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201.
Gonzalez N Gévaudant F Hernould M Chevalier C Mouras A 《The Plant journal : for cell and molecular biology》2007,51(4):642-655
Tomato fruit size results from the combination of cell number and cell size which are respectively determined by cell division and cell expansion processes. As fruit growth is mainly sustained by cell expansion, the development of pericarp and locular tissues is characterized by the concomitant arrest of mitotic activity, inhibition of cyclin-dependent kinase (CDK) activity, and numerous rounds of endoreduplication inducing a spectacular increase in DNA ploidy and mean cell size. To decipher the molecular basis of the endoreduplication-associated cell growth in fruit, we investigated the putative involvement of the WEE1 kinase (Solly;WEE1). We here report a functional analysis of Solly;WEE1 in tomato. Impairing the expression of Solly;WEE1 in transgenic tomato plants resulted in a reduction of plant size and fruit size. In the most altered phenotypes, fruits displayed a reduced number of seeds without embryo development. The reduction of plant-, fruit- and seed size originated from a reduction in cell size which could be correlated with a decrease of the DNA ploidy levels. At the molecular level downregulating Solly;WEE1 in planta resulted in the increase of CDKA activity levels originating from a decrease of the amount of Y15-phosphorylated CDKA, thus indicating a release of the negative regulation on CDK activity exerted by WEE1. Our data indicated that Solly;WEE1 participates in the control of cell size and/or the onset of the endoreduplication process putatively driving cell expansion. 相似文献
202.
203.
204.
Sonia Montanari Xing-Hua Wang Gustavo Yannarelli Victor Dayan Thorsten Berger Larissa Zocche Eiji Kobayashi Sowmya Viswanathan Armand Keating 《Transgenic research》2014,23(5):779-793
The inbred rat is a suitable model for studying human disease and because of its larger size is more amenable to complex surgical manipulation than the mouse. While the rodent fulfills many of the criteria for transplantation research, an important requirement is the ability to mark and track donors cells and assess organ viability. However, tracking ability is limited by the availability of transgenic (Tg) rats that express suitable luminescent or fluorescent proteins. Red fluorescent protein cloned from Discosoma coral (DsRed) has several advantages over other fluorescent proteins, including in vivo detection in the whole animal and ex vivo visualization in organs as there is no interference with autofluorescence. We generated and characterized a novel inbred Tg Lewis rat strain expressing DsRed monomeric (DsRed mono) fluorescent protein under the control of a ubiquitously expressed ROSA26 promoter. DsRed mono Tg rats ubiquitously expressed the marker gene as detected by RT-PCR but the protein was expressed at varying levels in different organs. Conventional skin grafting experiments showed acceptance of DsRed monomeric Tg rat skin on wild-type rats for more than 30 days. Cardiac transplantation of DsRed monomeric Tg rat hearts into wild-type recipients further showed graft acceptance and long-term organ viability (>6 months). The DsRed monomeric Tg rat provides marked cells and/or organs that can be followed for long periods without immune rejection and therefore is a suitable model to investigate cell tracking and organ transplantation. 相似文献
205.
Michel Kayomo Kaswa Serge Bisuta Georges Kabuya Octavie Lunguya André Ndongosieme Jean Jacques Muyembe Armand Van Deun Marleen Boelaert 《PloS one》2014,9(4)
Multidrug Resistant Tuberculosis (MDR-TB) is a serious threat which jeopardizes the worldwide efforts to control TB. The Democratic Republic of Congo (DRC) is one of 27 countries with a high burden of MDR-TB. Data on the magnitude, trends, and the distribution of MDR-TB in DRC are scanty. Kinshasa, the capital city of DRC which accounts for 20% of all TB cases nationwide, is notifying more than 80% of all MDR suspects. We report here a cluster of MDR-TB cases that was investigated in the Mosango health district, in the Bandundu south Province, DRC in 2008. Phenotypic Drug Sensitivity Testing and DNA sequencing were performed on 18 sputum specimens collected from 4 MDR-TB suspects and 5 household contacts. Sequencing data confirmed that the 4 suspects were indeed Rifampicin resistant cases. Sequencing of the rpoB gene showed that 3 cases (patients A, B and D) had a single mutation encoding a substitution to 526Tyr, 531Trp and 526Leu respectively. Patient C had a double mutation encoding a change to 531Leu and 633Leu. Two of the investigated cases died within 4 months of a second-line treatment course. Results highlight the need to enhance adequate laboratory services within the country for both clinical as well as surveillance purposes. 相似文献
206.
