Résumé
Anticipating the genetic and phenotypic changes induced by natural or artificial selection requires reliable estimates of trait evolvabilities (genetic variances and covariances). However, whether or not multivariate quantitative genetics models are able to predict precisely the evolution of traits of interest, especially fitness-related, life history traits, remains an open empirical question. Here, we assessed to what extent the response to bivariate artificial selection on both body size and maturity in the medaka Oryzias latipes, a model fish species, fits the theoretical predictions. Three lines (Large, Small, and Control lines) were differentially selected for body length at 75 days of age, conditional on maturity. As maturity and body size were phenotypically correlated, this selection procedure generated a bi-dimensional selection pattern on two life history traits. After removal of nonheritable trends and noise with a random effect (“animal”) model, the observed selection response did not match the expected bidirectional response. For body size, Large and Control lines responded along selection gradients (larger body size and stasis, respectively), but, surprisingly, the Small did not evolve a smaller body length and remained identical to the Control line throughout the experiment. The magnitude of the empirical response was smaller than the theoretical prediction in both selected directions. For maturity, the response was opposite to the expectation (the Large line evolved late maturity compared to the Control line, while the Small line evolved early maturity, while the opposite pattern was predicted due to the strong positive genetic correlation between both traits). The mismatch between predicted and observed response was substantial and could not be explained by usual sources of uncertainties (including sampling effects, genetic drift, and error in G matrix estimates).
Auteurs, date et publication :
Auteurs Arnaud Le Rouzic , Clémentine Renneville , Alexis Millot , Simon Agostini , David Carmignac , Éric Édeline
Publication : Ecology and Evolution
Date : 2025
Volume : n/a
Issue : n/a
Catégorie(s)
#ANR-Citation #CNRS #ENS #PLANAQUARésumé
Anticipating the genetic and phenotypic changes induced by natural or artificial selection requires reliable estimates of trait evolvabilities (genetic variances and covariances). However, whether or not multivariate quantitative genetics models are able to predict precisely the evolution of traits of interest, especially fitness-related, life-history traits, remains an open empirical question. Here, we assessed to what extent the response to bivariate artificial selection on both body size and maturity in the medaka Oryzias latipes, a model fish species, fits the theoretical predictions. Three populations were selected for divergent body size while maintaining a constant selection pressure against late maturity. The observed evolutionary trends did not match the predictions from a bivariate quantitative genetics "animal" model. The most parsimonious model identified environmental, but not genetic, covariances between both traits, which cannot explain why body size did not evolve in the line selected for a smaller body length. We investigated alternative mechanisms (including genetic drift, inbreeding depression, natural selection, scaling or genetic asymmetry issues, and undetected genetic correlations) but could not attribute the deviation from theory to any single explanation. Overall, these results question the ability of multivariate quantitative models to provide valid and operational predictions of the evolutionary response to multivariate selection on complex traits.
Auteurs, date et publication :
Auteurs Arnaud Le Rouzic , Clémentine Renneville , Alexis Millot , Simon Agostini , David Carmignac , Éric Édeline
Publication : bioRxiv
Date : 2020
Pages : 2020.01.23.916361
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Anthropogenic perturbations such as harvesting often select against a large body size, and are predicted to induce rapid evolution towards smaller body sizes and earlier maturation. However, the evolvability of body size and size-correlated traits remains seldom evaluated in wild populations. Here, we use a laboratory experiment over 6 generations to measure the ability of wild-caught medaka fish (Oryzias latipes) to evolve in response to bidirectional size-dependent selection mimicking opposite harvest regimes. Specifically, we imposed selection against a small body size (Large line), against a large body size (Small line) or random selection (Control line), and measured correlated responses across multiple phenotypic, life-history and endocrine traits. As expected, the Large line evolved faster somatic growth and delayed maturation, but also evolved smaller body sizes at hatch, with no change in average levels of pituitary gene expressions of luteinizing, follicle-stimulating or growth (GH) hormones. In contrast, the Small medaka line was unable to evolve smaller body sizes or earlier maturation, but showed marginally-significant signs of increased reproductive investment (age effect on maturity probability, larger egg sizes, elevated pituitary GH production). Natural selection on medaka body size was too weak to significantly hinder the effect of artificial selection, indicating that the asymmetric body-size response to size-dependent selection reflected an asymmetry in body-size evolvability. Our results show that trait evolvability may be contingent upon the direction of selection, and that a detailed knowledge of trait evolutionary potential is needed to forecast population response to anthropogenic change.
