Transgenerational epigenetic sex determination: Environment experienced by female zebrafish affects offspring sex ratio
Sex determination is a complex process that can be influenced by environment in various taxa. Disturbed environments can affect population sex ratios and thus threaten their viability. Emerging evidences support a role of epigenetic mechanisms, notably DNA methylation, in environmental sex determination (ESD). In this work, using zebrafish as model and a transgenerational experiment comprising 4 successive generations, we report a strength link between the promotor methylation level of three genes in female gonads and population sex ratio. One generation of zebrafish was exposed throughout its lifetime to cadmium (Cd), a non-essential metal, at an environmentally relevant concentration. The subsequent generations were not exposed. At the first and the third generation a subset of individuals was exposed to an elevated temperature, a well-known masculinizing factor in zebrafish. While heat was associated to an increase in the methylation level of cyp19a1a gene and population masculinization, foxl2a/dmrt1 methylation levels appeared to be influenced by Cd and fish density leading to offspring feminization. Ancestral Cd exposure indeed led to a progressive feminization of the population over generations and affected the sex plastic response of zebrafish in response to heat. The effect of Cd on the methylation level of foxl2a was observed until the third generation, supporting potential transgenerational inheritance. Our results support (i) a key role of cyp19a1a methylation in SD in zebrafish in response to environmental cues and (ii) the fact that the environment experienced by parents, namely mothers in the present case, can affect their offspring sex ratio via environment-induced DNA methylation changes in gonads.
(Environmental Pollution. vol. 277, n° 0269-7491, pp. 116864, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UB, BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, CNRS
Peer Community In… A free recommendation process of preprints based on peer reviews
(02/09/2026)
UMR CBGP, Cirad, UM, IRD [Occitanie], IRD, INRAE, Institut Agro, ISA, UNS, CNRS, INRAE, UniCA, DipSO, INRAE, ECOSYS, INRAE, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Latitudinal influence on gametogenesis and host–parasite ecology in a marine bivalve model
Reproduction and parasites have significant impacts on marine animal populations globally. This study aimed to investigate the associative effects of host reproduction and a host–parasite interplay on a marine bivalve, along a geographic gradient of latitude. Cockles Cerastoderma edule were sampled from five European sites (54°N to 40°N), between April 2018 and October 2019. A histological survey provided data on trematode (metacercaria and sporocyst life stages), prevalence, and cockle stage of gametogenesis to assess the influence of a latitudinal gradient on both interplays. Sex ratios at the northernmost sites were skewed toward females, and spawning size was reduced at the lower latitudes. Trematode infection did not follow a latitudinal gradient. Localized site-related drivers, namely seawater temperature, varied spatially, having an impact on cockle–trematode interactions. Spawning was related to elevated temperatures at all sites. Prolonged spawning occurred at southern latitudes, where seawater temperatures were warmer. Trematode prevalence and the impact of trematodes on gametogenesis were found to be spatially variable, but not latitudinally. Therefore, it is not possible to determine the likelihood of boom and bust events in cockles, based on the latitudinal location of a population. In terms of sublethal impacts, it appeared that energy was allocated to reproduction rather than somatic growth in southern populations, with less energy allocated to reproduction in the larger, northern cockles. The demonstrated spatial trend of energy allocation indicates the potential of a temporal trend of reduced cockle growth at northern sites, as a result of warming sea temperatures. This awareness of the spatially varying drivers of populations is crucial considering the potential for these drivers/inhibitors to be exacerbated in a changing marine environment.
(Ecology and Evolution. vol. 11, pp. 7029-7041, 02/09/2026)
UCC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The Terebelliformia-Recent Developments and Future Directions
(Diversity. vol. 13, n° 1424-2818, pp. 60, 02/09/2026)
IO-USP, USP, IB, USP, LECOB, SU, CNRS, OOB, SU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
On the risk of abrupt changes in the North Atlantic subpolar gyre in CMIP6 models
CMIP5 models have been shown to exhibit rapid cooling events in their projections of the North Atlantic subpolar gyre. Here, we analyze the CMIP6 archive, searching for such rapid cooling events in the new generation of models. Four models out of 35 exhibit such instabilities. The climatic impacts of these events are large on decadal timescales, with a substantial effect on surface temperature over Europe, precipitation pattern in the tropics—most notably the Sahel and Amazon regions—and a possible impact on the mean atmospheric circulation. The mechanisms leading to these events are related to the collapse of deep convection in the subpolar gyre, modifying profoundly the oceanic circulation. Analysis of stratification in the subpolar gyre as compared with observations highlights that the biases of the models explain relatively well the spread in their projections of surface temperature trends: models showing the smallest stratification biases over the recent period also show the weakest warming trends. The models exhibiting abrupt cooling rank among the 11 best models for this stratification indicator, leading to a risk of encountering an abrupt cooling event of up to 36.4%, slightly lower than the 45.5% estimated in CMIP5 models.
