160 research outputs found

    Composite Phaseolus vulgaris plants with transgenic roots as research tool

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    Large seeded grain legumes such as the common bean (Phaseolus vulgaris) and cowpea (Vigna unguiculata) are very important crops with seeds that are major protein source for people in developingcountries, but their yields and improvement lag behind the economically more important cereals. For research purposes, genetic transformation is a powerful tool to obtain valuable information on gene expression and putative gene functions. In addition, through genetic transformation, candidate genes can be evaluated for their potential in agricultural biotechnology applications, such as resistance against biotic stresses. However, it remains difficult to stable genetically transform large seeded grain legumes such as Phaseolus and cowpea using Agrobacterium tumefaciens. In this paper a system is described to obtain so-called transgenic composite plants from P. vulgaris. These have a transgenic root system, obtained through Agrobacterium rhizogenes transformation of de-rooted seedlings. Their potentials for studies on important processes in the root system will be discussed

    Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic

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    The remineralisation of sinking particles by prokaryotic heterotrophic activity is important for controlling oceanic carbon sequestration. Here, we report mesopelagic particulate organic carbon (POC) remineralisation fluxes in the North Atlantic along the GEOTRACES-GA01 section (GEOVIDE cruise; May-June 2014) using the particulate biogenic barium (excess barium; Baxs/ proxy. Important mesopelagic (100-1000 m) Baxs differences were observed along the transect depending on the intensity of past blooms, the phytoplankton community structure, and the physical forcing, including downwelling. The subpolar province was characterized by the highest mesopelagic Baxs content (up to 727 pmol L-1/, which was attributed to an intense bloom averaging 6 mg chl a m-3 between January and June 2014 and by an intense 1500m deep convection in the central Labrador Sea during the winter preceding the sampling. This downwelling could have promoted a deepening of the prokaryotic heterotrophic activity, increasing the Baxs content. In comparison, the temperate province, characterized by the lowest Baxs content (391 pmol L-1/, was sampled during the bloom period and phytoplankton appear to be dominated by small and calcifying species, such as coccolithophorids. The Baxs content, related to oxygen consumption, was converted into a remineralisation flux using an updated relationship, proposed for the first time in the North Atlantic. The estimated fluxes were of the same order of magnitude as other fluxes obtained using independent methods (moored sediment traps, incubations) in the North Atlantic. Interestingly, in the subpolar and subtropical provinces, mesopelagic POC remineralisation fluxes (up to 13 and 4.6 mmol Cm-2 d-1, respectively) were equalling and occasionally even exceeding upper-ocean POC export fluxes, deduced using the 234Th method. These results highlight the important impact of the mesopelagic remineralisation on the biological carbon pump of the studied area with a near-zero, deep (> 1000 m) carbon sequestration efficiency in spring 2014

    Оцінка якості життя у вікових першовагітних та вагітних з великим інтергенетичним інтервалом

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    Проведено изучение показателей качества жизни у 120 возрастных первобеременных и 240 беременных с большим интергенетическим интервалом с использованием опросника SF-36 Health Status Survey, разработанного The Health Institute, New England Medical Center, Boston, USA. Исследование показало, что пациентки обеих групп имеют низкие показатели качества жизни. При сравнении большинство изучаемых параметров оценки качества жизни в обследованных группах не отличались, однако у пациенток с большим интергенетическим интервалом – достоверно выше оценка социальной роли и энергетичности. Оценка качества жизни у возрастных первобеременных и беременных с большим интергенетическим интервалом является важным сегментом наблюдения во время беременности, который оценивает перспективы развития беременности в психологическом, физическом и социальном аспектах.A study of the life quality of 120 over-age primigravidas and of 240 women with a large intergenetic interval has been carried out using the questionnaire SF-36 Health Status Survey developed by The Health Institute, New England Medical Center, Boston, USA. This research has shown that the patients in the both groups have a low quality of life. The major part of the life quality parameters were the same in the both groups, however, in patients with a large interval between births the values of the social role and the energy level were significantly higher. The life quality of over-age primigravidas and pregnant women with a large interval between successive births is an important sector of observation during pregnancy, which allows assessing the prospects of pregnancy in the psychological, physical, and social aspects

    The Terebridae and teretoxins: Combining phylogeny and anatomy for concerted discovery of bioactive compounds