Auteurs, date et publication :
Auteurs Clémentine Renneville , Alexis Millot , Simon Agostini , David Carmignac , Gersende Maugars , Sylvie Dufour , Arnaud Le Rouzic , Eric Edeline
Publication : bioRxiv
Date : 2020
Pages : 498683
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Although irrigation water is frequently assessed for the presence of plant pathogens, large spatial and temporal surveys that provide clues on the diversity and circulation of pathogens is missing. We evaluate the diversity of soft rot Pectobacteriaceae (SRP) of the genera Dickeya and Pectobacterium over two years in a temperate, mixed use watershed. The abundance of isolated strains correlates with the agricultural gradient along the watershed with a positive correlation found with temperature, nitrate and dissolved organic carbon water concentration. We characterized 582 strains by amplification and sequencing of the gapA gene. MLSA analysis performed with 3 housekeeping genes for 99 strains and core genome analysis of 38 sequenced strains confirmed for all the strains but one the taxonomic assignation obtained with the sole gapA sequence. Pectobacterium spp. (549 isolates) were far more abundant than Dickeya spp. (33 isolates). Dickeya spp. were only observed in the lower part of the river when water temperature was above 19°C and we experimentally confirmed a decreased fitness of several Dickeya spp. at 8°C in river water. D. oryzae dominates the Dickeya spp. P. versatile and P. aquaticum dominate the Pectobacterium spp. but their repartition along the watershed was different, P. versatile being the only species regularly recovered all along the watershed. Excepting P. versatile, Dickeya and Pectobacterium spp. responsible for disease outbreak on crops were less abundant or rarely detected. This work sheds light on the various ecological behaviours of different SRP in stream water and indicates that SRP occupation is geographically structured.
Auteurs, date et publication :
Auteurs Hajar Ben Moussa , Claire Bertrand , Emma Rochelle-Newall , Sarah Fiorini , Jacques Pédron , Marie-Anne Barny
Publication : Phytopathology
Date : 2022
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENS #PLANAQUARésumé
An R package to compute DO correction factors for HOBO sensors calibrations, and append new files to old files. Specifically written for PLANAQUA mesocosm lakes, at the CEREEP-Ecotron (France).
Auteurs, date et publication :
Auteurs Rosalie Bruel
Date : 2023
Catégorie(s)
#CNRS #ENS #PLANAQUAAuteurs, date et publication :
Auteurs Ciaran Laverty , Kyle D. Green , Jaimie T. A. Dick , Daniel Barrios-O’Neill , Paul J. Mensink , Vincent Médoc , Thierry Spataro , Joe M. Caffrey , Frances E. Lucy , Pieter Boets , J. Robert Britton , Josephine Pegg , Cathal Gallagher
Publication : Biological Invasions
Date : 2025
Volume : 19
Issue : 5
Pages : 1653-1665
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Freshwater ecosystems are increasingly exposed to pharmaceutical contamination, impacting non-target species. Concentrations can vary over time and location, allowing for potential acclimation or recovery effects. Additionally, parasites might interfere with the absorption and adverse outcomes pathways of pollutants. We examined the combined effects of paracetamol and parasite on the behavior and coloration of the European chub (Squalius cephalus), a ubiquitous fish species, from natural populations. Fish were exposed in mesocosms to acute doses of paracetamol (16 μg g−1 once a day over two days), followed by lower doses during a long-term exposure (1.6 μg g−1 once a week over three weeks), followed by a three-week recovery phase. Acute exposure induced marginal decreases in behavioral activity, and changes in dorsal brightness, hue and UV luminance. Interestingly, the long-term phase alone did not yield notable results on behavior and coloration. However, some effects of the acute exposure persisted during the long-term phase, highlighting that the expression of biological responses may be delayed in relation to past high exposure. Parasitism did not attenuate acute impacts, suggesting parasites may not help mitigate effects of paracetamol on behavior and coloration, but alone increased activity levels slightly. No effects of pollutant exposure, either of the acute or long-term phase, were observed after a recovery phase, indicating ability for recovery dynamics. Overall, our findings emphasize that pollutants effects can be highly transient, with rapid recovery when pollutant exposure ceased. Considering different exposure phases is crucial when assessing the ecological consequences of environmental contaminants.
