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Retrotransposon methylation and activity in wild fish (A. anguilla): A matter of size
2019
Pierron, Fabien | Daffe, Guillemine | Lambert, Patrick | Couture, Patrice | Baudrimont, Magalie | Environnements et Paléoenvironnements OCéaniques (EPOC) ; Observatoire aquitain des sciences de l'univers (OASU) ; Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) | Ecosystèmes aquatiques et changements globaux (UR EABX) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Centre Eau Terre Environnement [Québec] (INRS - ETE) ; Institut National de la Recherche Scientifique [Québec] (INRS) | ANR-16-CE34-0008,TRACE,Effets transgénérationnels des polluants chez les poissons: l'épigénétique et son implication en écotoxicologie(2016)
[Departement_IRSTEA]Eaux [ADD1_IRSTEA]Systèmes aquatiques soumis à des pressions multiples | International audience | Understanding how organisms cope with global change is a major question in many fields of biology. Mainly, understanding the molecular mechanisms supporting rapid phenotypic changes of organisms in response to stress and linking stress-induced molecular events to adaptive or adverse outcomes at the individual or population levels remain a major challenge in evolutionary biology, ecology or ecotoxicology. In this view, the present study aimed to test (i) whether environmental factors, especially pollutants, can trigger changes in the activity of retrotransposons (RTs) in wild fish and (ii) if changes in RT DNA methylation or transcription levels can be linked to modifications at the individual level. RTs are genetic elements that have the ability to replicate and integrate elsewhere in the genome. Although RTs are mainly quiescent during normal development, they can be experimentally activated under life-threatening conditions, affecting the fitness of their host. Wild eels were collected in four sampling sites presenting differing levels of contamination. The methylation level and the transcriptional activity of two RTs and two genes involved in development and cell differentiation were analyzed in fish liver in addition to the determination of fish contaminants levels and diverse growth and morphometric indices. An up-regulation of RTs associated to lower methylation levels and lower growth indices were observed in highly contaminated fish. Our results suggest that RT activation in fish experiencing stress conditions could have both detrimental and beneficial implications, affecting fish growth but promoting resistance to environmental stressors such as pollutants. Retrotransposons could represent interesting environment-sensitive molecular markers allowing to link stress-induced molecular events to adverse outcomes at higher levels.
Afficher plus [+] Moins [-]Structure and fate of a Pseudomonas aeruginosa population originating from a combined sewer and colonizing a wastewater treatment lagoon
2014
Lavenir, Raphaël | M.-C Petit, Stéphanie | Alliot, Nolwenn | Ribun, Sébastien | Loiseau, Laurence | Marjolet, Laurence | Briolay, Jérôme | Nazaret, Sylvie | Cournoyer, Benoit | Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM) ; Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS) | Centre de génétique et de physiologie moléculaire et cellulaire (CGPhiMC) ; Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
International audience | The efficacy of a wastewater treatment lagoon (WWTL) at preventing the spread of Pseudomonas aeruginosa into natural aquatic habitats was investigated. A WWTL and its connected combined sewer and brook were exhaustively sampled. Physico-chemical analyses showed a stratification of the first pond according to pH, temperature and oxygen content. The P. aeruginosa counts partially matched this stratification with higher values among the bottom anaerobic waters of the first half of this pond. Genotyping of 494 WWTL P. aeruginosa strains was performed and led to the definition of 85 lineages. Dominant lineages were observed, with some being found all over the WWTL including the connected brook. IS5 was used as an indicator of genomic changes, and 1 to 12 elements were detected among 16 % of the strains. IS-driven lasR (genetic regulator) disruptions were detected among nine strains that were not part of the dominant lineages. These insertional mutants did not show significant elastase activities but showed better growth than the PAO1 reference strain in WWTL waters. Differences in growth patterns were related to a better survival of these mutants at an alkaline pH and a better ability at using some C-sources such as alanine. The opportunistic colonization of a WWTL by P. aeruginosa can involve several metabolic strategies which appeared lineage specific. Some clones appeared more successful than others at disseminating from a combined sewer toward the overflow of a WWTL.
Afficher plus [+] Moins [-]Cytochrome P4501A and other enzymes as molecular biomarkers for use in pollution monitoring
1995
Livingstone, D.R. (National Environment Research Council, Plymouth (Royaume Uni). Plymouth Marine Laboratory)
Measurement of MFO [mixed function oxidase] levels in roach as a biomarker of PAH [polycyclic aromatic hydrocarbons] levels in freshwater systems in UK
1995
O'Hare, D.B. (University of Derby (Royaume Uni). School of Environmental and Applied Sciences, Department of Biology) | Siddall, R. | Gill, R.A. | Robotham, P.W.J.