(Annals of the New York Academy of Sciences. vol. 1504, n° 0077-8923, pp. 187-201, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LMD, INSU - CNRS, X, IP Paris, ENPC, SU, CNRS, ENS-PSL, PSL, LOCEAN-VARCLIM, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, IHOI
Cell and tissue level responses in mussels Mytilus galloprovincialis dietarily exposed to PVP/PEI coated Ag nanoparticles at two seasons
Silver nanoparticles (Ag NPs) are present in numerous consumer products due to their antimicrobial and other unique properties, thus concerns about their potential input into aquatic ecosystems are increasing. Toxicity of Ag NPs in waterborne exposed aquatic organisms has been widely investigated, but studies assessing the potential toxic effects caused after ingestion through the food web, especially at low realistic concentrations, remain scarce. Moreover, it is not well known whether season may influence toxic effects of Ag NPs. The main objective of this study was to determine cell and tissue level responses in mussels Mytilus galloprovincialis dietarily exposed to poly-N-vinyl-2-pirrolidone/polyethyleneimine (PVP/PEI) coated 5 nm Ag NPs for 1, 7 and 21 days both in autumn and spring. Mussels were fed every day with microalgae Isochrysis galbana exposed for 24 h to a low dose (1 μg Ag/L Ag NPs) in spring and to a higher dose (10 μg Ag/L Ag NPs) in spring and autumn. Mussels fed with microalgae exposed to the high dose accumulated Ag significantly after 21 days in both seasons, higher levels being measured in autumn compared to spring. Intralysosomal metal accumulation measured in mussel digestive gland and time- and dose-dependent reduction of mussels health status was similar in both seasons. DNA strand breaks increased significantly in hemocytes at both exposure doses along the 21 days in spring and micronuclei frequency showed an increasing trend after 1 and 7 days of exposure to 1 μg Ag/L Ag NPs in spring and to 10 μg Ag/L in both seasons. Values decreased after 21 days of exposure in all the cases. In conclusion, PVP/PEI coated 5 nm Ag NPs ingested through the food web were significantly accumulated in mussel tissues and caused adverse cell and tissue level effects both in autumn and in spring.
(Science of the Total Environment. vol. 750, n° 0048-9697, pp. 141303, 02/09/2026)
UPV / EHU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Les plans d'eau face aux changements climatiques
Ces milieux aquatiques fournissent de nombreux services écosystémiques, en assurant des fonctions de support (production primaire, biodiversité), de régulation (épuration des nutriments, régulation des flux hydriques), d’approvisionnement (eau potable, irrigation, énergie) et socio-culturels (loisir, tourisme). Souvent perçus à tort comme immuables, stables et en dehors de toute pression, les plans d’eau font l’objet de multiples usages anthropiques, impactant leur fonctionnement. Le changement climatique en cours ne fait qu’exacerber ces impacts et accélérer la dégradation des milieux ; à l’échelle régionale, ses effets restent encore à évaluer. Dans cet ouvrage, nous avons souhaité illustrer, de la manière la plus large possible, la variété des systèmes lentiques présents en Nouvelle-Aquitaine, ainsi que les lacunes de connaissance que diverses études mettent en évidence. Le but de cet ouvrage est d’apporter des éclairages scientifiques pour l’aide à la décision et aux choix politiques, et d’accompagner l’appropriation citoyenne des connaissances. Notre souhait ultime serait que ces lieux emblématiques, source de bien-être et de services, puissent continuer à recouvrir leurs rôles fonctionnels dans le futur.
