Establishment and analysis of a reference transcriptome for Spodoptera frugiperda

International audienceBackground Spodoptera frugiperda (Noctuidae) is a major agricultural pest throughout the American continent. The highly polyphagous larvae are frequently devastating crops of importance such as corn, sorghum, cotton and grass. In addition, the Sf9 cell line, widely used in biochemistry for in vitro protein production, is derived from S. frugiperda tissues. Many research groups are using S. frugiperda as a model organism to investigate questions such as plant adaptation, pest behavior or resistance to pesticides.ResultsIn this study, we constructed a reference transcriptome assembly (Sf_TR2012b) of RNA sequences obtained from more than 35 S. frugiperda developmental time-points and tissue samples. We assessed the quality of this reference transcriptome by annotating a ubiquitous gene family - ribosomal proteins - as well as gene families that have a more constrained spatio-temporal expression and are involved in development, immunity and olfaction. We also provide a time-course of expression that we used to characterize the transcriptional regulation of the gene families studied.ConclusionWe conclude that the Sf_TR2012b transcriptome is a valid reference transcriptome. While its reliability decreases for the detection and annotation of genes under strong transcriptional constraint we still recover a fair percentage of tissue-specific transcripts. That allowed us to explore the spatial and temporal expression of genes and to observe that some olfactory receptors are expressed in antennae and palps but also in other non related tissues such as fat bodies. Similarly, we observed an interesting interplay of gene families involved in immunity between fat bodies and antennae

Proceedings from the 2018 Canadian Association for the Study of the Liver Single Topic Conference—Decompensated Cirrhosis : from clinic to transplant

Actes publiés dans le Canadian Liver Journal; vol. 2, no. 4, Fall 2019, p. 137-170

Physical training in boys with Duchenne Muscular Dystrophy: the protocol of the No Use is Disuse study

Contains fulltext : 89740.pdf (publisher's version ) (Open Access)BACKGROUND: "Use it or lose it" is a well known saying which is applicable to boys with Duchenne Muscular Dystrophy (DMD). Besides the direct effects of the muscular dystrophy, the increasing effort to perform activities, the fear of falling and the use of personal aids indirectly impair leg and arm functions as a result of disuse. Physical training could oppose this secondary physical deterioration. The No Use is Disuse (NUD) study is the first study in human subjects with DMD that will examine whether a low-intensity physical training is beneficial in terms of preservation of muscle endurance and functional abilities. The study consists of two training intervention studies: study 1 "Dynamic leg and arm training for ambulant and recently wheelchair-dependent boys with DMD and, study 2 "Functional training with arm support for boys with DMD who have been confined to a wheelchair for several years". This paper describes the hypotheses and methods of the NUD study. METHODS: Study 1 is an explorative randomized controlled trial with multiple baseline measurements. Thirty boys with a DNA-established diagnosis of DMD will be included. The intervention consists of a six-months physical training during which boys train their legs and arms with active and/or assisted cycling training equipment. The primary study outcomes are muscle endurance and functional abilities, assessed with a Six-Minute Bicycle Test and the Motor Function Measure. Study 2 has a within-group repeated measurements design and will include ten boys with DMD who have already been confined to a wheelchair for several years. The six-months physical training program consists of 1) a computer-assisted training and 2) a functional training with an arm support. The primary study outcome is functional abilities of the upper extremity, assessed with the Action Research Arm Test. DISCUSSION: The NUD study will fill part of the gap in the current knowledge about the possible effects of training in boys with DMD and will increase insight into what type of exercise should be recommended to boys with DMD. The study will finish at the end of 2010 and results are expected in 2011. TRIAL REGISTRATION: The Netherlands National Trial Register1631

Et si la recherche scientifique ne pouvait pas être neutre?

