Pour une démocratie socio-environnementale : cadre pour une plate-forme participative « transition écologique »

Contribution publiée in Penser une démocratie alimentaire Volume II – Proposition Lascaux entre ressources naturelles et besoins fondamentaux, F. Collart Dutilleul et T. Bréger (dir), Inida, San José, 2014, pp. 87-111.International audienceL’anthropocène triomphant actuel, avec ses forçages environnementaux et sociaux, est à l’origine de l’accélération des dégradations des milieux de vie sur Terre et de l’accentuation des tensions sociales et géopolitiques. Passer à un anthropocène de gestion équitable, informé et sobre vis-à-vis de toutes les ressources et dans tous les secteurs d’activité (slow anthropocene), impose une analyse préalable sur l’ensemble des activités et des rapports humains. Cette transition dite « écologique », mais en réalité à la fois sociétale et écologique, est tout sauf un ajustement technique de secteurs dits prioritaires et technocratiques. Elle est avant tout culturelle, politique et philosophique au sens propre du terme. Elle est un horizon pour des trajectoires de développement humain, pour des constructions sociales et économiques, censées redéfinir socialement richesse, bien-être, travail etc. La dénomination « transition écologique » est largement véhiculée, mais ses bases conceptuelles ne sont pas entièrement acquises ni même élaborées. Dans ce contexte, les étudiants en première année de Master BioSciences à l’Ecole Normale Supérieure (ENS) de Lyon ont préparé une première étude analytique de ce changement radical et global de société pour mieux comprendre dans quelle société ils souhaitent vivre, en donnant du sens aux activités humaines présentes et à venir. Une trentaine de dossiers sur divers secteurs d’activités et acteurs de la société ont été produits et ont servis de support à cette synthèse. Plus largement, le but est de construire un socle conceptuel et une plate-forme de travail sur lesquels les questions de fond, mais aussi opérationnelles, peuvent être posées et étudiées en permanence. Cette démarche participative est ouverte à la collectivité sur le site http://institutmichelserres.ens-lyon.fr/

Computational Reverse-Engineering of a Spider-Venom Derived Peptide Active Against Plasmodium falciparum SUB1

merozoites and invasion into erythrocytes. As PfSUB1 has emerged as an interesting drug target, we explored the hypothesis that PcFK1 targeted PfSUB1 enzymatic activity. culture in a range compatible with our bioinformatics analysis. Using contact analysis and free energy decomposition we propose that residues A14 and Q15 are important in the interaction with PfSUB1.Our computational reverse engineering supported the hypothesis that PcFK1 targeted PfSUB1, and this was confirmed by experimental evidence showing that PcFK1 inhibits PfSUB1 enzymatic activity. This outlines the usefulness of advanced bioinformatics tools to predict the function of a protein structure. The structural features of PcFK1 represent an interesting protein scaffold for future protein engineering

Variations spatiales, temporelles et interindividuelles de survie et de phénologie de la reproduction chez la mésange bleue (Cyanistes caeruleus)

The study of life history traits and their covariations is critical to fully understand population demography and evolution. Among these traits, adult survival is central, as a component of fitness. Reproductive phenology is also a key element through its major consequences on fitness and through its sensitivity to environmental variations, particularly in the current context of climate change. The study of the relationship between these two traits is crucial in understanding the complex relationships between life history traits in a population. It is however surprisingly not often studied. This thesis aims to explore variations in survival in four populations of blue tit (Cyanistes caeruleus) in the Mediterranean region, and to examine the existence of links between survival and other demographic or environmental components of populations, including reproductive phenology. Using capture-mark-recapture models, we were able to estimate survival probabilities in the different populations. We showed that in one of these populations, the phenology of the population impacted adult survival at the population level (a decrease in the median laying date of the population causes a decrease in subsequent survival) as well as at the individual level (but in the opposite direction: the earliest individuals in the population are those who have the highest survival probabilities in the following year). These covariations are part of a complex relationship system that involves reproductive success (related to laying date), environment (which impacts laying date and reproductive success), and population density (which has negative effects on laying date, reproductive success and adult survival). In total, our work sheds new light on the processes related to adult survival and its spatial and temporal variations in the populations studied, as well as their links with environmental variations.L’étude des traits d’histoires de vie des organismes et de leurs covariations est extrêmement informative sur la démographie des populations ainsi que sur leur évolution. Parmi ces traits, la survie adulte est centrale en tant que composante de la valeur sélective. La phénologie de la reproduction est également un élément clef par ses conséquences majeures sur la valeur sélective et sa sensibilité aux variations environnementales, notamment dans le contexte actuel de changement climatique. L’étude du lien entre ces deux traits est déterminante dans la compréhension des relations complexes entre traits d’histoires de vie dans une population, mais il reste cependant peu étudié. Cette thèse vise à explorer les variations de survie dans quatre populations de mésanges bleues (Cyanistes caeruleus) en région méditerranéenne, et à examiner l’existence de lien entre celle-ci et d’autres composantes démographiques ou environnementales des populations, notamment la phénologie de la reproduction. Grâce à des modèles de type capture-marquage-recapture, nous avons pu estimer les taux de survie dans les différentes populations. Nous avons montré que dans l’une de ces populations, la phénologie de la population impactait la survie adulte au niveau populationnel (une diminution de la date de ponte médiane de la population est liée à une diminution de la survie) ainsi qu’au niveau individuel en sens contraire (les individus les plus précoces au sein de la population sont ceux qui ont la survie la plus élevée dans l’année qui suit). Ces covariations s’inscrivent dans un système de relations complexe qui fait intervenir le succès reproducteur (lié à la date de ponte), l’environnement (effet sur la date de ponte et sur le succès reproducteur), et la densité de population (effets sur la date de ponte, le succès reproducteur et sur la survie adulte). Au total, nos travaux éclairent d’un jour nouveau les processus liés à la survie adulte et ses variations spatio-temporelles dans les populations étudiées, ainsi que leurs liens avec les variations environnementales