(pp. 56, 02/09/2026)
Bordeaux INP, UBM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CARRTEL, USMB [Université de Savoie] [Université de Chambéry], INRAE, Fédération OSUG, CEDETE, UO, UR EABX, INRAE, BRGM, ENSEGID, IRSTEA, E2Lim, IMPEO, UNILIM, ECOBIO, UR, INEE-CNRS, CNRS, CNRS, IPSL (FR_636), ENS-PSL, PSL, UVSQ, CEA, INSU - CNRS, X, IP Paris, CNES, SU, CNRS, UPCité, IRSTEA, DIRSE, RURALITES [Poitiers], UP
The Seine River Basin
Among the six hydrographic basins of metropolitan France, the Seine-Normandy basin is the most human-impacted. This territory of 76,000 km 2 and 17 million people receives the highest anthropogenic pressure, due to its industrial and agri- cultural activities linked to the development of the urban area of Paris, which has been and still is the economic and social heart of France. These pressures have gradually impacted the hydrological, chemical, and ecological functioning of the basin, leading to a maximum chemical degradation between the 1960s and the 1990s. The very poor chemical and ecological status of water bodies in the 1980s led a small group of researchers to propose a PIREN-Seine, i.e. an interdisciplinary environmental research program created by the French National Centre for Scien- tific Research (CNRS). This program was launched in 1989 in the context of insufficient wastewater treatment in the Paris conurbation. Its first achievement consisted in developing models to better understand the river hydrological and biogeochemical functioning. These tools have made it possible to bring together research teams on a common object of study, the whole Seine watershed; the program has also been a forum for dialogue between the basin ’ s institutional partners and researchers, enabling the latter to make management proposals to establish investment priorities based on the results of these models. Over the past 30 years, the PIREN-Seine program has grown up, has attracted social scientists, and has generated a vast number of disciplinary and interdisci- plinary publications, more than 100 PhD theses, hundreds of publications in scientific journals, and as many communications in international workshops and conferences. Nevertheless, the collective visibility of this group of scientists and institutional partners is still relatively low internationally, since most publication credits are given to individuals, to their laboratories, or to their research institutions. Moreover, the names of these laboratories and institutions have also evolved over time, making the recognition of this collective effort even more difficult. This book is the opportunity to present the most salient or recent results of the program, presented here as trajectories that relate environmental changes, societal changes, and the state of the Seine River basin waterbodies, which is nowadays largely controlled by the balance between pressures, water and river uses, and social responses. The book covers a broad range of topics such as (1) the estimation of fluxes transported from headwaters to the coastal zone, at a very fine spatial scale, using models, (2) long-term analyses (50–200 years) of the socio-ecosystem Seine, using archives, retro and prospective modeling, (3) the identification and quantification of sources and transfer of a wide variety of elements and pollutants (nutrients, carbon, trace metals, POPs, pharmaceuticals, pesticides, microplastics, etc.), (4) the study of microbial contaminations, and (5) the analysis of the impact of water quality and contaminations on biota. Studies considering the Seine River basin as a socio-ecological system are increasingly present within the PIREN-Seine program, which has been included in the Zone Atelier Seine (ZA Seine). The latter coordinates the research activities on the Paris city, the Seine River basin, and the Seine River estuary. It is also part of the European Long-Term Socio-Economic and Ecosystem Research (LTSER) pro- grams. The large size of the basin and the longue-dure´e approach (up to 200 years) make this territory a rare and fully documented example of the multiple and evolving interrelations between a river, its large basin and their society which characterize the Anthropocene era.
(. vol. 90, 02/09/2026)
GEOSCIENCES, PSL, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, METIS, EPHE, PSL, INSU - CNRS, SU, CNRS
Climate and the Evolution of the Ocean: The Paleoceanographic Data
The idea of reconstructing the history of oceans and climates in the past using marine sediment cores arrived quite late after the beginnings of oceanography. It was initiated in the twentieth century, well after the first attempts to measure variations in seawater temperature down the water column, which date back to the eighteenth century with the great circumnavigation expeditions. Land geologists were the first to propose paleoceanographic reconstructions from exposed marine series, limiting the collected information to former coastal waters.
(pp. 225-254, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, IFREMER, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LGO, UBS, IFREMER, UBO EPE, CNRS
Effect of light on the trematode Himasthla elongata: from cercarial behaviour to infection success
The cockle Cerastoderma edule, a socioeconomically important bivalve of the northeast Atlantic, is host to several trematodes, including Himasthla elongata. In the life cycle of this trematode, cercariae (free-living stages) emerge from the first intermediate host, a snail, to infect cockles as second intermediate hosts. During their lifespan (less than 2 d), cercariae must ensure successful host-to-host transmission via the surrounding water and therefore are exposed to and impacted by different environmental conditions, including abiotic factors. Given that the light:dark cycle is one of the major drivers of behaviour in aquatic habitats, we aimed to determine the influence of light on cercariae and host behaviour based on 3 hypotheses. First, by having a benthic second intermediate host, these cercariae will display a photonegative orientation; second, and conversely, host behaviour will not be influenced by light; and third, cercariae infection success will be light-dependent. Results showed that cercariae display a photopositive orientation (first hypothesis rejected), displaying movements towards light. Host activity (evaluated by oxygen consumption) was similar among conditions, i.e. dark vs. light (second hypothesis accepted), but hosts acquired more parasites when experimentally infected in the dark (third hypothesis accepted). This light-dependent infection of the host is explained by a change of cercarial behaviour when exposed to light, decreasing their infection success. This study highlights that trematode responses to external conditions may be linked to successful life cycle completion rather than being altered by the host habitat. Light influence on cercarial behaviour resulted in increased infection success that may affect trematode population dynamics and their distributional range.
(Diseases of Aquatic Organisms. vol. 146, n° 0177-5103, pp. 23-28, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS