eKhSACIR інституційному репозитарії Харківської державної академії культури
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Associations entre profils métabolomiques plasmatiques rmn et composition du microbiote intestinal au sein d’une population d’adultes francais en bonne santé
No full textNational audienceLe co-métabolisme hôte-microbiote est à l’origine d’un très grand nombre de molécules intégrées au sein d’axes métaboliques complexes. De nombreuses études se sont attachées à la caractérisation fonctionnelle spécifique de certaines de ces molécules (AGCC, BCAA, TMAO, etc.), mais les études envisageant plus globalement les relations métaboliques entre l’hôte et son microbiote intestinal restent rares. À ce titre, l’étude globale des métabolites endogènes et exogènes présents dans le plasma par métabolomique non ciblée semble prometteuse
Detection and characterization of the feed intake response of growing pigs to perturbations
No full textInternational audienceImproving robustness for farm animals is seen as a new breeding target. However, robustness is a complex trait and not measurable directly. Robustness can be characterized by examining the animal’s response to environmental perturbations. Although the origin of environmental perturbations may not be known, the effect of a perturbation on the animal can be observed, for example through changes in voluntary feed intake. We developed a generic model and data analysis procedure to detect these perturbations, and subsequently characterize the feed intake response of growing pigs in terms of resistance and resilience as elements of robustness when faced with perturbations. We hypothesize that there is an ideal trajectory curve of cumulative feed intake, which is the amount of feed that a pig desires to eat when it is not facing any perturbation. Deviations from this ideal trajectory curve are considered as a period of perturbation, which can be characterized by its duration and magnitude. It is also hypothesized that, following a perturbation, animals strive to regain the ideal trajectory curve. A model based on differential equations was developed to characterize the animal’s response to perturbations. In the model, a single perturbation can be characterized by two parameters which describe the resistance and resilience potential of the animal to the perturbing factor. One parameter describes the immediate reduction in daily feed intake at the start of the perturbation (i.e. a ‘resistance’ trait) while another describes the capacity of the animal to adapt to the perturbation through compensatory feed intake to rejoin the ideal trajectory curve (i.e. a ‘resilience’ trait). The model has been employed successfully to identify the ideal trajectory curve of cumulative feed intake in growing pigs and to quantify the animal’s response to a perturbation by using feed intake as the response criterion. Further developments include the analysis of individual feed intake curves of group-housed pigs that can be exposed to the same environmental perturbing factors to quantify and to compare different pigs. This study is part of the Feed-a-Gene project and was funded by the European Union under grant agreement no. 633531
Daptomycin failure to treat S. aureus biofilms: contribution of multimodal fluorescence micro/nanoscopy techniques
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Accompagner les transformations du travail des agriculteurs, animateurs, enseignants, et chercheurs dans le cadre de la transition agroécologique : le projet de recherche-action TRANSAE
No full textSession : Le travail sous toutes ses formesNational audienceThe agroecological transition rings on transormations of farmers', animators, researchers, advisors' and teachers' works in their different dimensions. The TRANSAE project (Work Transformations and Transitions to Agro-Ecology) is constructed according to a community of practices aimed at supporting the transformations of these actors' work in the framework of the agroecological transition. This project is manage closed to the way CIVAM networks work : farmers and animators of the project are involved in the CIVAM networks. TRANSAE's animation is based on (i) the supply of tools to the actors to accompagny the transformation of work, to transform their own work situation and (ii) the pooling and tracing of feedbacds. Beyond the co-construction of common methods, practices, and tools, this research-action project management allows the actors to focus on the concrete activity, its course, its organization, its meanings, its determinants and its effects on farms and on workers. The entrance by the activity transforms the ways of thinking and practicing the accompaniment, the teaching and the research : it gives ways of improvement of their daily life to the farmers.La transition agroécologique se manifeste par des transformations du travail de l'agriculteur, des accompagnateurs, des chercheurs, des conseillers et enseignants dans ses différentes dimensions. Le projet TRANSAE (TRANSformations du TRAvail et TRANSitions vers l'Agro-Ecologie) est conduit selon une communauté de pratiques visant à accompagner les transformations du travail de ces acteurs dans le cadre de la transition agroécologique. Cette conduite de projet est proche du mode de fonctionnement des réseaux CIVAM qui réunissent les agriculteurs et animateurs de TRANSAE. L'animation est basée sur (i) l'outillage des acteurs pour accompagner les transformations du travail, transformer leur propre situation de travail et (ii) la mutualisation et le traçage des retours d'expérience. Au delà de la co-construction de méthodes, de pratiques et d'outils communs, cette conduite de projet recherche-action permet aux acteurs de se centrer sur l'activité concrète, son déroulement, son organisation, son sens, ses déterminants et es effets sur l'exploitation et sur les personnes. L'entrée par l'activité transforme les façons de penser et de pratiques l'accompagnement, l'enseignement et la recherche : elle donne des pistes d'amélioration de leur quotidien aux agriculteurs
Is skeletal muscle remodeling associated with gut microbiota signature?
