gustatory receptors, salivary gland genes, and genes associated with xenobiotic detoxification.     

Requirement of the RNA editing deaminase ADAR1 gene for embryonic erythropoiesis

The members of the ADAR (adenosine deaminase acting on RNA) gene family are involved in site-selective RNA editing that changes adenosine residues of target substrate RNAs to inosine. Analysis of staged chimeric mouse embryos with a high contribution from embryonic stem cells with a functional null allele for ADAR1 revealed a heterozygous embryonic-lethal phenotype. Most ADAR1+/- chimeric embryos died before embryonic day 14 with defects in the hematopoietic system. Our results suggest the importance of regulated levels of ADAR1 expression, which is critical for embryonic erythropoiesis in the liver.     

系统方法在数据表编辑加工中的应用

结合系统方法中的整体性、相关性、层次性、动态性、科学性等原则,提炼出数据表编辑加工的系统分析三步法,将数据表看成是一个由相互联系的若干要素(表序、表题、表身、表注等)组成的整体。首先审查系统整体结构是否合理,再逐项审查各要素的科学性和规范性,最后,统筹考虑表与正文、插图内容的相关性,进行一致性审查。     

OsPPR9 encodes a DYW-type PPR protein that affects editing efficiency of multiple RNA editing sites and is essential for chloroplast development

Photosynthesis occurs mainly in chloroplasts, whose development is regulated by proteins encoded by nuclear genes.Among them, pentapeptide repeat(PPR) proteins participate in organelle RNA editing. Although there are more than 450members of the PPR protein family in rice, only a few affect RNA editing in rice chloroplasts. Gene editing technology has created new rice germplasm and mutants, which could be used for rice breeding and gene function study. This study evaluated the functions of OsPPR9...     

Acidic components of green river shale identified by a gas chromatography-mass spectrometry-computer system

A system consisting of a gas chromatograph coupled to a mass spectrometer and computer has been used to characterize the extractable acidic components of Green River shale. This system accumulates mass spectra at every point of the gas chromatogram in a permanent form which permits one to observe mass spectra of minor as well as major constituents. One minor component, whose identification was confirmed by synthesis, was 6,10,14-trimethyl-pentadecanoic acid.     

Fine mapping of powdery mildew resistance gene PmTm4 in wheat using comparative genomics

Powdery mildew,caused by Blumeria graminis f.sp.tritici,is one of the most severe wheat diseases.Mining powdery mildew resistance genes in wheat cultivars and their appliance in breeding program is a promising way to control this disease.Genetic analysis revealed that a single dominant resistance gene named PmTm4 originated from Chinese wheat line Tangmai 4 confers resistance to prevailing isolates of B.graminis f.sp.tritici isolate E09.Detailed comparative genomics analyses helped to develop closely linked markers to PmTm4 and a fine genetic map was constructed using large F_2 population,in which PmTm4 was located into a 0.66-c M genetic interval.The orthologous subgenome region of PmTm4in Aegilops tauschii was identified,and two resistance gene analogs(RGA)were characterized from the corresponding sequence scaffolds of Ae.tauschii draft assembly.The closely linked markers and identified Ae.tauschii orthologs in the mapping interval provide an entry point for chromosome landing and map-based cloning of PmTm4.     

浅谈非线性编辑系统及RAID技术

介绍非线性编辑系统的特点，重点论述了RAID数据存储技术及不同RAID级别的技术原理。     

植物病原细菌Pseudomonas syringae pv. tomato DC3000致病基因比较基因组及原核表达分析

番茄细菌性叶斑病是由Pseudomonas syringae pv. tomato引起的一种世界范围内广泛发生的植物细菌性病害,其模式菌株DC3000已完成全基因组测序。试验通过比较基因组学方法将该模式菌株基因组中的致病基因与其他已完成全基因组测序的植物病原细菌的基因组序列进行比对,得到3个DC3000菌株特有的致病基因PSPTO_4707、PSPTO_4708、PSPTO_4711,并对PSPTO_4711基因进行原核表达和蛋白活力检测,发现其表达的活性蛋白对拟南芥具有很强的毒性。     

OsDXR interacts with OsMORF1 to regulate chloroplast development and the RNA editing of chloroplast genes in rice

Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors. In this study, we identified OsDXR, a gene encoding a reductoisomerase that positively regulates chlorophyll biosynthesis and chloroplast development in rice. OsDXR knock-out lines displayed the albino phenotype and could not complete the whole life cycle process. OsDXR was highly expressed in rice leaves, and subcellular localization indicated that OsDXR i...     

红麻线粒体基因NAD3和COB的RNA编辑与表达分析

以红麻细胞质线粒体近等基因系UG93A(不育系)、UG93B(保持系)及UG93A×福红992(恢复系)的F1代为材料,研究花药线粒体基因NAD3和COB的转录与表达。结果发现,在3种供试材料中,基因NAD3的CDS区在DNA水平和RNA编辑水平上均无差异;不育系与保持系的COB基因DNA编码序列无差异,但在RNA水平上发生了编辑,8个位点的编辑均发生于密码子的第一或第二位碱基,且导致氨基酸种类变化,主要为亲水性氨基酸转变为疏水性氨基酸;COB基因在UG93A中的RNA编辑频率低于UG93B;NAD3和COB基因在3种材料中的转录本大小基本相同,但在表达水平上表现为不育系显著低于保持系和F1代。由此推测NAD3和COB基因在红麻花药发育过程中有着重要的作用。     

细菌sRNA调控靶标的双质粒筛选系统构建

以pMycVec1/pMycVec2载体为基础,构建了筛选和鉴定细菌sRNA调控靶标的双质粒系统。对pMycVec2载体的多克隆位点进行改造,并加入强启动子rrnBp和有效转录终止子,获得可定向克隆和转录sRNA的质粒pMycVec2-D;对pMycVec1载体的多克隆位点进行改造,并加入弱启动子Pwk和有效转录终止子,获得了分别用报告基因lacZ和GFP来检测sRNA靶标序列翻译水平的质粒pMycVec1-lacZ和pMycVec1-GFP。最后,利用2对已知的sRNA与其调控靶标MicC/ompC mRNA和MicF/ompF mRNA,通过β-半乳糖苷酶活性和菌体荧光值检测,表明双质粒系统能有效检测sRNA与调控靶标的互作。