Résumé
Earthworms in interaction with soil microorganisms play a key role in litter decomposition. Moreover, as soil engineers, earthworms modify microbial communities and their enzymatic activities. Most studies focusing on earthworms and soil enzymatic activities compare distinct ecological categories of earthworms whereas their contributions and interactions within a given ecological category remain largely unknown. In this context, the aims of the present study were to determine and compare the contribution of (1) three strict-anecic earthworm species, (2) three epi-anecic earthworm species and (3) the pairwise interactions between these different species on Lolium perenne leaf litter decomposition and soil microbial activity. After 30 days of incubation, the surface litter mass loss and five soil enzymatic activities (FDAse, β-D-glucosidase, cellobiohydrolase, leucine amino-peptidase and acid phosphatase) were measured in both earthworm burrows and middens. In mono-specific assemblages, leaf litter mass loss and enzymatic activities were significantly higher in the presence of epi-anecic compared to strict-anecic species, whatever the species identity. These differences were higher for the β-D-glucosidase, leucine amino-peptidase and FDAse (+78%, +57% and +34%, respectively). Earthworm species interactions at both intra- and inter-ecological sub-categories did not enhance either leaf litter mass loss or enzymatic activities. Interestingly, FDAse activity was higher in earthworm burrows whereas acid phosphatase activity was higher in earthworm middens. These results indicate that the two anecic ecological sub-categories have different impacts on soil functioning and each of them regroups earthworm species with similar behaviour. This functional distinction highlights the key role of epi-anecic earthworms in fresh surface litter burial and decomposition, featuring their importance on nutrient cycling in soil and for microbial activities stimulation through resource availability.
Auteurs, date et publication :
Auteurs Kevin Hoeffner , Mathieu Santonja , Daniel Cluzeau , Cécile Monard
Publication : Soil Biology and Biochemistry
Date : 2019
Volume : 132
Pages : 93-100
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Type III epithelial–mesenchymal transition (EMT) has been previously associated with increased cell migration, invasion, metastasis, and therefore cancer aggressiveness. This reversible process is associated with an important gene expression reprogramming mainly due to epigenetic plasticity. Nevertheless, most of the studies describing the central role of epigenetic modifications during EMT were performed in a single-cell model and using only one mode of EMT induction. In our study, we studied the overall modulations of gene expression and epigenetic modifications in four different EMT-induced cell models issued from different tissues and using different inducers of EMT. Pangenomic analysis (transcriptome and ChIP–sequencing) validated our hypothesis that gene expression reprogramming during EMT is largely regulated by epigenetic modifications of a wide range of genes. Indeed, our results confirmed that each EMT model is unique and can be associated with a specific transcriptome profile and epigenetic program. However, we could select some genes or pathways that are similarly regulated in the different models and that could therefore be used as a common signature of all EMT models and become new biomarkers of the EMT phenotype. As an example, we can cite the regulation of gene-coding proteins involved in the degradation of the extracellular matrix (ECM), which are highly induced in all EMT models. Based on our investigations and results, we identified ADAM19 as a new biomarker of in vitro and in vivo EMT and we validated this biological new marker in a cohort of non-small lung carcinomas.
Auteurs, date et publication :
Auteurs Paul Peixoto , Amandine Etcheverry , Marc Aubry , Anaïs Missey , Camille Lachat , Jérôme Perrard , Elodie Hendrick , Régis Delage-Mourroux , Jean Mosser , Christophe Borg , Jean-Paul Feugeas , Michaël Herfs , Michaël Boyer-Guittaut , Eric Hervouet
Publication : Cell Death & Disease
Date : 2019
Volume : 10
Issue : 3
Pages : 1-17
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are approved for second-line treatment of EGFR wild-type (EGFR-wt) nonsmall cell lung cancer (NSCLC). However, results from randomised trials performed to compare EGFR-TKIs with chemotherapy in this population did not show any survival benefit. In the era of immunotherapy, many drugs are approved for second-line treatment of EGFR-wt NSCLC and there is a need to reassess the role of EGFR-TKIs in this setting.The Biomarkers France study is a large nationwide cohort of NSCLC patients tested for EGFR mutations. We used this database to collect clinical, biological, treatment and outcome data on EGFR-wt patients who received second-line treatment with either EGFR-TKIs or chemotherapy.Among 1278 patients, 868 received chemotherapy and 410 received an EGFR-TKI. Median overall survival and progression-free survival were longer with chemotherapy than with an EGFR-TKI. Overall survival was 8.38 versus 4.99 months, respectively (hazard ratio 0.70, 95% CI 0.59-0.83; p<0.0001) and progression-free survival was 4.30 versus 2.83 months, respectively (hazard ratio 0.66, 95% CI 0.57-0.77; p<0.0001).This study is helpful to guide a multiline treatment strategy for EGFR-wt NSCLC patients. Immunotherapy is approved for second-line treatment. For third-line treatment, chemotherapy results in longer overall survival and progression-free survival, and should be preferred to EGFR-TKIs.
Auteurs, date et publication :
Auteurs Pascale Tomasini , Solenn Brosseau , Julien Mazières , Jean-Philippe Merlio , Michèle Beau-Faller , Jean Mosser , Marie Wislez , L'Houcine Ouafik , Benjamin Besse , Isabelle Rouquette , Didier Debieuvre , Fabienne Escande , Virginie Westeel , Clarisse Audigier-Valette , Pascale Missy , Alexandra Langlais , Frank Morin , Denis Moro-Sibilot , Gérard Zalcman , Fabrice Barlesi
Publication : The European Respiratory Journal
Date : 2017
Volume : 50
Issue : 2
Pages : 1700514
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Fungal communities in the root endosphere are heterogeneous at fine scale. The passenger hypothesis assumes that this heterogeneity is driven by host plant distribution. Plant composition and host plant configuration should then influence root fungal assemblages. We used a large-scale experimental design of 25 mixtures of grassland plants. We sampled Brachypodium pinnatum in each mesocosm, and used amplicon mass-sequencing to analyze the endospheric mycobiota. We used plant distribution maps to assess plant species richness and evenness (heterogeneity of composition), and patch size and the degree of isolation of B. pinnatum (heterogeneity of configuration) on fungal community assembly. The Glomeromycotina community in B. pinnatum roots was not related to either floristic heterogeneity or productivity. For Ascomycota, the composition of operational taxonomic units (OTUs) was driven by plant evenness while OTU richness decreased with plant richness. For Basidiomycota, richness increased with host plant aggregation and connectivity. Plant productivity influenced Ascomycota, inducing a shift in OTU composition and decreasing evenness. Plant heterogeneity modified root mycobiota, with potential direct (i.e. host preference) and indirect (i.e. adaptations to abiotic conditions driven by plant occurrence over time) effects. Plant communities can be envisioned as microlandscapes consisting of a variety of fungal niches.
Auteurs, date et publication :
Auteurs Cendrine Mony , Philomène Brunellière , Nathan Vannier , Anne-Kristel Bittebiere , Philippe Vandenkoornhuyse
Publication : New Phytologist
Date : 2025
Volume : 225
Issue : 4
Pages : 1777-1787
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
BACKGROUND: Within the root endosphere, fungi are known to be important for plant nutrition and resistance to stresses. However, description and understanding of the rules governing community assembly in the fungal fraction of the plant microbiome remains scarce.
METHODS: We used an innovative DNA- and RNA-based analysis of co-extracted nucleic acids to reveal the complexity of the fungal community colonizing the roots of an Agrostis stolonifera population. The normalized RNA/DNA ratio, designated the 'mean expression ratio', was used as a functional trait proxy. The link between this trait and phylogenetic relatedness was measured using the Blomberg's K statistic.
RESULTS: Fungal communities were highly diverse. Only ∼1.5% of the 635 OTUs detected were shared by all individuals, however these accounted for 33% of the sequence number. The endophytic fungal communities in plant roots exhibit phylogenetic clustering that can be explained by a plant host effect acting as environmental filter. The 'mean expression ratio' displayed significant but divergent phylogenetic signals between fungal phyla.
DISCUSSION: These results suggest that environmental filtering by the host plant favours the co-existence of related and similar OTUs within the Basidiomycota community assembly, whereas the Ascomycota and Glomeromycota communities seem to be impacted by competitive interactions which promote the co-existence of phylogenetically related but ecologically dissimilar OTUs.
Auteurs, date et publication :
Auteurs Amandine Lê Van , Achim Quaiser , Marie Duhamel , Sophie Michon-Coudouel , Alexis Dufresne , Philippe Vandenkoornhuyse
Publication : PeerJ
Date : 2025
Volume : 5
Pages : e3454
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Ecological corridors promote species coexistence in fragmented habitats where dispersal limits species fluxes. The corridor concept was developed and investigated with macroorganisms in mind while microorganisms, the invisible majority of biodiversity, were disregarded. We analyzed the effect of corridors on the dynamics of endospheric fungal assemblages associated with plant roots at the scale of one meter over two years (i.e. at five time points) by combining an experimental corridor-mesocosm with high-throughput amplicon sequencing. We show that the plant root endospheric mycobiota was sensitive to corridor effects when the corridors were set up at a small spatial scale. The endospheric mycobiota of connected plants had higher species richness, lower beta-diversity, and more deterministic assembly than the mycobiota of isolated plants. These effects became more pronounced with the development of host plants. Biotic corridors composed of host plants may thus play a key role in the spatial dynamics of microbial communities and may influence microbial diversity and related ecological functions.