No full textInternational audienceBacteria sheltered in gut impact on the physiology and function of several distant organs such as liver, adipose tissue or brain1. A functional cross talk between gut microbiota and skeletal muscle has also been recently discussed in the literature2. However this hypothesis requires more experimental support. Here we investigated in mice whether skeletal muscle remodeling could affect gut microbiota signature and pertinent intestinal mRNA genes expression related to muscle metabolism. We showed that mice invalidated for myostatin, a lean model presenting hypertrophic fatigable muscles3,4, display a specific microbiota signature characterized notably by a decrease of Firmicutes and Proteobacteria phyla. We also highlighted in the distal intestine an over-expression of Fiaf mRNA, a fat storage inhibitor5 and this could contribute to the specific lean phenotype of myostatin KO mice. Furthermore, 4 weeks of aerobic endurance training was associated with a normalization of gut microbiota signature (and phyla abundance) of KO-myostatin mice towards the WT profile. Interestingly, we also observe a normalization of expression of some intestinal mRNA markers including Fiaf. Altogether our results suggest a cross-talk between muscle remodeling and gut microbiota. Further understanding of the underlying mechanisms could open new therapeutic strategies for muscle- related disorders
La fromageabilité du lait en race Montbéliarde dans les élevages AOP et IGP de Franche- Comté : variabilité et facteurs de variation
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Effets de la supplémentation alimentaire en arginine chez les juments gravides sur le métabolisme maternal, la fonction placentaire et le poids de naissance des poulains
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Effects of a fungicide on oligochaetes and soil organic matter dynamics under controlled conditions
No full textInternational audiencePesticides are used in agriculture to protect crops and ensure satisfying yields. However, theycan affect non-target organisms and the related ecological functions (e.g. organic matterdecomposition, soil structure). Earthworms (macrofauna > 2 mm in diameter) and enchytraeids(mesofauna 0.2 mm in diameter) are Annelida Oligochaeta involved in organicmatter transformation. These organisms are considered as ecosystem engineers because theymodify environmental conditions for other organisms through their bioturbation activity. Forexample, Huang and Xia (2018) had shown that earthworm mucus promoted microbial activitythat increased organic matter mineralization by specific bacteria. If this process has been quitewell studied for earthworms, much less is known about the effects of enchytraeids on soilorganic matter dynamics, and even less after pesticide applications.We conducted a laboratory experiment with a natural soil to test the assumption that theapplication of a commercial formulation of fungicide (Swing® Gold, composed of 50 g.l-1epoxiconazole and 133 g.l-1 dimoxystrobin) would lead to direct effects on terrestrialOligochaeta (mortality, weight gain) and indirect effects on organic matter mineralization (CO2release). We also tested whether these effects were in the same magnitude for earthworms andenchytraeids. For that, we used different concentrations of fungicide (no fungicide, one, andthree times the recommended dose RD) and four conditions related to soil fauna (no fauna,earthworms Aporrectodea caliginosa alone, enchytraeids Enchytraeus buchholzi alone, a mix ofearthworms and enchytraeids) during 26 days. To estimate the mineralization of organic matter,CO2 release was measured at days 1, 5, 8, 12, 15, 19, 22 and 26. The total mineralization wascalculated on the entire experiment duration. For trapping CO2, NaOH was placed in a dish andinserted in each microcosm for 24 hours, then titrated with HCl to determine the CO2 content.No mortality was recorded at the end of the experiment, whatever the treatment. We foundno significant effect of the pesticide on animal weight gain. Organic matter mineralizationdecreased with increasing concentration of pesticide until day 19. After this period, the contraryoccurred since the release of CO2 was higher in the treatments with the fungicide at 3 times theRD than in treatments at the RD and without fungicide. This can be explained by some bacteriaspecies which can use pesticides as energy sources, thus enhancing their activities, such asmineralization. Fauna assemblage had no effect on mineralization until day 22. Then, CO2release was higher when earthworms or enchytraeids were present (no difference between thesetreatments) than in the treatment without animals. The treatment involving earthworms andenchytraeids had a middle level of mineralization. This could be explained by a competitionbetween earthworms and enchytraeids for food resources.At the end of the experiment, the highest mineralization rate was recorded in the treatmentwith earthworms and without pesticide. This result confirms the positive role of earthworms insoil organic matter mineralization. We also found an effect of the interaction between thepesticide and fauna treatments on mineralization at days 19 and 22. With no pesticide,enchytraeids were less efficient than earthworms but, probably withstanding higher pesticidecontamination, they displayed a higher rate of mineralization than earthworms in conditionswith pesticide at 1 and 3 times the RD
Zymoseptoria tritici histone modifications distinguish core and accessory chromosomes and play an important role in genome stability
No full textInternational audienceZymoseptoria tritici is a fungal pathogen of wheat. The genome of the reference isolate comprises 21 chromosomes of which eight are accessory. These chromosomes are not key determinants for virulence, as in other fungal pathogens, however, they are partly conserved among distinct Zymoseptoria species. Accessory chromosomes are highly instable during meiosis and mitosis, transcriptionally repressed and show enrichment of repetitive elements and heterochromatic histone marks. To elucidate if heterochromatic histone modifications have an impact on chromosome stability, we created deletion mutants of the methyltransferases responsible for H3K27me3 and H3K9me3. H3K27me3 is specifically associated with accessory chromosomes and subtelomeric regions in Z. tritici, while H3K9me3 is associated with repetitive elements. We combined experimental evolution, genetic and highresolution microscopic analyses to follow the impact of these deletions on chromosome and genome stability. We used ChIP-seq, genome sequencing and RNA-seq to compare changes in chromatin and genome structure and differences in gene expression between mutant and wild type strains. The loss of H3K9me3 results in dramatic chromatin reorganization, transposable element activation, genome rearrangements, formation of “neochromosomes” and increased accessory chromosome instability. Loss of H3K27me3, however, has little effect on chromatin organization and transposon control, but increases stability of the accessory chromosomes. We conclude that H3K9me3 strongly impacts chromatin and genome organization and that H3K27me3 has an important role in stability of accessory chromosomes. Epigenetic regulation is an important driver of genome evolution in this fungus and can contribute to rapid adaptation