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    The Conoidea superfamily, comprised of cone snails, terebrids, and turrids, is an exceptionally promising group for the discovery of natural peptide toxins. The potential of conoidean toxins has been realized with the distribution of the first Conus (cone snail) drug, Prialt (ziconotide), an analgesic used to alleviate chronic pain in HIV and cancer patients. Cone snail toxins (conotoxins) are highly variable, a consequence of a high mutation rate associated to duplication events and positive selection. As Conus and terebrids diverged in the early Paleocene, the toxins from terebrids (teretoxins) may demonstrate highly divergent and unique functionalities. Recent analyses of the Terebridae, a largely distributed family with more than 300 described species, indicate they have evolutionary and pharmacological potential. Based on a three gene (COI, 12S and 16S) molecular phylogeny, including ~50 species from the West-Pacific, five main terebrid lineages were discriminated: two of these lineages independently lost their venom apparatus, and one venomous lineage was previously unknown. Knowing the phylogenetic relationships within the Terebridae aids in effectively targeting divergent lineages with novel peptide toxins. Preliminary results indicate that teretoxins are similar in structure and composition to conotoxins, suggesting teretoxins are an attractive line of research to discover and develop new therapeutics that target ion channels and receptors. Using conotoxins as a guideline, and innovative natural products discovery strategies, such as the Concerted Discovery Strategy, the potential of the Terebridae and their toxins are explored as a pioneering pharmacological resource

    Novel conditionally immortalized human proximal tubule cell line expressing functional influx and efflux transporters

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    Reabsorption of filtered solutes from the glomerular filtrate and excretion of waste products and xenobiotics are the main functions of the renal proximal tubular (PT) epithelium. A human PT cell line expressing a range of functional transporters would help to augment current knowledge in renal physiology and pharmacology. We have established and characterized a conditionally immortalized PT epithelial cell line (ciPTEC) obtained by transfecting and subcloning cells exfoliated in the urine of a healthy volunteer. The PT origin of this line has been confirmed morphologically and by the expression of aminopeptidase N, zona occludens 1, aquaporin 1, dipeptidyl peptidase IV and multidrug resistance protein 4 together with alkaline phosphatase activity. ciPTEC assembles in a tight monolayer with limited diffusion of inulin-fluorescein-isothiocyanate. Concentration and time-dependent reabsorption of albumin via endocytosis has been demonstrated, together with sodium-dependent phosphate uptake. The expression and activity of apical efflux transporter p-glycoprotein and of baso-lateral influx transporter organic cation transporter 2 have been shown in ciPTEC. This established human ciPTEC expressing multiple endogenous organic ion transporters mimicking renal reabsorption and excretion represents a powerful tool for future in vitro transport studies in pharmacology and physiology

    Functional genomic approaches to study and engineer secondary metabolism in plant cell cultures

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    Plants produce a wide range of secondary compounds, also referred to as natural products, which may have important functions in the plants adaptation to specific ecological niches or its responses to biotic and abiotic stresses. Some of these secondary metabolites turn out to be beneficial for humans as pharmaceuticals. Because of their unique and often complex chemical structures, synthesis of these natural compounds is frequently unfeasible or not economically justified. Therefore, many secondary metabolites are still extracted from whole plants. However, they are often produced only in certain tissues, at specific developmental stages or they are present in low concentrations. The possibility of growing medicinal plants, either as a whole, or as a specific tissue or even as plant cells in so-called tissue culture is intensively being investigated. Nevertheless, only few examples of commercial exploitation of plant cell cultures to produce a natural product exist, mainly due to the low yields and the instability of production rates commonly encountered in cell culture systems. Emerging tools such as metabolic engineering have added little to the production problem, since insight into the molecular mechanisms driving plant secondary metabolism at present is fairly limited. Knowledge of the genetics of biosynthetic pathways and their regulation is thus of crucial importance to bypass the low yield of various secondary metabolites in plant cells. To facilitate gene discovery in plant secondary metabolism, in our department a comprehensive profiling approach has been developed that is based on functional genomics. This approach integrates cDNA-AFLP-based transcript profiling and targeted metabolic profiling. As this method requires no prior genetic knowledge or sequence databanks, it is applicable to any plant species to unravel the biosynthesis of any metabolite of interest. This knowledge will then allow for metabolic engineering, as well as pave the way for so-called ‘combinatorial biochemistry’, with which novel metabolites could be produced in plant

    Analysis of a Nicotiana plumbaginifolia cDNA encoding a novel small GTP-binding protein

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    AbstractSmall GTP-binding proteins belonging to the Ras superfamily have been found in evolutionarily divergent organisms. Here, we report the isolation and analysis of a cDNA encoding a putative small GTP-binding protein, designated Rhn1, from the plant, Nicotiana plumbaginifolla. The 21.8-kDa protein has 60% amino acid similarity with the mammalian Rab5 proteins. The Rhn1 protein is encoded by a small multigene family. Northern analysis shows the highest steady-state mRNA levels to be in roots and flowers. Furthermore, the Rhnl protein has 80% amino acid similarity with an Arabidopsis small GTP-binding protein, designated Rha1
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