Mona Rahmati Marie Petitbarat Sylvie Dubanchet Armand Bensussan Gerard Chaouat Nathalie Ledee 《PloS one》2014,9(10)
Introduction
Recombinant human Granulocyte-Colony Stimulating Factor (rhG-CSF) supplementation seems to be a promising innovative therapy in reproductive medicine, used in case of recurrent miscarriage, embryo implantation failure or thin endometrium, although its mechanisms of action remain unknown. Our aim was to identify possible endometrial pathways influenced by rhG-CSF.Materials and Methods
Hypothetical molecular interactions regulated by G-CSF were designed through a previous large scale endometrial microarray study. The variation of endometrial expression of selected target genes was confirmed in control and infertile patients. G-CSF supplementation influence on these targets was tested on an endometrial ex-vivo culture. Middle luteal phase endometrial biopsies were cultured on collagen sponge with or without rhG-CSF supplementation during 3 consecutive days. Variations of endometrial mRNA expression for the selected targets were studied by RT-PCR.Results
At the highest dose of rhG-CSF stimulation, the mRNA expression of these selected target genes was significantly increased if compared with their expression without addition of rhG-CSF. The selected targets were G-CSF Receptor (G-CSFR), Integrin alpha-V/beta-3 (ITGB3) implicated in cell migration and embryo implantation, Plasminogen Activator Urokinase Receptor (PLAUR) described as interacting with integrins and implicated in cell migration, Thymidine Phosphorylase (TYMP) implicated in local angiogenesis, CD40 and its ligand CD40L involved in cell proliferation control.Conclusion
RhG-CSF seems able to influence endometrial expressions crucial for implantation process involving endometrial vascular remodelling, local immune modulation and cellular adhesion pathways. These variations observed in an ex-vivo model should be tested in-vivo. The strict indications or counter indication of rhG-CSF supplementation in reproductive field are not yet established, while the safety of its administration in early pregnancy on early embryogenesis still needs to be demonstrated. Nevertheless, rhG-CSF appears as a promising therapy in some difficult and unsolved cases of reproductive failure. Indications of pre-conceptual rhG-CSF supplementation may derive from a diagnosed lack of endometrial expression of some target genes. 相似文献207.
Andrew J. J. MacIntosh Armand Jacobs Cécile Garcia Keiko Shimizu Keiko Mouri Michael A. Huffman Alexander D. Hernandez 《PloS one》2012,7(12)
In wildlife populations, group-living is thought to increase the probability of parasite transmission because contact rates increase at high host densities. Physical contact, such as social grooming, is an important component of group structure, but it can also increase the risk of exposure to infection for individuals because it provides a mechanism for transmission of potentially pathogenic organisms. Living in groups can also create variation in susceptibility to infection among individuals because circulating levels of immunosuppressive hormones like glucocorticoids often depend on an individual’s position within the group’s social structure. Yet, little is known about the relative roles of socially mediated exposure versus susceptibility in parasite transmission among free-living animal groups. To address this issue, we investigate the relationship between host dominance hierarchy and nematode parasite transmission among females in a wild group of Japanese macaques (Macaca fuscata yakui). We use social network analysis to describe each individual female’s position within the grooming network in relation to dominance rank and relative levels of infection. Our results suggest that the number of directly-transmitted parasite species infecting each female, and the relative amount of transmission stages that one of these species sheds in faeces, both increase with dominance rank. Female centrality within the network, which shows positive associations with dominance hierarchy, is also positively associated with infection by certain parasite species, suggesting that the measured rank-bias in transmission may reflect variation in exposure rather than susceptibility. This is supported by the lack of a clear relationship between rank and faecal cortisol, as an indicator of stress, in a subset of these females. Thus, socially mediated exposure appears to be important for direct transmission of nematode parasites, lending support to the idea that a classical fitness trade-off inherent to living in groups can exist. 相似文献
208.
Vrlinic T Debarnot D Legeay G Coudreuse A El Moualij B Zorzi W Perret-Liaudet A Quadrio I Mozetic M Poncin-Epaillard F 《Macromolecular bioscience》2012,12(6):830-839
New non-fouling tubes are developed and their influence on the adhesion of neuroproteins is studied. Recombinant prion proteins are considered as a single component representative of hydrophobic proteins. Samples are stored for 24?h at 4?°C in tubes coated with two different coatings: poly(N-isopropylacrylamide) as a hydrophilic surface and a plasma-fluorinated coating as a hydrophobic one. The protein adhesion is monitored by ELISA tests, XPS and confocal microscopy. It appears that the highest recovery of recombinant prion protein in the liquid phase is obtained with the hydrophilic surface while the hydrophobic character of the storage tube induces an important amount of biological loss. However, the recovery is not complete even for tubes coated with poly(N-isopropylacrylamide). 相似文献
209.
James S. Miller Adam Bradley Armand Randrianasolo Richard Randrianaivo Stephan Rakotonandrasana 《Economic botany》2005,59(3):221-230
An analysis of the taxonomic composition of 6,496 samples of plants collected for the National Cancer Institute is conducted
and the results are presented. The results show that collecting has been highly biased towards woody plant families, as these
species are often abundant, they yield samples of multiple parts, and it is often easy to collect sufficient material for
isolation of chemicals present in low concentration. Conversely, herbaceous plants that are small or grow in sparse populations
are underrepresented in collections. Three of the ten generically most diverse families in Madagascar have not been sampled,
and of these ten families, only Rubiaceae and Euphorbiaceae have had greater numbers of samples collected than predicted if
collecting was random. The causes of this bias are discussed, and solutions to ensure that bioprospecting efforts gather samples
reflective of the diversity present are presented.
Echantillonage d’une flore diverse pour des nouveaux composes biochimiques: Une Analyze des Collections de NCI Recoltees a Madagascar
Zusammenfassung Une analyze de la composition taxonomique de 6496 échantillons recoltés pour le National Cancer Institute est conduite et les resultants obtenus montrent que la récolte a été foretment biaisée, tendant pour une forte proportion des families des plantes ligneuses don’t les espèces sont souvent abondantes, peuvent fournir plusieurs sortes d’échantillon et souvent permettent facilement de collecter suffisament des matérielles pour l’isolation des composes chimiques presents à faible concentration. Contrairement, les plantes herbacées que sont de petites tailles our qui poussent avec des populations clairsemées sont sous representées dans les collections. Trois parmi les dix families génériquement les plus diversifies n’ont pas été recoltées, et de ces dix families, seules les Rubiaceae el les Euphorbiaceae ont eu les plus grands nombres d’échantillons que prévus si la récolte a été fait au hazard. Les cause de cette disproportion sont discutées et les solutions pour assurer que les efforts de bioprospection rassemblent des échantillons reflétant la diversité présente sont presentées.相似文献
210.
Benoist M Baude A Tasmadjian A Dargent B Kessler JP Castets F 《Journal of neurochemistry》2008,106(2):969-977
Members of the striatin family are scaffolding proteins involved in numerous signaling pathways principally in neurons. Zinedin is the only member of this protein family for which the brain distribution has not been determined so far. Here, we have validated a specific antibody against zinedin and used this tool to study the localization of zinedin at cellular and sub-cellular levels in the rat brain. Zinedin is primarily expressed in neurons of the hippocampus, cerebral cortex, olfactory bulb and caudate putamen nucleus. Like other members of the striatin family, zinedin displays a polarized distribution in the somato-dendritic compartment of neurons and is enriched in dendritic spines. The rostral expression of zinedin as well as its compartmented distribution in dendritic spines may have important implications not only for zinedin function but also in the physiology of dendritic spines of a particular subset of neurons. 相似文献