Auteurs, date et publication :
Auteurs PIG MALE , Anne Loiseau , Arnaud Estoup , Angelique Quilichini , Jerome Orivel
Publication : European Journal of Entomology
Date : 2025
Volume : 107
Issue : 4
Pages : 673-675
Catégorie(s)
#CNRS #FORET NouraguesRésumé
The opportunistic pathogen Pseudomonas aeruginosa is one of the “critical priority pathogens” due to its multidrug resistance to a wide range of antibiotics. Its ability to invade and damage host tissues is due to the use of quorum sensing (QS) to collectively produce a plethora of virulence factors. Inhibition of QS is an attractive strategy for new antimicrobial agents because it disrupts the initial events of infection without killing the pathogen. Highly diverse microorganisms as endophytes represent an under-explored source of bioactive natural products, offering opportunities for the discovery of novel QS inhibitors (QSI). In the present work, the objective was to explore selective QSIs within a unique collection of fungal endophytes isolated from the tropical palm Astrocaryum sciophilum. The fungi were cultured, extracted, and screened for their antibacterial and specific anti-QS activities against P. aeruginosa. The endophytic strain Lasiodiplodia venezuelensis was prioritized for scaled-up fractionation for its selective activity, leading to the isolation of eight compounds in a single step. Among them, two pyran-derivatives were found to be responsible for the QSI activity, with an effect on some QS-regulated virulence factors. Additional non-targeted metabolomic studies on P. aeruginosa documented their effects on the production of various virulence-related metabolites.
Auteurs, date et publication :
Auteurs Léonie Pellissier , Sara Leoni , Laurence Marcourt , Emerson Ferreira Queiroz , Nicole Lecoultre , Luis-Manuel Quiros-Guerrero , Morgane Barthélémy , Véronique Eparvier , Jérôme Chave , Didier Stien , Katia Gindro , Karl Perron , Jean-Luc Wolfender
Publication : Microorganisms
Date : 2021
Volume : 9
Issue : 9
Pages : 1807
Catégorie(s)
#CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Eva Ringler , Andrius Pasukonis , Walter Hodl , Max Ringler
Publication : The Herpetological Journal
Date : 2025
Volume : 23
Issue : 3
Pages : 175-178
Catégorie(s)
#⛔ No DOI found #CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Eva Ringler , Bibiana Rojas , Max Ringler , Walter Hodl
Publication : The Herpetological Journal
Date : 2025
Volume : 22
Issue : 4
Pages : 263-265
Catégorie(s)
#⛔ No DOI found #CNRS #FORET NouraguesRésumé
Concern about the functional consequences of unprecedented loss in biodiversity has prompted biodiversity–ecosystem functioning (BEF) research to become one of the most active fields of ecological research in the past 25 years. Hundreds of experiments have manipulated biodiversity as an independent variable and found compelling support that the functioning of ecosystems increases with the diversity of their ecological communities. This research has also identified some of the mechanisms underlying BEF relationships, some context-dependencies of the strength of relationships, as well as implications for various ecosystem services that humankind depends upon. In this chapter, we argue that a multitrophic perspective of biotic interactions in random and non-random biodiversity change scenarios is key to advance future BEF research and to address some of its most important remaining challenges. We discuss that the study and the quantification of multitrophic interactions in space and time facilitates scaling up from small-scale biodiversity manipulations and ecosystem function assessments to management-relevant spatial scales across ecosystem boundaries. We specifically consider multitrophic conceptual frameworks to understand and predict the context-dependency of BEF relationships. Moreover, we highlight the importance of the eco-evolutionary underpinnings of multitrophic BEF relationships. We outline that FAIR data (meeting the standards of findability, accessibility, interoperability, and reusability) and reproducible processing will be key to advance this field of research by making it more integrative. Finally, we show how these BEF insights may be implemented for ecosystem management, society, and policy. Given that human well-being critically depends on the multiple services provided by diverse, multitrophic communities, integrating the approaches of evolutionary ecology, community ecology, and ecosystem ecology in future BEF research will be key to refine conservation targets and develop sustainable management strategies.
