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51.
52.
Contribution of the β‐glucosidase BglC to the onset of the pathogenic lifestyle of Streptomyces scabies 下载免费PDF全文
53.
A stochastic model of oil-palm (Elaeis guineensis Jacq.) root system architecture and development has been developed. This model enabled us to create 3-D numerical models of complete root systems by simulation. The application of a postprocessor software, called RACINES, to these 3-D numerical models, provided an estimation of some parameters of plant root systems. The objective of this paper is to present oil-palm root characteristics as possible outputs of the application of this RACINES software. The outputs described in this article cover (i) spatial distribution of roots under plantation conditions, (ii) the estimation and distribution of total root biomass, per root type or per soil horizon and (iii) the location and quantification of absorbent surfaces. The computing techniques used were based on voxellization of space and creation of 3-D virtual sceneries exactly reproducing observed planting designs. By comparing the results of observations and simulations for spatial distribution (by trench wall density maps) and root biomasses (by real and virtual sampling) we were able to carry out additional numerical validations of the model. 相似文献
54.
Rotavirus Infection Reduces Sucrase-Isomaltase Expression in Human Intestinal Epithelial Cells by Perturbing Protein Targeting and Organization of Microvillar Cytoskeleton 总被引:10,自引:5,他引:5 下载免费PDF全文
Nathalie Jourdan Jean Philippe Brunet Catherine Sapin Anne Blais Jacqueline Cotte-Laffitte Franoise Forestier Anne-Marie Quero Germain Trugnan Alain L. Servin 《Journal of virology》1998,72(9):7228-7236
Rotavirus infection is the most common cause of severe infantile gastroenteritis worldwide. These viruses infect mature enterocytes of the small intestine and cause structural and functional damage, including a reduction in disaccharidase activity. It was previously hypothesized that reduced disaccharidase activity resulted from the destruction of rotavirus-infected enterocytes at the villus tips. However, this pathophysiological model cannot explain situations in which low disaccharidase activity is observed when rotavirus-infected intestine exhibits few, if any, histopathologic changes. In a previous study, we demonstrated that the simian rotavirus strain RRV replicated in and was released from human enterocyte-like Caco-2 cells without cell destruction (N. Jourdan, M. Maurice, D. Delautier, A. M. Quero, A. L. Servin, and G. Trugnan, J. Virol. 71:8268–8278, 1997). In the present study, to reinvestigate disaccharidase expression during rotavirus infection, we studied sucrase-isomaltase (SI) in RRV-infected Caco-2 cells. We showed that SI activity and apical expression were specifically and selectively decreased by RRV infection without apparent cell destruction. Using pulse-chase experiments and cell surface biotinylation, we demonstrated that RRV infection did not affect SI biosynthesis, maturation, or stability but induced the blockade of SI transport to the brush border. Using confocal laser scanning microscopy, we showed that RRV infection induces important alterations of the cytoskeleton that correlate with decreased SI apical surface expression. These results lead us to propose an alternate model to explain the pathophysiology associated with rotavirus infection. 相似文献
55.
Sequence and conformation of 5 S RNA from Chlorella cytoplasmic ribosomes: comparison with other 5 S RNA molecules 总被引:12,自引:0,他引:12
The sequence of Chlorella cytoplasmic 5 S RNA has been determined by fingerprinting techniques. Partial digests were fractionated by a two-dimensional acrylamide gel electrophoretic technique, which indicates whether specific fragments are paired in the molecule. In this way, the four main base-paired regions of the molecule were located. The sequence of Chlorella cytoplasmic 5 S RNA is related to, but different from, that of other eukaryotic 5 S RNAs: it shows approximately 60% homology with vertebrate 5 S RNA and 40% homology with yeast 5 S RNA. In some respects the conformation of the molecule in solution is quite different from that of other sequenced 5 S RNAs: in particular, the highly accessible region found around position 40 in all other 5 S RNAs (prokaryotic and eukaryotic) does not exist in this molecule. 相似文献
56.
