Pratiques agricoles pour la réduction des produits phytosanitaires. le rôle de l’apprentissage collectif

En partant d’une expérience multi-partenariale originale de MAET-DCE portée par une coopérative, ce travail se propose d’analyser le rôle de l’apprentissage collectif sur la réduction des risques liés à l’adoption de pratiques agricoles alternatives. Le processus de transmission de l’information technique ainsi que les formes de coordination associées ont été analysés en mobilisant des approches principalement de l’économie institutionnelle traitant de l’incertitude et des modalités actuelles du conseil en agriculture. L’analyse montre que l’action de la coopérative est au centre de la création conjointe de plusieurs catégories de biens, reposant sur différents types de transaction informationnelle.Based on an original multi-partnership experience of agri-environmental measure (MAET-DCE) carried by a cooperative, this study aims to analyse the role of collective learning on the reduction of risks associated with the adoption of alternative agricultural practices. The process of transmission of technical information and the associated forms of coordination have been analysed using a conceptual framework inspired by works done in institutional economics on uncertainty and extension service in agriculture. The analysis shows that the cooperative is at the center of the joint production of different categories of goods, based on different types of informational transactions

Régulation de la protéine découplante UCP3 et inhibition génique ou pharmacologique de la lipase hormono-sensible

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Rôle de l'apprentissage collectif dans l'adoption de pratiques agricoles visant à réduire l'utilisation de pesticides : une approche par les coûts de transaction appliquée à l'adoption d'une MAET-DCE sur le bassin versant Adour-Garonne

National audienceAdoption of pesticides reducing agricultural practices. The role of collective learning Based on an original multi-partnership experience of agri-environmental measure (MAET-DCE) carried by a cooperative, this study aims to analyse the role of collective learning on the reduction of risks associated with the adoption of alternative agricultural practices. The process of transmission of technical information and the associated forms of coordination have been analysed using a conceptual framework inspired by works done in institutional economics on uncertainty and extension service in agriculture. The analysis shows that the cooperative is at the center of the joint production of different categories of goods, based on different types of informational transactionsLe dernier rapport d'expertise de l'INRA-CEMAGREF met en avant la nécessité, d'une part, de référencer les différentes pratiques alternatives utiles pour réduire les impacts environnementaux liés à l'emploi de pesticides, et d'autre part, de considérer les conditions d'adoption et de mise en oeuvre de ces pratiques tant au niveau de l'exploitation agricole qu'au niveau de son environnement économique et social. Notre étude s'inscrit dans le cadre d'un projet de recherche PSDR/CCRDT Midi-Pyrénées visant à analyser les conditions d'adoption de techniques alternatives et innovantes en matière d'utilisation de phytosanitaires en agriculture. Nous nous sommes intéressés plus précisément au processus de la transmission de l'information technique qui accompagne la mise en oeuvre d'un projet innovant de MAET-DCE portée par une coopérative située sur un bassin versant de Midi-Pyrénées. Ce processus en cours a été analysé en mobilisant l'économie institutionnaliste. Pour aborder la question de la gestion des risques d'adoption des nouvelles pratiques par les acteurs parties prenantes nous avons préalablement mobilisé des approches traitant de l'incertitude (typologie des situations d'incertitude) et des modalités actuelles du conseil en agriculture (cadrage technique). Du point de vue économique et à partir du cas étudié, nous avons proposé une nouvelle interprétation des phénomènes pouvant avoir lieu lors de la mise en oeuvre des politiques environnementales visant le changement des pratiques de production et touchant de fait un ensemble de partenaires comme ceux intervenant dans une filière de production agroalimentaire. L'action de la coopérative est au centre de la création conjointe de plusieurs catégories de biens via plusieurs types des coordinations entre les acteurs concernés, individuels, collectifs ou d'organismes privés ou publics. Ce type de production jointe va au delà des phénomènes déjà identifiée dans la littérature économique à propos de la multifonctionnalité de l'agriculture et la gestion des ressources naturelles en général. Ils concernent plus particulièrement les processus d'apprentissage et la création multi-partenariale de connaissances nécessaires au changement technique mais aussi institutionnel qui est proposé ou imposé dans une optique de développement durable

Transcription of the human uncoupling protein 3 gene is governed by a complex interplay between the promoter and intronic sequences.