Auteurs, date et publication :
Auteurs Nico Eisenhauer , Holger Schielzeth , Andrew D. Barnes , Kathryn E. Barry , Aletta Bonn , Ulrich Brose , Helge Bruelheide , Nina Buchmann , François Buscot , Anne Ebeling , Olga Ferlian , Grégoire T. Freschet , Darren P. Giling , Stephan Hättenschwiler , Helmut Hillebrand , Jes Hines , Forest Isbell , Eva Koller-France , Birgitta König-Ries , Hans de Kroon
Date : 2019
Volume : 61
Pages : 1-54
Catégorie(s)
#CNRS #Ecotron de MontpellierAuteurs, date et publication :
Auteurs Bruno Locatelli , Sandra Lavorel , Sean Sloan , Ulrike Tappeiner , Davide Geneletti
Publication : Frontiers in Ecology and the Environment
Date : 2025
Volume : 15
Issue : 3
Pages : 150-159
Catégorie(s)
#CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Nicolas Guibert , Fabrice Barlesi , Renaud Descourt , Hervé Lena , Benjamin Besse , Michèle Beau-Faller , Jean Mosser , Eric Pichon , Jean-Philippe Merlio , l'Houcine Ouafik , François Guichard , Bénédicte Mastroianni , Lionel Moreau , Annie Wdowik , Jean-Christophe Sabourin , Antoinette Lemoine , Pascale Missy , Alexandra Langlais , Denis Moro-Sibilot , Julien Mazières
Publication : Journal of Thoracic Oncology
Date : 2017
Volume : 12
Issue : 6
Pages : 963
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
The repetitive content of the plant genome (repeatome) often represents its largest fraction and is frequently correlated with its size. Transposable elements (TEs), the main component of the repeatome, are an important driver in the genome diversification due to their fast-evolving nature. Hybridization and polyploidization events are hypothesized to induce massive bursts of TEs resulting, among other effects, in an increase of copy number and genome size. Little is known about the repeatome dynamics following hybridization and polyploidization in plants that reproduce by apomixis (asexual reproduction via seeds). To address this, we analyzed the repeatomes of two diploid parental species, Hieracium intybaceum and H. prenanthoides (sexual), their diploid F1 synthetic and their natural triploid hybrids (H. pallidiflorum and H. picroides, apomictic). Using low-coverage next-generation sequencing (NGS) and a graph-based clustering approach, we detected high overall similarity across all major repeatome categories between the parental species, despite their large phylogenetic distance. Medium and highly abundant repetitive elements comprise ∼70% of Hieracium genomes; most prevalent were Ty3/Gypsy chromovirus Tekay and Ty1/Copia Maximus-SIRE elements. No TE bursts were detected, neither in synthetic nor in natural hybrids, as TE abundance generally followed theoretical expectations based on parental genome dosage. Slight over- and under-representation of TE cluster abundances reflected individual differences in genome size. However, in comparative analyses, apomicts displayed an overabundance of pararetrovirus clusters not observed in synthetic hybrids. Substantial deviations were detected in rDNAs and satellite repeats, but these patterns were sample specific. rDNA and satellite repeats (three of them were newly developed as cytogenetic markers) were localized on chromosomes by fluorescence in situ hybridization (FISH). In a few cases, low-abundant repeats (5S rDNA and certain satellites) showed some discrepancy between NGS data and FISH results, which is due partly to the bias of low-coverage sequencing and partly to low amounts of the satellite repeats or their sequence divergence. Overall, satellite DNA (including rDNA) was markedly affected by hybridization, but independent of the ploidy or reproductive mode of the progeny, whereas bursts of TEs did not play an important role in the evolutionary history of Hieracium.