Pradier Céline Hinsinger Philippe Laclau Jean-Paul Bouillet Jean-Pierre Guerrini Irae Amaral Gonçalves José Leonardo Moraes Asensio Verónica Abreu-Junior Cassio H. Jourdan Christophe 《Plant and Soil》2017,414(1-2):339-354
Plant and Soil - Comparing root functioning under contrasting rainfall regimes can help assessing the capacity of plant species to cope with more intense and frequent drought predicted under... 相似文献
57.
Exploring the relationship between tychoparthenogenesis and inbreeding depression in the Desert Locust,Schistocerca gregaria 下载免费PDF全文
Chelsea J. Little Marie‐Pierre Chapuis Laurence Blondin Elodie Chapuis Hélène Jourdan‐Pineau 《Ecology and evolution》2017,7(15):6003-6011
Tychoparthenogenesis, a form of asexual reproduction in which a small proportion of unfertilized eggs can hatch spontaneously, could be an intermediate evolutionary link in the transition from sexual to parthenogenetic reproduction. The lower fitness of tychoparthenogenetic offspring could be due to either developmental constraints or to inbreeding depression in more homozygous individuals. We tested the hypothesis that in populations where inbreeding depression has been purged, tychoparthenogenesis may be less costly. To assess this hypothesis, we compared the impact of inbreeding and parthenogenetic treatments on eight life‐history traits (five measuring inbreeding depression and three measuring inbreeding avoidance) in four laboratory populations of the desert locust, Schistocerca gregaria, with contrasted demographic histories. Overall, we found no clear relationship between the population history (illustrated by the levels of genetic diversity or inbreeding) and inbreeding depression, or between inbreeding depression and parthenogenetic capacity. First, there was a general lack of inbreeding depression in every population, except in two populations for two traits. This pattern could not be explained by the purging of inbreeding load in the studied populations. Second, we observed large differences between populations in their capacity to reproduce through tychoparthenogenesis. Only the oldest laboratory population successfully produced parthenogenetic offspring. However, the level of inbreeding depression did not explain the differences in parthenogenetic success between all studied populations. Differences in development constraints may arise driven by random and selective processes between populations. 相似文献
58.
Bartlett NW Walton RP Edwards MR Aniscenko J Caramori G Zhu J Glanville N Choy KJ Jourdan P Burnet J Tuthill TJ Pedrick MS Hurle MJ Plumpton C Sharp NA Bussell JN Swallow DM Schwarze J Guy B Almond JW Jeffery PK Lloyd CM Papi A Killington RA Rowlands DJ Blair ED Clarke NJ Johnston SL 《Nature medicine》2008,14(2):199-204
Rhinoviruses cause serious morbidity and mortality as the major etiological agents of asthma exacerbations and the common cold. A major obstacle to understanding disease pathogenesis and to the development of effective therapies has been the lack of a small-animal model for rhinovirus infection. Of the 100 known rhinovirus serotypes, 90% (the major group) use human intercellular adhesion molecule-1 (ICAM-1) as their cellular receptor and do not bind mouse ICAM-1; the remaining 10% (the minor group) use a member of the low-density lipoprotein receptor family and can bind the mouse counterpart. Here we describe three novel mouse models of rhinovirus infection: minor-group rhinovirus infection of BALB/c mice, major-group rhinovirus infection of transgenic BALB/c mice expressing a mouse-human ICAM-1 chimera and rhinovirus-induced exacerbation of allergic airway inflammation. These models have features similar to those observed in rhinovirus infection in humans, including augmentation of allergic airway inflammation, and will be useful in the development of future therapies for colds and asthma exacerbations. 相似文献
59.
SUMMARY: We present a Cytoscape plugin for the inference and visualization of networks from high-resolution mass spectrometry metabolomic data. The software also provides access to basic topological analysis. This open source, multi-platform software has been successfully used to interpret metabolomic experiments and will enable others using filtered, high mass accuracy mass spectrometric data sets to build and analyse networks. AVAILABILITY: http://compbio.dcs.gla.ac.uk/fabien/abinitio/abinitio.html 相似文献
60.
Simon Duval Anne-Lise Ducluzeau Wolfgang Nitschke Barbara Schoepp-Cothenet 《BMC evolutionary biology》2008,8(1):206