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101.
Splenic vasculitis,thrombosis, and infarction in a febrile dog infected with Bartonella henselae
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102.
Cortical constriction during abscission involves helices of ESCRT-III-dependent filaments 总被引:1,自引:0,他引:1
Guizetti J Schermelleh L Mäntler J Maar S Poser I Leonhardt H Müller-Reichert T Gerlich DW 《Science (New York, N.Y.)》2011,331(6024):1616-1620
After partitioning of cytoplasmic contents by cleavage furrow ingression, animal cells remain connected by an intercellular bridge, which subsequently splits by abscission. Here, we examined intermediate stages of abscission in human cells by using live imaging, three-dimensional structured illumination microscopy, and electron tomography. We identified helices of 17-nanometer-diameter filaments, which narrowed the cortex of the intercellular bridge to a single stalk. The endosomal sorting complex required for transport (ESCRT)-III co-localized with constriction zones and was required for assembly of 17-nanometer-diameter filaments. Simultaneous spastin-mediated removal of underlying microtubules enabled full constriction at the abscission site. The identification of contractile filament helices at the intercellular bridge has broad implications for the understanding of cell division and of ESCRT-III-mediated fission of large membrane structures. 相似文献
103.
Tang L Shah S Chung L Carney J Katz L Khosla C Julien B 《Science (New York, N.Y.)》2000,287(5453):640-642
The polyketide epothilone is a potential anticancer agent that stabilizes microtubules in a similar manner to Taxol. The gene cluster responsible for epothilone biosynthesis in the myxobacterium Sorangium cellulosum was cloned and completely sequenced. It encodes six multifunctional proteins composed of a loading module, one nonribosomal peptide synthetase module, eight polyketide synthase modules, and a P450 epoxidase that converts desoxyepothilone into epothilone. Concomitant expression of these genes in the actinomycete Streptomyces coelicolor produced epothilones A and B. Streptomyces coelicolor is more amenable to strain improvement and grows about 10-fold as rapidly as the natural producer, so this heterologous expression system portends a plentiful supply of this important agent. 相似文献
104.
Pejchal R Doores KJ Walker LM Khayat R Huang PS Wang SK Stanfield RL Julien JP Ramos A Crispin M Depetris R Katpally U Marozsan A Cupo A Maloveste S Liu Y McBride R Ito Y Sanders RW Ogohara C Paulson JC Feizi T Scanlan CN Wong CH Moore JP Olson WC Ward AB Poignard P Schief WR Burton DR Wilson IA 《Science (New York, N.Y.)》2011,334(6059):1097-1103
The HIV envelope (Env) protein gp120 is protected from antibody recognition by a dense glycan shield. However, several of the recently identified PGT broadly neutralizing antibodies appear to interact directly with the HIV glycan coat. Crystal structures of antigen-binding fragments (Fabs) PGT 127 and 128 with Man(9) at 1.65 and 1.29 angstrom resolution, respectively, and glycan binding data delineate a specific high mannose-binding site. Fab PGT 128 complexed with a fully glycosylated gp120 outer domain at 3.25 angstroms reveals that the antibody penetrates the glycan shield and recognizes two conserved glycans as well as a short β-strand segment of the gp120 V3 loop, accounting for its high binding affinity and broad specificity. Furthermore, our data suggest that the high neutralization potency of PGT 127 and 128 immunoglobulin Gs may be mediated by cross-linking Env trimers on the viral surface. 相似文献
105.
106.
湖南烟溪病圃稻瘟病菌的有性态及微卫星标记的遗传多样性分析 总被引:7,自引:0,他引:7
用2对稻瘟病菌的两性能育菌株(交配型1.1和交配型1.2)测定了来自湖南烟溪病圃上的4年124个稻瘟病菌株的交配型,用微卫星分子标记分析其中105个菌株的遗传多样性及其亲缘关系。 124个菌株中, 28个为交配型1.1, 39个为交配型1.2, 57个不育, 分别占供试菌株的22.58%、31.45%和45.97%;在0.67相似性的基础上,7对微卫星引物扩增出的标记可将105个菌株区分为6个系谱群。 相似文献
107.
