Publications associées à A method to disentangle and quantify host anabolic turnover in photosymbiotic holobionts with subcellular resolution

Metabolism of the symbiotic jellyfish Cassiopea in a changing environment

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

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

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

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 cycling enables the long-term survival of Aiptasia in the absence of heterotrophic food sources

Anders Meibom, Nils Rädecker

Phototrophic Cnidaria are mixotrophic organisms that can complement their het- erotrophic diet with nutrients assimilated by their algal endosymbionts. Metabolic mod- els suggest that the translocation of photosynthates and their derivatives from the algae ...

2023

What happens to biomass burning-emitted particles in the ocean? A laboratory experimental approach based on their tracers

Christos Panagiotopoulos

Wildfires, controlled burns, and biofuel combustion (biomass burning or BB) are major contributors to particulate matter in the atmosphere and thus have an impact on climate, human health, and ecosystems. Once emitted, the particulate matter derived from B ...

Elsevier2023

The mesoglea buffers the physico-chemical microenvironment of photosymbionts in the upside-down jellyfish Cassiopea sp

Anders Meibom, Niclas Heidelberg Lyndby, Michael Kühl

IntroductionThe jellyfish Cassiopea has a conspicuous lifestyle, positioning itself upside-down on sediments in shallow waters thereby exposing its photosynthetic endosymbionts (Symbiodiniaceae) to light. Several studies have shown how the photosymbionts b ...

FRONTIERS MEDIA SA2023

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

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

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

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

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

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

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

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

Rapid molecular evolution of Spiroplasma symbionts of Drosophila

Bruno Lemaitre, Florent François Masson

Spiroplasma is a genus of Mollicutes whose members include plant pathogens, insect pathogens and endosymbionts of animals. Spiroplasma phenotypes have been repeatedly observed to be spontaneously lost in Drosophila cultures, and several studies have docume ...

2021

Sub-cellular imaging shows reduced photosynthetic carbon and increased nitrogen assimilation by the non-native endosymbiontDurusdinium trenchiiin the model cnidarian Aiptasia

Anders Meibom

Hosting different symbiont species can affect inter-partner nutritional fluxes within the cnidarian-dinoflagellate symbiosis. Using nanoscale secondary ion mass spectrometry (NanoSIMS), we measured the spatial incorporation of photosynthetically fixed(13)C ...

WILEY2020

Intracellular competition for nitrogen controls dinoflagellate population density in corals

Julia Marie Jeanne Yvonne Bodin, Anders Meibom, Stéphane Laurent Escrig, Maria-Evangelia Giovani, Thomas Krüger, Maoz Fine

The density of dinoflagellate microalgae in the tissue of symbiotic corals is an important determinant for health and productivity of the coral animal. Yet, the specific mechanism for their regulation and the consequence for coral nutrition are insufficien ...

ROYAL SOC2020