Résumé
Cell identity relies on the cross-talk between genetics and epigenetics and their impact on gene expression. Oxidation of 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) is the first step of an active DNA demethylation process occurring mainly at enhancers and gene bodies and, as such, participates in processes governing cell identity in normal and pathological conditions. Although genetic alterations are well documented in multiple myeloma (MM), epigenetic alterations associated with this disease have not yet been thoroughly analyzed. To gain insight into the biology of MM, genome-wide 5hmC profiles were obtained and showed that regions enriched in this modified base overlap with MM enhancers and super enhancers and are close to highly expressed genes. Through the definition of a MM-specific 5hmC signature, we identified FAM72D as a poor prognostic gene located on 1q21, a region amplified in high risk myeloma. We further uncovered that FAM72D functions as part of the FOXM1 transcription factor network controlling cell proliferation and survival and we evidenced an increased sensitivity of cells expressing high levels of FOXM1 and FAM72 to epigenetic drugs targeting histone deacetylases and DNA methyltransferases.
Auteurs, date et publication :
Auteurs Fabrice Chatonnet , Amandine Pignarre , Aurélien A. Sérandour , Gersende Caron , Stéphane Avner , Nicolas Robert , Alboukadel Kassambara , Audrey Laurent , Maud Bizot , Xabier Agirre , Felipe Prosper , José I. Martin-Subero , Jérôme Moreaux , Thierry Fest , Gilles Salbert
Publication : Haematologica
Date : 2020
Volume : 105
Issue : 3
Pages : 774-783
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
The sustainability of agricultural, forested and other managed or
natural ecosystems is critical for the future of mankind. However, the
services provided by these ecosystems are under threat due to climate
change, loss of biodiversity, and land use changes. In order to face the
challenges of preserving or improving ecosystems services and securing
food supply we need to understand and forecast how ecosystems will
respond to current and future changes. To help answer those questions
Ecotrons facilities are born. Such infrastructures provide sets of
confinement units for the manipulation of environmental conditions and
real-time measurement of ecological processes under controlled and
reproduceable conditions, bridging the gap between the complexity of in
natura studies and the simplicity of laboratory experiments.The European
Ecotron of Montpellier (www.ecotron.cnrs.fr) is an experimental research
infrastructure for the study of the impact of climate change on
ecosystem functioning and biodiversity. This infrastructure offers,
through calls open to the international community, three experimental
platforms at different scales. The Macrocosms platform is composed of
twelve 40 m3 units, each able to host 2-12 t lysimeters, with a 2-5
m² canopy area and a soil depth of up to 2 m. The Mesocosms one has
eighteen 2-4 m3 units, each able to host lysimeters of 0.4-1 m depth and
0.4-1 m² area. The Microcosms platform consists of growth chambers
(1 m height, 1 m² area) in which smaller units (with photosynthetic
plants, soils, insects, etc.) can be installed. Each experimental unit
of each platform allows to confine terrestrial ecosystems. This way,
environmental parameters such as temperature (-10 to +50 °C),
relative humidity (20-80 %), precipitation (sprinkler or drip) and
atmospheric CO2 concentration (200-1000 ppm) are strictly and
continuously controlled and recorded. But the uniqueness of the European
Ecotron of Montpellier lies on its ability to also continuously measure,
in each unit, net gas exchange (evapotranspiration, CO2 / CH4 / N2O net
fluxes) that occur in between the ecosystem studied and the atmosphere,
as well as CO2, H2O, N2O and O2 isotopologues. Those tools are powerful
and remarkable to access additional information about processus involved
in ecosystem functioning.The aim of this presentation is to describe the
Macrocosms and the Mesocosms platforms through examples of international
projects recently run in these platforms.
Auteurs, date et publication :
Auteurs Joana Sauze , Jacques Roy , Clément Piel , Damien Landais , Emmanuel S. Gritti , Olivier Ravel , Hélène Lemoine , Abdelaziz Faez , Sébastien Devidal , Alexandru Milcu
Date : 2020
Volume : 22
Pages : 8650
Catégorie(s)
#CNRS #Ecotron de MontpellierRésumé
Biogeochemical Cycles: Ecological Drivers and Environmental Impact is a collection of the latest information on the techniques and methods currently used in this field, focusing on biological and/or ecological effects of biogeochemical elemental cycles including carbon, nitrogen, major and trace elements, chemical weathering on multiple scales of nanometers to watersheds, and advances in technology of studying these processes.Volume highlights include:- Remote sensing and modeling techniques used to quantify changes in the ecosystem/s productivity, and microscopic techniques to estimate the extent of weathering - Novel isotopic techniques to assess changes in trace elemental cycles as influenced by the changing climate, and plant-mediated effect of climate change on major elemental cycles - Impact of climate change and other anthropogenic influences in agricultural and extreme (frontier) environmentsBiogeochemical Cycles: Ecological Drivers and Environmental Impact is a valuable resource for students, researchers and professionals in the field of biogeosciences, hydrology, ecology, earth and planetary surface processes, volcanology, petrology, geochemistry, mineralogy, soil science, agricultural science, climate change and environmental science.