International audienceAIMS/HYPOTHESIS: Uncoupling protein (UCP) 3 is an inner mitochondrial membrane transporter mainly produced in skeletal muscle in humans. UCP3 plays a role in fatty acid metabolism and energy homeostasis and modulates insulin sensitivity. In humans, UCP3 content is higher in fast-twitch glycolytic muscle than in slow-twitch oxidative muscle and is dysregulated in type 2 diabetes. Here, we studied the molecular mechanisms determining human UCP3 levels in skeletal muscle and their regulation by fasting in transgenic mice. METHODS: We produced a series of transgenic lines with constructs bearing different putative regulatory regions of the human UCP3 gene, including promoter and intron sequences. UCP3 mRNA and reporter gene expression and activity were measured in different skeletal muscles and tissues. RESULTS: The profile of expression and the response to fasting and thyroid hormone of human UCP3 mRNA in transgenic mice with 16 kb of the human UCP3 gene were similar to that of the endogenous human gene. Various parts of the UCP3 promoter did not confer expression in transgenic lines. Inclusion of intron 1 resulted in an expression profile in skeletal muscle that was identical to that of human UCP3 mRNA. Further dissection of intron 1 revealed that distinct regions were involved in skeletal muscle expression, distribution among fibre types and response to fasting. CONCLUSIONS/INTERPRETATION: The control of human UCP3 transcription in skeletal muscle is not solely conferred by the promoter, but depends on several cis-acting elements in intron 1, suggesting a complex interplay between the promoter and intronic sequences

Hit-and-Run Epigenetic Editing for Vectors of Snail-Borne Parasitic Diseases

Snail-borne parasitic diseases represent an important challenge to human and animal health. Control strategies that target the intermediate snail host has proved very effective. Epigenetic mechanisms are involved in developmental processes and therefore play a fundamental role in developmental variation. DNA methylation is an important epigenetic information carrier in eukaryotes that plays a major role in the control of chromatin structure. Epigenome editing tools have been instrumental to demonstrate functional importance of this mark for gene expression in vertebrates. In invertebrates, such tools are missing, and the role of DNA methylation remains unknown. Here we demonstrate that methylome engineering can be used to modify in vivo the CpG methylation level of a target gene in the freshwater snail Biomphalaria glabrata, intermediate host of the human parasite Schistosoma mansoni. We used a dCas9-SunTag-DNMT3A complex and synthetic sgRNA to transfect B. glabrata embryos and observed an increase of CpG methylation at the target site in 50% of the hatching snails

Transcriptional control of brown fat determination by PRDM16.

International audienceBrown fat cells are specialized to dissipate energy and can counteract obesity; however, the transcriptional basis of their determination is largely unknown. We show here that the zinc-finger protein PRDM16 is highly enriched in brown fat cells compared to white fat cells. When expressed in white fat cell progenitors, PRDM16 activates a robust brown fat phenotype including induction of PGC-1alpha, UCP1, and type 2 deiodinase (Dio2) expression and a remarkable increase in uncoupled respiration. Transgenic expression of PRDM16 at physiological levels in white fat depots stimulates the formation of brown fat cells. Depletion of PRDM16 through shRNA expression in brown fat cells causes a near total loss of the brown characteristics. PRDM16 activates brown fat cell identity at least in part by simultaneously activating PGC-1alpha and PGC-1beta through direct protein binding. These data indicate that PRDM16 can control the determination of brown fat fate

Testis hormone-sensitive lipase expression in spermatids is governed by a short promoter in transgenic mice