Tendro Radanielina Alain Ramanantsoanirina Louis-Marie Raboin Julien Frouin Xavier Perrier Philippe Brabant Nourollah Ahmadi 《Genetic Resources and Crop Evolution》2013,60(1):311-323
In situ conservation of crop genetic resources is widely recommended but, as yet, no methods have been developed to rank the genetic entities to preserve and the social organisations to involve. The highlands of Madagascar have been identified as a key site for rice, Oryza sativa, genetic diversity. To define conservation strategies, we performed multidisciplinary analysis of rice genetic diversity and factors shaping its distribution in the target region. Along with the indica and japonica rice subspecies of O. sativa, we confirmed the presence of an atypical rice group with a preferential habitat of 1,250–1,750 m. Spatial distribution of genetic diversity was uneven. The most determining factor of this unevenness was the altitude authorising or not the presence of different rice cropping systems and the associated types of varieties. Village and individual farmer’s wealth also had a determining role on the amount of rice diversity they hosted. While molecular variance between villages in a given interval of altitude represented 16 % of the total variance, within-village variance represented more than 75 % of the total, and within-farm variance 70 % of within-village variance. This hierarchical distribution of molecular variance suggests that a small number of samples per scale (altitude interval, village and farm) could allow to capture most of the genetic diversity observed. However, within-variety diversity was also important making ex situ conservation strategies impractical and costly. Implications of the within-variety diversity are discussed in terms of adaptive advantages, evolutionary processes, and need for in situ conservation. 相似文献
108.
Ghislaine Le Gall-Reculé Antonio Lavazza Stéphane Marchandeau Stéphane Bertagnoli Fran?oise Zwingelstein Patrizia Cavadini Nicola Martinelli Guerino Lombardi Jean-Luc Guérin Evelyne Lemaitre Anouk Decors Samuel Boucher Bernadette Le Normand Lorenzo Capucci 《Veterinary research》2013,44(1):81
Since summer 2010, numerous cases of Rabbit Haemorrhagic Disease (RHD) have been reported in north-western France both in rabbitries, affecting RHD-vaccinated rabbits, and in wild populations. We demonstrate that the aetiological agent was a lagovirus phylogenetically distinct from other lagoviruses and which presents a unique antigenic profile. Experimental results show that the disease differs from RHD in terms of disease duration, mortality rates, higher occurrence of subacute/chronic forms and that partial cross-protection occurs between RHDV and the new RHDV variant, designated RHDV2. These data support the hypothesis that RHDV2 is a new member of the Lagovirus genus. A molecular epidemiology study detected RHDV2 in France a few months before the first recorded cases and revealed that one year after its discovery it had spread throughout the country and had almost replaced RHDV strains. RHDV2 was detected in continental Italy in June 2011, then four months later in Sardinia. 相似文献
109.
110.
Claire Billy François Birgand Patrick Ansart Julien Peschard Mathieu Sebilo Julien Tournebize 《Landscape Ecology》2013,28(4):665-684
Land managers need to clearly identify the main natural factors controlling nitrate attenuation from upstream to downstream in agricultural watersheds. All interfaces between surface waters and groundwaters such as riparian zones could be identified as retention zones in the watershed. However, in highly human-influenced agricultural landscapes, retention zones could be shortcut, abandoned and sometimes erased. Starting from this situation, this paper aims to underline the role of hydrological and biogeochemical retention processes in the determination of nitrate concentration in an artificially drained agricultural watershed. The Orgeval watershed (East part of Paris, France, belonging to a long-term environmental observatory network) is 80 % covered by drained agricultural plots, 17 % forest and 3 % urban areas and roads, covering a surface area of 104 km2. The watershed is split into several nested sub-basins from 1 to 100 km2. Two levels of monitoring were carried out in the 2007–2008 hydrological year: long-term at six monitoring stations (measuring nitrate concentration and discharge) and 20 points throughout the watershed (measuring discharge, chloride, nitrate, sulphate, calcium concentration and nitrogen isotopic composition) for three different dates (10/18/2007, 01/23/2008, 04/10/2008). Artificial drainage generates modified water transfer and thus nitrate transformation processes during the wet drainage season in winter. Dilution processes provided by forested areas seem to be one of the main factor determining global water quality. A threshold of 34 % forested cover maintains the nitrate concentration below the drinking-water limit (11.3 mgN L?1). Nevertheless, statistical analysis, isotopic measurements and the analysis of the nitrate versus chloride ratio showed that retention processes also influence water quality during the dry season. 相似文献