Auteurs, date et publication :
Auteurs Katerina Dontsova , Zsuzsanna Balogh-Brunstad , Gaël Le Roux
Date : 2020
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENSRésumé
The determinants of intraspecific stoichiometric variation remain difficult to elucidate due to their multiple origins (e.g. genetic vs. environmental) and potential interactive effects. We evaluated whether two size-selected lines of medaka (Oryzias latipes) with contrasted life-history strategies (small- and large-breeder lines with slow growth and early maturity vs. fast growth and late maturity) differed in their organismal stoichiometry (percentage and ratios of carbon [C], nitrogen [N] and phosphorus [P]) in a mesocosm experiment. We also tested how size-selection interacted with environmental conditions (i.e. two levels of fish density and light intensity), body condition and sex. Results showed that large-breeder fish were significantly N-enriched compared to small-breeders, while the two size-selected lines did not differ in body P composition. Size-selection interacted with density – high density only affected small-breeders leading to decreasing %C and C: N – and with sex – large-breeder females had higher %C and C:N values than large-breeder males. Finally, C:P and N:P ratios increased with body condition due to decreasing %P. Overall, our results show that the ecological consequences of size-selective mortality extend to organismal stoichiometry and may, from there, change nutrient cycling and ecosystem functioning.
Auteurs, date et publication :
Auteurs Charlotte Evangelista , Beatriz Diaz Pauli , Leif Asbjørn Vøllestad , Eric Edeline
Publication : Science of The Total Environment
Date : 2020
Volume : 724
Pages : 138193
Catégorie(s)
#ANR-Citation #CNRS #Ecotron IleDeFrance #ENSRésumé
Most models simulating snow albedo assume a flat and smooth surface, neglecting surface roughness. However, the presence of macroscopic roughness leads to a systematic decrease in albedo due to two effects: (1) photons are trapped in concavities (multiple reflection effect) and (2) when the sun is low, the roughness sides facing the sun experience an overall decrease in the local incidence angle relative to a smooth surface, promoting higher absorption, whilst the other sides have weak contributions because of the increased incidence angle or because they are shadowed (called the effective-angle effect here). This paper aims to quantify the impact of surface roughness on albedo and to assess the respective role of these two effects, with (1) observations over varying amounts of surface roughness and (2) simulations using the new rough surface ray-tracing (RSRT) model, based on a Monte Carlo method for photon transport calculation. The observations include spectral albedo (400-1050 nm) over manually created roughness surfaces with multiple geometrical characteristics. Measurements highlight that even a low fraction of surface roughness features (7% of the surface) causes an albedo decrease of 0.02 at 1000 nm when the solar zenith angle (theta(s)) is larger than 50 degrees. For higher fractions (13 %, 27% and 63 %), and when the roughness orientation is perpendicular to the sun, the decrease is of 0.03-0.04 at 700 nm and of 0.06-0.10 at 1000 nm. The impact is 20% lower when roughness orientation is parallel to the sun. The observations are subsequently compared to RSRT simulations. Accounting for surface roughness improves the model observation agreement by a factor of 2 at 700 and 1000 nm (errors of 0.03 and 0.04, respectively) compared to simulations considering a flat smooth surface. The model is used to explore the albedo sensitivity to surface roughness with varying snow properties and illumination conditions. Both multiple reflections and the effective-angle effect have a greater impact with low specific surface area (SSA; < 10m(2) kg(-1)). The effective-angle effect also increases rapidly with theta(s) at large theta(s). This latter effect is larger when the overall slope of the surface is facing away from the sun and has a roughness orientation perpendicular to the sun. For a snowpack where artificial surface roughness features were created, we showed that a broadband albedo decrease of 0.05 may cause an increase in the net shortwave radiation of 80% (from 15 to 27Wm(-2)). This paper highlights the necessity of considering surface roughness in the estimation of the surface energy budget and opens the way for considering natural rough surfaces in snow modelling.
Auteurs, date et publication :
Auteurs Fanny Larue , Ghislain Picard , Laurent Arnaud , Ines Ollivier , Clement Delcourt , Maxim Lamare , Francois Tuzet , Jesus Revuelto , Marie Dumont
Publication : CRYOSPHERE
Date : 2020
Volume : 14
Issue : 5
Pages : 1651-1672
Catégorie(s)
#ANR-Citation #CNRS #Lautaret #UGARésumé
Urban habitat characteristics create environmental filtering of pollinator communities. They also impact pollinating insect phenology through the presence of an urban heat island and the year-round availability of floral resources provided by ornamental plants. Here, we monitored the phenology and composition of pollinating insect communities visiting replicates of an experimental plant assemblage comprising two species, with contrasting floral traits:Sinapis albaandLotus corniculatus, whose flowering periods were artificially extended. Plant assemblage replicates were set up over two consecutive years in two different habitats: rural and densely urbanized, within the same biogeographical region (Ile-de-France region, France). The phenology of pollination activity, recorded from the beginning (early March) to the end (early November) of the season, differed between these two habitats. Several pollinator morphogroups (small wild bees, bumblebees, honeybees) were significantly more active on our plant sets in the urban habitat compared to the rural one, especially in early spring and autumn. This resulted in different overall reproductive success of the plant assemblage between the two habitats. Over the course of the season, reproductive success ofS. albawas always significantly higher in the urban habitat, while reproductive success ofL. corniculatuswas significantly higher in the urban habitat only during early flowering. These findings suggest different phenological adaptations to the urban habitat for different groups of pollinators. Overall, results indicate that the broadened activity period of pollinating insects recorded in the urban environment could enhance the pollination function and the reproductive success of plant communities in cities.
Auteurs, date et publication :
Auteurs Vincent Zaninotto , Xavier Raynaud , Emmanuel Gendreau , Yvan Kraepiel , Eric Motard , Olivier Babiar , Amandine Hansart , Cecile Hignard , Isabelle Dajoz
Publication : ECOLOGY AND EVOLUTION
Date : 2020
Volume : 10
Issue : 20
Pages : 11607-11621
Catégorie(s)
#ANR-Citation #CEREEP #CNRS #ENSRésumé
Asexual reproduction has often been regarded as an evolutionary dead end, but asexual lineages (most notably those that are apomictic) are present in several angiosperm families and often comprise a large number of taxa, both widespread and endemic. Investigating correlations between genetic, environmental and taxonomic factors and the incidence of apomixis has represented a challenge for many years, with previous analyses frequently omitting one or more of these variables. Here, flow cytometric seed screening, cytological data and ecological variables have been integrated in a phylogenetic framework to create a comprehensive dataset for 229 of Asteraceae from the European Alps. Data were analysed using phylogenetically informed generalized linear mixed models (pMCMCglmm) where elevation, ploidy and phenology were assessed for their potential correlation with asexual reproduction and apomixis type. Although apomixis is not dominant among the species studied, our results confirm that an odd ploidy (e.g. 3x) and, to a lesser extent, an even polyploid level (i.e. 4x) significantly increase its probability, most probably due to chromosome misalignments during meiosis. The distribution of apomictic species does not correlate with elevation, and there is a weak correlation between early flowering initiation and aposporous apomixis. Although current and future changes in climate may severely impact the survival of the flora of the European Alps, asexual reproduction and polyploidization may prove to be, at least temporarily, lifelines for the survival of a species under the novel climatic conditions. Therefore, uncovering how apomicts and polyploids evolve and persist will be essential for understanding the ecology of the European Alps and hence informing future conservation strategies.
Auteurs, date et publication :
Auteurs Luca Pegoraro , Ellen C Baker , David Aeschimann , Manica Balant , Rolland Douzet , Teresa Garnatje , Maïté S Guignard , Ilia J Leitch , Andrew R Leitch , Luis Palazzesi , Jean-Paul Theurillat , Oriane Hidalgo , Jaume Pellicer
Publication : Botanical Journal of the Linnean Society
Date : 2020
Volume : 194
Issue : 4
Pages : 410-422
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Egg size has a crucial impact on the reproductive success of a mother and the performance of her offspring. It is therefore reasonable to employ egg size as a proxy for egg content when studying variation in offspring performance. Here, we tested species differences in allometries of several egg content parameters with egg area. We measured individual eggs in five species of annual killifish (Cyprinodontiformes), a group of fish where egg banks permit population survival over dry season. Apart from comparing allometric scaling exponents, amounts and compositions of egg components across the different species, we assessed the explanatory power of egg area for egg wet and dry weight and for hatchling size. We found notable species-specific allometries between egg area and the other egg parameters (egg dry weight and water content, elemental composition and triglyceride content). Across species, egg area predicted egg wet weight with highest power. Within species, coefficients of determination were largest in A. elongatus, a large piscivorous species with large eggs. Our study shows that systematically using egg area as a proxy of egg content between different species can ignore relevant speciesspecific differences and mask within-species variability in egg content.