A testicular form of hormone-sensitive lipase (HSLtes), a triacylglycerol lipase, and cholesterol esterase, is expressed in male germ cells. Northern blot analysis showed HSLtes mRNA expression in early spermatids. Immunolocalization of the protein in human and rodent seminiferous tubules indicated that the highest level of expression occurred in elongated spermatids. We have previously shown that 0.5 kilobase pairs of the human HSLtes promoter directs testis-specific expression of a chloramphenicol acetyltransferase reporter gene in transgenic mice and determined regions binding nuclear proteins expressed in testis but not in liver (Blaise, R,, Grober, J,, Rouet, P., Tavernier, G., Daegelen, D., and Langin, D. (1999) J. Biol. Chem. 274, 9327-9334). Mutation of a SRY/Sox-binding site in one of the regions did not impair in vivo testis-specific expression of the reporter gene. Further transgenic analyses established that 95 base pairs upstream of the transcription start site were sufficient for correct testis expression. In gel retardation assays using early spermatid nuclear extracts, a germ cell-specific DNA-protein interaction was mapped between -46 and -29 base pairs. The DNA binding nuclear protein showed properties of zinc finger transcription factors. Mutation of the region abolished reporter gene activity in transgenic mice, showing that it is necessary for testis expression of HSLtes

Resistance to high-fat-diet-induced obesity and sexual dimorphism in the metabolic responses of transgenic mice with moderate uncoupling protein 3 overexpression in glycolytic skeletal muscles.

0012-186X (Print) 0012-186X (Linking) Journal Article Research Support, Non-U.S. Gov'tInternational audienceAIMS/HYPOTHESIS: Uncoupling protein (UCP) 3 is a mitochondrial inner membrane protein expressed predominantly in glycolytic skeletal muscles. Its role in vivo remains poorly understood. The aim of the present work was to produce a mouse model with moderate overproduction and proper fibre-type distribution of UCP3. METHODS: Transgenic mice were created with a 16 kb region encompassing the human UCP3 gene. Mitochondrial uncoupling was investigated on permeabilised muscle fibres. Changes in body weight, adiposity and glucose or insulin tolerance were assessed in mice fed chow and high-fat diets. Indirect calorimetry was used to determine whole-body energy expenditure and substrate utilisation. RESULTS: Transgenic mice showed a twofold increase in UCP3 protein levels specifically in glycolytic muscles. Mitochondrial respiration revealed an increase of uncoupling in glycolytic but not in oxidative muscles. Transgenic mice gained less weight than wild-type littermates due to lower adipose tissue accretion when fed a high-fat diet. Animals showed a sexual dimorphism in metabolic responses. Female transgenic mice were more glucose-sensitive than wild-type animals, while male transgenic mice with high body weights had impaired glucose and insulin tolerance. Measurements of RQs in mice fed chow and high-fat diets suggested an impairment of metabolic flexibility in transgenic male mice. CONCLUSIONS/INTERPRETATION: Our data show that physiological overproduction of UCP3 in glycolytic muscles results in mitochondrial uncoupling, resistance to high-fat diet-induced obesity and sex specificity regarding insulin sensitivity and whole-body substrate utilisation

Targeted Inactivation of Serum Response Factor in the Developing Heart Results in Myocardial Defects and Embryonic Lethality

Serum response factor (SRF) is at the confluence of multiple signaling pathways controlling the transcription of immediate-early response genes and muscle-specific genes. There are active SRF target sequences in more than 50 genes expressed in the three muscle lineages including normal and diseased hearts. However, the role of SRF in heart formation has not been addressed in vivo thus far due to the early requirement of SRF for mesoderm formation. We have generated a conditional mutant of SRF by using Cre-LoxP strategy that will be extremely useful to study the role of SRF in embryonic and postnatal cardiac functions, as well as in other tissues. This report shows that heart-specific deletion of SRF in the embryo by using a new βMHC-Cre transgenic mouse line results in lethal cardiac defects between embryonic day 10.5 (E10.5) and E13.5, as evidenced by abnormally thin myocardium, dilated cardiac chambers, poor trabeculation, and a disorganized interventricular septum. At E9.5, we found a marked reduction in the expression of essential regulators of heart development, including Nkx2.5, GATA4, myocardin, and the SRF target gene c-fos prior to overt maldevelopment. We conclude that SRF is crucial for cardiac differentiation and maturation, acting as a global regulator of multiple developmental genes