Publications associées à Differential coral bleaching—Contrasting the activity and response of enzymatic antioxidants in symbiotic partners under thermal stress

Gene expression of Pocillopora damicornis coral larvae in response to acidification and ocean warming

Objectives The endosymbiosis with Symbiodiniaceae is key to the ecological success of reef-building corals. However, climate change is threatening to destabilize this symbiosis on a global scale. Most studies looking into the response of corals to heat str ...

BMC2024

HaloTag-Based Tools for Live-Cell Imaging and Elucidation of Organellar Redox Biology

Sarah Emmert

Redox homeostasis is a key factor in maintaining cellular function and health. The main determinant of the intracellular redox potential is ubiquitous glutathione (GSH) together with its oxidized dimer (GSSG). Importantly, both redox equilibrium and GSH ho ...

EPFL2024

Metabolism of the symbiotic jellyfish Cassiopea in a changing environment

Gaëlle Delphine Toullec

Ocean warming and other anthropogenic impacts have led to a global decline in many photosymbiotic cnidarians, most notably reef-building corals. But some species of the symbiotic and (sub-)tropical upside-down jellyfish Cassiopea are increasingly reported ...

EPFL2023

Photobiology and metabolic interactions in the symbiotic jellyfish Cassiopea

Niclas Heidelberg Lyndby

The symbiont-bearing jellyfish Cassiopea live a benthic lifestyle, positioning themselves upside-down on sediments in shallow waters to allow their endosymbiotic algae to photosynthesize in the sunlight. Over the last decades Cassiopea has become increasin ...

EPFL2023

Excess labile carbon promotes diazotroph abundance in heat-stressed octocorals

Claudia Isabella Pogoreutz

Nitrogen limitation is the foundation of stable coral-algal symbioses. Diazotrophs, prokaryotes capable of fixing N-2 into ammonia, support the productivity of corals in oligotrophic waters, but could contribute to the destabilization of holobiont function ...

ROYAL SOC2023

Non-invasive investigation of the morphology and optical properties of the upside-down jellyfish Cassiopea with optical coherence tomography

Anders Meibom, Sandrine Denise Françoise Bessette, Niclas Heidelberg Lyndby, Michael Kühl

The jellyfish Cassiopea largely cover their carbon demand via photosynthates produced by microalgal endosymbionts, but how holobiont morphology and tissue optical properties affect the light microclimate and symbiont photosynthesis in Cassiopea remain unex ...

ROYAL SOC2023

Symbiotic nutrient exchange enhances the long-term survival of cassiosomes, the autonomous stinging-cell structures of Cassiopea

Cristina Martin Olmos, Anders Meibom, Niclas Heidelberg Lyndby, Gaëlle Delphine Toullec, Nils Rädecker, Claudia Isabella Pogoreutz, Guilhem Maurice Louis Banc-Prandi

Medusae of the widely distributed upside-down jellyfish Cassiopea release autonomous, mobile stinging structures. These so-called cassiosomes play a role in predator defense and prey capture, and are major contributors to “contactless” stinging incidents i ...

2023

Coupled carbon and nitrogen cycling regulates the cnidarian–algal symbiosis

Anders Meibom, Stéphane Laurent Escrig, Nils Rädecker

Efficient nutrient recycling underpins the ecological success of cnidarian-algal symbioses in oligotrophic waters. In these symbioses, nitrogen limitation restricts the growth of algal endosymbionts in hospite and stimulates their release of photosynthates ...

Nature Research2023

Intrinsically High Capacity of Animal Cells From a Symbiotic Cnidarian to Deal With Pro-Oxidative Conditions

Gaëlle Delphine Toullec

The cnidarian-dinoflagellate symbiosis is a mutualistic intracellular association based on the photosynthetic activity of the endosymbiont. This relationship involves significant constraints and requires co-evolution processes, such as an extensive capacit ...

FRONTIERS MEDIA SA2022

Presence of algal symbionts affects denitrifying bacterial communities in the sea anemone Aiptasia coral model

Anders Meibom, Nils Rädecker, Claudia Isabella Pogoreutz

The coral-algal symbiosis is maintained by a constant and limited nitrogen availability in the holobiont. Denitrifiers, i.e., prokaryotes reducing nitrate/nitrite to dinitrogen, could contribute to maintaining the nitrogen limitation in the coral holobiont ...

2022

Contrasting Microbiome Dynamics of Putative Denitrifying Bacteria in Two Octocoral Species Exposed to Dissolved Organic Carbon (DOC) and Warming

Nils Rädecker, Claudia Isabella Pogoreutz

Mutualistic nutrient cycling in the coral-algae symbiosis depends on limited nitrogen (N) availability for algal symbionts. Denitrifying prokaryotes capable of reducing nitrate or nitrite to dinitrogen could thus support coral holobiont functioning by limi ...

2022

Positive interactions between corals and damselfish increase coral resistance to temperature stress

Leïla Ezzat

By the century's end, many tropical seas will reach temperatures exceeding most coral species' thermal tolerance on an annual basis. The persistence of corals in these regions will, therefore, depend on their abilities to tolerate recurrent thermal stress. ...

WILEY2022

High light quantity suppresses locomotion in symbiotic Aiptasia

Anders Meibom, Nils Rädecker, Claudia Isabella Pogoreutz

Many cnidarians engage in endosymbioses with microalgae of the family Symbiodiniaceae. In this association, the fitness of the cnidarian host is closely linked to the photosynthetic performance of its microalgal symbionts. Phototaxis may enable semi-sessil ...

2022

A roadmap to understanding diversity and function of coral reef-associated fungi

Claudia Isabella Pogoreutz

Tropical coral reefs are hotspots of marine productivity, owing to the association of reef-building corals with endosymbiotic algae and metabolically diverse bacterial communities. However, the functional importance of fungi, well-known for their contribut ...

OXFORD UNIV PRESS2022

Green fluorescent protein-like pigments optimise the internal light environment in symbiotic reef-building corals

Niclas Heidelberg Lyndby

Pigments homologous to the green fluorescent protein (GFP) have been proposed to fine-tune the internal light microclimate of corals, facilitating photoacclimation of photosynthetic coral symbionts (Symbiodiniaceae) to life in different reef habitats and e ...

2022

Coral holobiont cues prime Endozoicomonas for a symbiotic lifestyle

Nils Rädecker, Claudia Isabella Pogoreutz, Gabriela Hannah Holligan Perna

Endozoicomonas are prevalent, abundant bacterial associates of marine animals, including corals. Their role in holobiont health and functioning, however, remains poorly understood. To identify potential interactions within the coral holobiont, we character ...

SPRINGERNATURE2022

Overview of oxidative stress findings in hepatic encephalopathy: From cellular and ammonium-based animal models to human data

Cristina Ramona Cudalbu, Dunja Simicic

Oxidative stress is a natural phenomenon in the body. Under physiological conditions intracellular reactive oxygen species (ROS) are normal components of signal transduction cascades, and their levels are maintained by a complex antioxidants systems partic ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Microbes support enhanced nitrogen requirements of coral holobionts in a high CO 2 environment

Nils Rädecker, Gabriela Hannah Holligan Perna

Ocean acidification is posing a threat to calcifying organisms due to the increased energy requirements of calcification under high CO2 conditions. The ability of scleractinian corals to cope with future ocean conditions will thus depend on their ability t ...

2021

Heat stress reduces the contribution of diazotrophs to coral holobiont nitrogen cycling

Anders Meibom, Nils Rädecker, Claudia Isabella Pogoreutz, Gabriela Hannah Holligan Perna

Efficient nutrient cycling in the coral-algal symbiosis requires constant but limited nitrogen availability. Coral-associated diazotrophs, i.e., prokaryotes capable of fixing dinitrogen, may thus support productivity in a stable coral-algal symbiosis but c ...

2022

Heat stress destabilizes symbiotic nutrient cycling in corals

Anders Meibom, Nils Rädecker, Claudia Isabella Pogoreutz

Recurrent mass bleaching events are pushing coral reefs worldwide to the brink of ecological collapse. While the symptoms and consequences of this breakdown of the coral–algal symbiosis have been extensively characterized, our understanding of the underlyi ...

2021