Auteurs, date et publication :
Auteurs Danijela Zagorski , Matthias Hartmann , Yann J. K. Bertrand , Ladislava Paštová , Renata Slavíková , Jiřina Josefiová , Judith Fehrer
Publication : Frontiers in Plant Science
Date : 2020
Volume : 11
Catégorie(s)
#CNRS #Lautaret #UGARésumé
In eukaryotes, the spatial and temporal organization of genome duplication gives rise to distinctive profiles of replication origin usage along the chromosomes. While it has become increasingly clear that these programs are important for cellular physiology, the mechanisms by which they are determined and modulated remain elusive. Replication initiation requires the function of cyclin-dependent kinases (CDKs), which associate with various cyclin partners to drive cell proliferation. Surprisingly, although we possess detailed knowledge of the CDK regulators and targets that are crucial for origin activation, little is known about whether CDKs play a critical role in establishing the genome-wide pattern of origin selection. We have addressed this question in the fission yeast, taking advantage of a simplified cell cycle network in which cell proliferation is driven by a single cyclin-CDK module. This system allows us to precisely control CDK activity in vivo using chemical genetics. First, in contrast to previous reports, our results clearly show that distinct cyclin-CDK pairs are not essential for regulating specific subsets of origins and for establishing a normal replication program. Importantly, we then demonstrate that the timing at which CDK activity reaches the S phase threshold is critical for the organization of replication in distinct efficiency domains, while the level of CDK activity at the onset of S phase is a dose-dependent modulator of overall origin efficiencies. Our study therefore implicates these different aspects of CDK regulation as versatile mechanisms for shaping the architecture of DNA replication across the genome.
Auteurs, date et publication :
Auteurs Anthony Perrot , Christopher Lee Millington , Blanca Gómez-Escoda , Diane Schausi-Tiffoche , Pei-Yun Jenny Wu
Publication : PLOS Genetics
Date : 2025
Volume : 14
Issue : 2
Pages : e1007214
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Primary consumers in freshwater ecosystems, such as the zooplankton organism Daphnia magna, are highly affected by cyanobacteria, both as they may use it as a food source but also by cyanobacterial metabolites present in the water. Here, we investigate the impacts of cyanobacterial metabolites focussing on the environmental realistic scenario of the naturally released mixture without crushing cyanobacterial cells or their uptake as food. Therefore, D. magna were exposed to two concentrations of cell free cyanobacterial spent medium from Microcystis aeruginosa PCC 7806 to represent higher and lower ecologically-relevant concentrations of cyanobacterial metabolites. Including microcystin-LR, 11 metabolites have been detected of which 5 were quantified. Hypothesising concentration and time dependent negative impact, survival, gene expression marking digestion and metabolism, oxidative stress response, cell cycle and molting as well as activities of detoxification and antioxidant enzymes were followed for 7 days. D. magna suffered from oxidative stress as both catalase and glutathione S-transferase enzyme activities significantly decreased, suggesting enzyme exhaustibility after 3 and 7 days. Moreover, gene-expressions of the 4 stress markers (glutathione S-transferase, glutathione peroxidase, catalase and thioredoxin) were merely downregulated after 7 days of exposure. Energy allocation (expression of Glyceraldehyde-3-phosphate dehydrogenase) was increased after 3 days but decreased as well after 7 days exposure. Cell cycle was impacted time dependently but differently by the two concentrations, along with an increasing downregulation of myosin heavy chain responsible for cell arrangement and muscular movements. Deregulation of nuclear hormone receptor genes indicate that D. magna hormonal steering including molting seemed impaired despite no detection of microviridin J in the extracts. As a consequence of all those responses and presumably of more than investigated molecular and physiological changes, D. magna survival was impaired over time, in a concentration dependent manner. Our results confirm that besides microcystin-LR, other secondary metabolites contribute to negative impact on D. magna survival and stress response.
Auteurs, date et publication :
Auteurs Gorenka Bojadzija Savic , Hervé Colinet , Myriam Bormans , Christine Edwards , Linda A. Lawton , Enora Briand , Claudia Wiegand
Publication : Toxicon
Date : 2021