Using miniaturized GPS archival tags to assess home range features of a small plunge-diving bird: the European Kingfisher (Alcedo atthis)

Abstract Background The European Kingfisher (Alcedo atthis) is a small plunge-diving bird, today considered a species of conservation concern in Europe given its rapid population decline observed across the continent. We implemented a pilot study aimed at providing first data allowing to: (1) assess home range features of the European Kingfisher for populations with unevenly distributed feeding habitats; (2) define conservation implications for habitats exploited by such populations; and (3) evaluate possibilities for developing GPS tracking schemes dedicated to home range studies for this species that could be possibly applied to other small plunge-diving birds. Methods In 2018 and 2019, we equipped 16 breeding European Kingfishers sampled within the marshes of the Gironde Estuary (France), with miniaturized and waterproof GPS archival tags deployed with leg-loop harnesses (total equipment mass = 1.4 g; average bird mass = 40.18 ± 1.12 g). Results On average, we collected 35.31 ± 6.66 locations usable for analyses, without a significant effect on bird body condition (n = 13 tags retrieved). Data analyses highlighted rather limited home ranges exploited by birds (average = 2.50 ± 0.55 ha), composed on average by 2.78 ± 0.40 location nuclei. Our results also underscore: (1) a rather important home range fragmentation index (0.36 ± 0.08); and (2) the use by birds of different types of small wetlands (wet ditches, small ponds or small waterholes), often exploited in addition to habitats encompassing nest locations. Conclusions Our study reveals interesting GPS tracking possibilities for small plunge-diving birds such as the European Kingfisher. For this species, today classified as vulnerable in Europe, our results underline the importance of developing conservation and ecological restoration policies for wetland networks that would integrate small wetlands particularly sensitive to global change

Identifying drivers of spatio-temporalvariation in survival in four blue tit populations

International audienceIn a context of rapid climate change, the influence of large-scale and local climate on population demography is increasingly scrutinized, yet studies are usually focused on one population. Demographic parameters, including survival, can vary significantly across populations of a given species, depending on global or local climatic fluctuations but also on many other population-specific parameters such as breeding density, habitat naturalness, predation or parasitism. Such ecological differences between populations could lead to different paces-of-life (POL), whereby populations where individuals display higher reproductive investment and bolder behaviours would have lower survival probabilities. We use here long-term (19 to 38 years) monitoring datasets from four Mediterranean populations of blue tits (Cyanistes caeruleus) to investigate the effects of sex, age class, large-scale and local climate temporal variation and population breeding density, on adult survival, using Capture-Mark-Recapture modelling. Environment heterogeneity in these four populations (two in evergreen and two in deciduous forests) has been linked to strong multi-trait phenotypic variation, suggesting blue tits in deciduous forests display faster POL compared to their conspecifics in evergreen habitats. The present results show heterogeneity in average survival probabilities across the four populations, with, as predicted, lower survival in the 'fast' blue tits occupying deciduous habitats. Interestingly, the year-to-year variation in survival probabilities was synchronous among populations. This suggests that regional environmental conditions could drive survival fluctuations across populations. However, breeding densities were not correlated across populations, and we found no evidence that adult survival is correlated with either large-scale or local, climate temporal variation in these four blue tit populations. Finally, two of the focal populations displayed a linear temporal decrease in adult survival over the study period, calling for further investigation to explain this decline. Overall, this multi-site study shows that blue tit parental survival from one spring to the next can vary substantially across years, in a synchronous way across populations, yet the climate indices we used are not correlated with the temporal variation. This calls for further investigations in other potential drivers such as resource (in particular insect) abundance, predation or parasitism

Bread Wheat TaSPO11‐1 exhibits evolutionary conserved function in meiotic recombination across distant plant species

International audienceThe manipulation of meiotic recombination in crops is essential to develop new plant varieties rapidly, helping to produce more cultivars in a sustainable manner. One option is to control the formation and repair of the meiosis-specific DNA double-strand breaks (DSBs) that initiate recombination between the homologous chromosomes and ultimately lead to crossovers. These DSBs are introduced by the evolutionarily conserved topoisomerase-like protein SPO11 and associated proteins. Here, we characterized the homoeologous copies of the SPO11-1 protein in hexaploid bread wheat (Triticum aestivum). The genome contains threeSPO11-1gene copies that exhibit 93-95% identity at the nucleotide level, and clearly the A and D copies originated from the diploid ancestorsTriticum urartuandAegilops tauschii, respectively. Furthermore, phylogenetic analysis of 105 plant genomes revealed a clear partitioning between monocots and dicots, with the seven main motifs being almost fully conserved, even between clades. The functional similarity of the proteins among monocots was confirmed through complementation analysis of theOryza sativa(rice)spo11-1mutant by the wheatTaSPO11-1-5Dcoding sequence. Also, remarkably, although the wheat and Arabidopsis SPO11-1 proteins share only 55% identity and the partner proteins also differ, theTaSPO11-1-5DcDNA significantly restored the fertility of the Arabidopsisspo11-1mutant, indicating a robust functional conservation of the SPO11-1 protein activity across distant plants. These successful heterologous complementation assays, using both Arabidopsis and rice hosts, are good surrogates to validate the functionality of candidate genes and cDNA, as well as variant constructs, when the transformation and mutant production in wheat is much longer and more tedious