Auteurs, date et publication :
Auteurs Milan Vrtilek , Tom J. M. Van Dooren , Megane Beaudard
Publication : COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY
Date : 2020
Volume : 249
Catégorie(s)
#ANR-Citation #CEREEP #CNRS #ENSRésumé
A major challenge remains to understand the relative contributions of history, dispersal, and environmental filtering to the assembly of hyperdiverse communities across spatial scales. Here, we examine the extent to which biogeographical history and habitat specialization have generated turnover among and within lineages of Amazonian trees across broad geographic and environmental gradients. We replicated standardized tree inventories in 102 0.1-ha plots located in two distant regions—the western Amazon and the eastern Guiana shield. Within each region, we used a nested design to replicate plots on contrasted habitats: white-sand, terra firme, and seasonally flooded forests. Our plot network encompassed 26,386 trees that together represented 2,745 distinct taxa, which we standardized across all plots and regions. We combined taxonomic and phylogenetic data with detailed soil measurements and climatic data to: (1) test whether patterns of taxonomic and phylogenetic composition are consistent with recent or historical processes, (2) disentangle the relative effects of habitat, environment, and geographic distance on taxonomic and phylogenetic turnover among plots, and (3) contrast the proportion of habitat specialists among species from each region. We found substantial species turnover between Peru and French Guiana, with only 8.8% of species shared across regions; genus composition remained differentiated across habitats and regions, whereas turnover at higher taxonomic levels (family, order) was much lower. Species turnover across plots was explained primarily by regions, but also substantially by habitat differences and to a lesser extent by spatial distance within regions. Conversely, the composition of higher taxonomic levels was better explained by habitats (especially comparing white-sand forests to other habitats) than spatial distance. White-sand forests harbored most of the habitat specialists in both regions, with stronger habitat specialization in Peru than in French Guiana. Our results suggest that recent diversification events have resulted in extremely high turnover in species and genus composition with relatively little change in the composition of higher lineages. Our results also emphasize the contributions of rare habitats, such as white-sand forests, to the extraordinary diversity of the Amazon and underline their importance as conservation priorities.
Auteurs, date et publication :
Auteurs Christopher Baraloto , Jason Vleminckx , Julien Engel , Pascal Petronelli , Nállarett Dávila , Marcos RÍos , Elvis Harry Valderrama Sandoval , Italo Mesones , Juan Ernesto Guevara Andino , Claire Fortunel , Elodie Allie , C. E. Timothy Paine , Aurélie Dourdain , Jean-Yves Goret , Oscar J. Valverde-Barrantes , Freddie Draper , Paul V. A. Fine
Publication : Ecological Monographs
Date : 2025
Volume : 91
Issue : 4
Pages : e01473
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Primary Biogenic Organic Aerosols (PBOA) were recently shown to be produced by only a few types of microorganisms, emitted by the surrounding vegetation in the case of a regionally homogeneous field site. This study presents the first comprehensive description of the structure and main sources of airborne microbial communities associated with temporal trends in Sugar Compounds (SC) concentrations of PM10 in 3 sites under a climatic gradient in France. By combining sugar chemistry and DNA Metabarcoding approaches, we intended to identify PM10-associated microbial communities and their main sources at three sampling-sites in France, under different climates, during the summer of 2018. This study accounted also for the interannual variability in summer airborne microbial community structure (bacteria and fungi only) associated with PM10-SC concentrations during a 2 consecutive years' survey at one site. Our results showed that temporal changes in PM10-SC in the three sites are associated with the abundance of only a few specific taxa of airborne fungi and bacterial. These taxa differ significantly between the 3 climatic regions studied. The microbial communities structure associated with SC concentrations of PM10 during a consecutive 2-year study remained stable in the rural area. Atmospheric concentration levels of PM10-SC species varied significantly between the 3 study sites, but with no clear difference according to site typology (rural vs. urban), suggesting that SC emissions are related to regional rather than local climatic characteristics. The overall microbial beta diversity in PM10 samples is significantly different from that of the main vegetation around the urban sites studied. This indicates that the airborne microorganisms at these urban sites are not solely from the immediate surrounding vegetation, which contrasts with observations at the scale of a regionally homogeneous rural site in 2017. These results improve our understanding of the spatial behavior of tracers of PBOA emission sources, which need to be better characterized to further implement this important mass fraction of Organic Matter (OM) in Chemical Transport models (CTM).
Auteurs, date et publication :
Auteurs Abdoulaye Samaké , Jean M F Martins , Aurélie Bonin , Gaëlle Uzu , Pierre Taberlet , Sébastien Conil , Olivier Favez , Alexandre Thomasson , Benjamin Chazeau , Nicolas Marchand , Jean-Luc Jaffrezo
Publication : Frontiers in Microbiology
Date : 2025
Volume : 11
Pages : 576750