Auteurs, date et publication :
Auteurs Jie Hu , Philippe Vandenkoornhuyse , Fadwa Khalfallah , Romain Causse-Védrines , Cendrine Mony
Publication : New Phytologist
Date : 2025
Volume : n/a
Issue : n/a
Catégorie(s)
#CNRS #EcoGenO #Université de RennesAuteurs, date et publication :
Auteurs Xu Pan , Mathieu Santonja , Pierre Emmanuel Courty , Olaf Butensch n , Matty Berg , Phil Murray , Benjamin Yguel , Daphn e Brul , Andreas Prinzing
Publication : Authorea
Date : 2020
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Abstract Proteostasis imbalance is emerging as a major hallmark of cancer, driving tumor aggressiveness. Evidence suggests that the endoplasmic reticulum (ER), a major site for protein folding and quality control, plays a critical role in cancer development. This concept is valid in glioblastoma multiform (GBM), the most lethal primary brain cancer with no effective treatment. We previously demonstrated that the ER stress sensor IRE1α (referred to as IRE1) contributes to GBM progression, through XBP1 mRNA splicing and regulated IRE1-dependent decay (RIDD) of RNA. Here, we first demonstrated IRE1 signaling significance to human GBM and defined specific IRE1-dependent gene expression signatures that were confronted to human GBM transcriptomes. This approach allowed us to demonstrate the antagonistic roles of XBP1 mRNA splicing and RIDD on tumor outcomes, mainly through selective remodeling of the tumor stroma. This study provides the first demonstration of a dual role of IRE1 downstream signaling in cancer and opens a new therapeutic window to abrogate tumor progression.
Auteurs, date et publication :
Auteurs Stéphanie Lhomond , Tony Avril , Nicolas Dejeans , Konstantinos Voutetakis , Dimitrios Doultsinos , Mari McMahon , Raphaël Pineau , Joanna Obacz , Olga Papadodima , Florence Jouan , Heloise Bourien , Marianthi Logotheti , Gwénaële Jégou , Néstor Pallares-Lupon , Kathleen Schmit , Pierre-Jean Le Reste , Amandine Etcheverry , Jean Mosser , Kim Barroso , Elodie Vauléon
Publication : EMBO Molecular Medicine
Date : 2018
Volume : 10
Issue : 3
Pages : e7929
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Highly differentiated mature spermatozoa carry not only genetic but also epigenetic information that is to be transmitted to the embryo. DNA methylation is one epigenetic actor associated with sperm nucleus compaction, gene silencing, and prepatterning of embryonic gene expression. Therefore, the stability of this mark toward reproductive biotechnologies is a major issue in animal production. The present work explored the impact of hormonal induction of spermiation and sperm cryopreservation in two cyprinids, the goldfish (Carassius auratus) and the zebrafish (Danio rerio), using LUminometric Methylation Assay (LUMA). We showed that while goldfish hormonal treatment did increase sperm production, it did not alter global DNA methylation of spermatozoa. Different sperm samples repeatedly collected from the same males for 2 months also showed the same global DNA methylation level. Similarly, global DNA methylation was not affected after cryopreservation of goldfish spermatozoa with methanol, whereas less efficient cryoprotectants (dimethylsulfoxide and 1,2-propanediol) decreased DNA methylation. In contrast, cryopreservation of zebrafish spermatozoa with methanol induced a slight, but significant, increase in global DNA methylation. In the less compact nuclei, that is, goldfish fin somatic cells, cryopreservation did not change global DNA methylation regardless of the choice of cryoprotectant. To conclude, global DNA methylation is a robust parameter with respect to biotechnologies such as hormonal induction of spermiation and sperm cryopreservation, but it can be altered when the best sperm manipulation conditions are not met.
Auteurs, date et publication :
Auteurs Alexandra Depincé , Anne Gabory , Katarzyna Dziewulska , Pierre-Yves Le Bail , Hélène Jammes , Catherine Labbé
Publication : Molecular Reproduction and Development
Date : 2025
Volume : 87
Issue : 1
Pages : 124-134
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Modern plant breeding and agrosystems artificialization could have altered plants’ ability to filter and recruit beneficial microorganisms in its microbiota. Thus, compared to modern cultivars, we hypothesized that root-endosphere microbiota in modern wheat cultivars are less resistant to colonization by fungi and bacteria and thus more susceptible to also recruit more pathogens. We used an in-field experimental design including six wheat varieties (three ancient vs. three modern) grown in monoculture and in mixture (three replicates each). Endospheric microbiota of wheat roots were analyzed on four individuals sampled randomly in each plot. Composition-based clustering of sequences was then characterized from amplicon mass-sequencing. We show that the bacterial and fungal microbiota composition in wheat roots differed between ancient and modern wheat cultivar categories. However, the responses observed varied with the group considered. Modern cultivars harbored higher richness of bacterial and fungal pathogens than ancient cultivars. Both cultivar types displayed specific indicator species. A synergistic effect was identified in mixtures of modern cultivars with a higher root endospheric mycobiota richness than expected from a null model. The present study shows the effect of plant breeding on the microbiota associated plant roots. The results call for making a diagnosis of the cultivar's endospheric-microbiota composition. These new results also suggest the importance of a holobiont-vision while considering plant selection in crops and call for better integration of symbiosis in the development of next-generation agricultural practices.
Auteurs, date et publication :
Auteurs Solène Mauger , Claire Ricono , Cendrine Mony , Vèronique Chable , Estelle Serpolay , Marine Biget , Philippe Vandenkoornhuyse
Publication : Plant-Environment Interactions
Date : 2025
Volume : 2
Issue : 5
Pages : 235-248