Auteurs, date et publication :
Auteurs Léa Lorrain-Soligon , Alexis Golven , Simon Agostini , Alexis Millot , Alexandre Bauer , Thierry Rigaud , Beatriz Decencière , Carine Puppo , Aurélie Goutte
Publication : Chemosphere
Date : 2025
Volume : 374
Pages : 144225
Catégorie(s)
#ANR-Citation #CNRS #PLANAQUARésumé
Solute exchange between the sediment and the water column strongly influences water quality in aquatic ecosystems. Among the techniques available for in situ observation, only aquatic eddy covariance (AEC) can resolve the hourly dynamics of benthic fluxes, but only for few substances like oxygen. In micrometeorology, relaxed eddy accumulation (REA), a technique based on high-frequency sampling conditioned by current direction, overcomes this limitation. We developed a portable prototype instrumentation platform to transfer REA to the sediment-water interface of shallow aquatic ecosystems. In order to evaluate the sampling system, we configured the prototype for measuring oxygen fluxes and comparing them to simultaneous AEC measurements. In a river and two artificial lakes, at depths 1–3 m and 0.2 m above the sediment, we measured 15 oxygen flux pairs in fully developed turbulence during 8–15 min periods, ranging from −150 to 50 mmol m−2 day−1. The good agreement between REA and AEC fluxes (R2 = 0.94) shows the reliability of the conditional sampling system. REA represents a promising technique for exploring the sediment contribution to biogeochemical cycles in aquatic ecosystems.
Auteurs, date et publication :
Auteurs Guilherme Calabro-Souza , Andreas Lorke , Christian Noss , Philippe Dubois , Mohamed Saad , Celia Ramos-Sanchez , Brigitte Vinçon-Leite , Régis Moilleron , Magali Jodeau , Bruno J. Lemaire
Publication : Earth and Space Science
Date : 2025
Volume : 10
Issue : 9
Pages : e2023EA003041
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Man-made sounds are now recognized as a pervasive pollutant, and impacts on wildlife have been researched for many years. However, less knowledge is available on certain species, particularly small freshwater invertebrates, which are abundant, highly diversified, and occupy key positions in food webs. Also, it is not clear whether the responses to noise observed at the level of individuals have consequences on communities. A mesocosm investigation was performed to assess the response of a freshwater planktonic community to chronic motorboat noise. Noise was expected to disturb trophic links within the community and particularly the consumption of cladocerans by dipteran larvae. To test this hypothesis, the functional response of Chaoborus larvae feeding on Daphnia was derived, and their behavior during the foraging process was recorded in microcosms (aquariums). Although noise did not induce obvious alteration in the community composition, a significant increase in the abundance of cladocerans was found that was not supported by the results of the microcosm investigation, showing no difference in Chaoborus functional response or behavior between the noisy and noiseless conditions. The results of this chapter suggest that the composition of freshwater zooplankton and particularly cladocerans is likely to be altered by chronic noise, with further investigations needed to understand the mechanisms. They also illustrate how scaling up the effects of noise from individual responses to community remains difficult.
Auteurs, date et publication :
Auteurs Emilie Rojas , Camille Desjonquères , Simon Agostini , Sarah Fiorini , Béatriz Decencière , Michael Danger , Vincent Felten , Vincent Médoc , Arthur N. Popper , Joseph Sisneros , Anthony D. Hawkins , Frank Thomsen
Date : 2025
Pages : 1-17
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
According to theories on cave adaptation, cave organisms are expected to develop a lower metabolic rate compared to surface organisms as an adaptation to food scarcity in the subterranean environments. To test this hypothesis, we compared the oxygen consumption rates of the surface and subterranean populations of a surface-dwelling species, the newt Calotriton asper, occasionally found in caves. In this study, we designed a new experimental setup in which animals with free movement were monitored for several days in a respirometer. First, we measured the metabolic rates of individuals from the surface and subterranean populations, both maintained for eight years in captivity in a natural cave. We then tested individuals from these populations immediately after they were caught and one year later while being maintained in the cave. We found that the surface individuals that acclimated to the cave significantly reduced their oxygen consumption, whereas individuals from the subterranean population maintained in the cave under a light/dark cycle did not significantly modify their metabolic rates. Second, we compared these metabolic rates to those of an obligate subterranean salamander (Proteus anguinus), a surface aquatic Urodel (Ambystoma mexicanum), and a fish species (Gobio occitaniae) as references for surface organisms from different phyla. As predicted, we found differences between the subterranean and surface species, and the metabolic rates of surface and subterranean C. asper populations were between those of the obligate subterranean and surface species. These results suggest that the plasticity of the metabolism observed in surface C. asper was neither directly due to food availability in our experiments nor the light/dark conditions, but due to static temperatures. Moreover, we suggest that this adjustment of the metabolic level at a temperature close to the thermal optimum may further allow individual species to cope with the food limitations of the subterranean environment.
Auteurs, date et publication :
Auteurs Olivier Guillaume , Marine Deluen , Allan Raffard , Olivier Calvez , Audrey Trochet
Publication : Ecology and Evolution
Date : 2025
Volume : 10
Issue : 23
Pages : 12983-12989