Les manières de faire de la science aujourd’hui sont multiples et innovantes. Pourtant, un modèle normatif continue d’écraser les autres : le modèle positiviste. Il soutient que la science vise l’étude objective de la réalité en s’appuyant sur l’application rigoureuse de la méthode « scientifique » dont la neutralité est un des emblèmes. Cette vision est vivement contestée dans plusieurs champs de recherche, tels que les études sociales des sciences, l’histoire des sciences et les études féministes et décoloniales. Ces critiques considèrent que les théories scientifiques sont construites et influencées par le contexte social, culturel et politique dans lequel travaillent les scientifiques, ainsi que par les conditions matérielles de leur travail. Cet ancrage social de la science rend impensable, pour ces critiques, l’idée même de neutralité. Faut-il donc renoncer à cette exigence normative? Par quelle autre norme la remplacer? Né d’un colloque tenu en 2017 à Montréal, ce livre propose les réflexions et analyses de 25 auteurs et autrices issues de sept pays sur ces questions. Études de cas, analyses réflexives et discussions théoriques s’entrecroisent pour permettre une réflexion collective approfondie sur ces enjeux anciens, mais constamment renouvelés, notamment dans le contexte du nouveau statut précaire de l’expertise scientifique dans l’espace public

Investigating Legionella pneumophila physicochemical surface properties to explore potential determinants in host cells adhesion

International audienceBacteria have complex parietal structures in direct contact with the medium,which constitute a zone of exchanges with their local environments. Recent studies on physicochemistry of the bacterial interfaces have highlighted that physical properties (viscoelasticity, hydrophobicity) and electrokinetic ones (charge density, hydrodynamic permeability) are crucial determinants in bacterial adhesion processes (1).In this context, the physicochemical surface properties (charge and hydrophobicity) of the human pathogenic bacteria, Legionella pneumophila sg1 (Lp1) were investigated to explore the initial interaction step during host cells-bacteria interactions.The bio-interfaces of different clinical L. pneumophila strains and also four mutants deficient in some parietal structures (pili, lipopolysaccharides) were characterized at the micrometer scale using microelectrophoresis and at nanometer scale by atomic force microscopy (AFM) (2). The first allowed to measure electrophoretic mobilities (electrostatic interactions) and the second to quantify local hydrophobicity and specific adhesion interactions of surface biopolymers. The impact of different ionic strenghts (1 to 100 mM) at neutral pH of the medium on the physicochemical properties and infection capacity were investigated.Our results showed that initial long-range repulsive forces could possibly play an important role in defining the adhesion/infection process. The LPS nature of the Lp1 strains contributed to their negative electrical charge and consequently to their electrophoretic mobilities. Complementary informations, particularly the cell surface imaging (presence of flagella and pili) and mapping the hydrophobic domains of cells, were performed with AFM on the Lp1 strains with contrasted mobility patterns. These data should lay the molecular basis of the L. pneumophila adhesion mechanisms to host cells

Heterogeneous Fenton's reaction : a promising way for drinking water biofilm disinfection

International audienceOne of the most promising methods emerging from the European FP7 project SecurEau for drinking water distribution system disinfection is based on Fenton's reaction. This reaction appears as a non‐expensive and friendly environmental method. The process is known to generate powerful oxidative species as hydroxyl radicals HO. through a succession of reactions involving iron and hydrogen peroxide at acidic pH

Particle Counting for Early Detection of Contaminants in Drinking Water

International audienceAs pointed out for many years there is a flux of particles in drinking water distribution systems which may originate from the treatment plant itself or may be generated in the distribution system (biofilm sloughing, sediment resuspension, flocculation, …). Most of these particles are below 50 µm with an average size of 5 µm. These particles, which are easy to mobilise by a water flow above normal and generally consist of iron (60%) and organic matter (20%)

Assessment of low magnetic electric fields on drinking water biofilm formation

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Physicochemical surface properties: the microelectrophoresis approach

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An <em>ex vivo</em> murine model to study poliovirus-induced apoptosis in nerve cells

International audienceParalytic poliomyelitis results from destruction of motor neurons owing to poliovirus (PV) replication. Using a mouse model, we have previously shown that PV kills neurons of the central nervous system (CNS) as a result of apoptosis (Girard et al., Journal of Virology 73, 6066-6072, 1999). We report the development of mixed mouse primary nerve cell cultures from the cerebral cortex of neonatal mice transgenic for the human PV receptor. These cultures contained all three main cell types of the CNS, i.e. neurons, astrocytes and oligodendrocytes. All three cell types were susceptible to PV infection and virus replication in the cultures led to DNA fragmentation characteristic of apoptosis. PV-induced apoptosis was inhibited by the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp(O-Me) fluoromethyl ketone (Z-VAD.FMK), indicating that this process involved caspases. Thus, these mixed mouse primary nerve cell cultures are a new in vitro model for studying the molecular mechanisms of PV-induced apoptosis in nerve cells