Publications by authors named "Veronique Berteaux-Lecellier"

One of the main challenges in coral reef conservation and restoration is the identification of coral populations resilient under global warming. Seascape genomics is a powerful tool to uncover genetic markers potentially involved in heat tolerance among large populations without prior information on phenotypes. Here, we aimed to provide first insights on the role of candidate heat associated loci identified using seascape genomics in driving the phenotypic response of Acropora millepora from New Caledonia to thermal stress.

View Article and Find Full Text PDF

Adaptation of reef-building corals to global warming depends upon standing heritable variation in tolerance traits upon which selection can act. Yet limited knowledge exists on heat-tolerance variation among conspecific individuals separated by metres to hundreds of kilometres. Here, we performed standardized acute heat-stress assays to quantify the thermal tolerance traits of 709 colonies of from 13 reefs spanning 1060 km (9.

View Article and Find Full Text PDF

Dinoflagellates are important primary producers known to form Harmful Algae Blooms (HABs). In water, nutrient availability, pH, salinity and anthropogenic contamination constitute chemical stressors for them. The emergence of OMICs approaches propelled our understanding of dinoflagellates' responses to stressors.

View Article and Find Full Text PDF

Anomalous heat waves are causing a major decline of hard corals around the world and threatening the persistence of coral reefs. There are, however, reefs that have been exposed to recurrent thermal stress over the years and whose corals appear to have been tolerant against heat. One of the mechanisms that could explain this phenomenon is local adaptation, but the underlying molecular mechanisms are poorly known.

View Article and Find Full Text PDF
Article Synopsis
  • Anomalous heat waves are threatening coral reefs globally, prompting the need to find coral populations that can withstand thermal stress.
  • A seascape genomics framework was used to study thermal adaptation and connectivity in New Caledonia's coral reefs, combining remote sensing and genomic data from three coral species.
  • Findings showed that reefs predicted to have high adaptation and connectivity had lower coral cover loss after heat stress, suggesting these indicators can guide conservation efforts.
View Article and Find Full Text PDF

Coral reefs are suffering a major decline due to the environmental constraints imposed by climate change. Over the last 20 years, three major coral bleaching events occurred in concomitance with anomalous heatwaves, provoking a severe loss of coral cover worldwide. The conservation strategies for preserving reefs, as they are implemented now, cannot cope with global climatic shifts.

View Article and Find Full Text PDF

Dimethylsulfoniopropionate (DMSP) is a key compound in the marine sulfur cycle, and is produced in large quantities in coral reefs. In addition to Symbiodiniaceae, corals and associated bacteria have recently been shown to play a role in DMSP metabolism. Numerous ecological studies have focused on DMSP concentrations in corals, which led to the hypothesis that increases in DMSP levels might be a general response to stress.

View Article and Find Full Text PDF

Background: Giant clams and scleractinian (reef-building) corals are keystone species of coral reef ecosystems. The basis of their ecological success is a complex and fine-tuned symbiotic relationship with microbes. While the effect of environmental change on the composition of the coral microbiome has been heavily studied, we know very little about the composition and sensitivity of the microbiome associated with clams.

View Article and Find Full Text PDF

DNA methyltransferases are ubiquitous enzymes conserved in bacteria, plants and opisthokonta. These enzymes, which methylate cytosines, are involved in numerous biological processes, notably development. In mammals and higher plants, methylation patterns established and maintained by the cytosine DNA methyltransferases (DMTs) are essential to zygotic development.

View Article and Find Full Text PDF
Article Synopsis
  • High-throughput sequencing is enhancing our understanding of the Symbiodiniaceae group, which is vital for coral reef ecosystems, but many studies rely on a single genetic marker, risking overlooked ecological details.
  • The study tested a dual-index sequencing method on giant clam samples from French Polynesia, enabling the simultaneous analysis of multiple genetic markers without incurring extra costs.
  • Results indicated this method successfully captured diverse genetic information and phylogenetic resolutions, making it a scalable and cost-effective way to assess Symbiodiniaceae biodiversity.
View Article and Find Full Text PDF

One of the mechanisms of rapid adaptation or acclimatization to environmental changes in corals is through the dynamics of the composition of their associated endosymbiotic Symbiodiniaceae community. The various species of these dinoflagellates are characterized by different biological properties, some of which can confer stress tolerance to the coral host. Compelling evidence indicates that the corals' Symbiodiniaceae community can change via shuffling and/or switching but the ecological relevance and the governance of these processes remain elusive.

View Article and Find Full Text PDF

To prevent the settlement and/or the growth of fouling organisms (i.e. bacteria, fungi or microalgae), benthic sessile species have developed various defense mechanisms among which the production of chemical molecules.

View Article and Find Full Text PDF

Lack of wastewater treatment efficiency causes receiving seawaters and bivalve molluscan shellfish to become contaminated, which can lead to public health issues. Six wastewater samples, five seawater samples and three batches of giant clams from Tahiti (French Polynesia) were investigated for the presence of enteric viruses, but also if present, for the diversity, infectivity and integrity of human adenoviruses (HAdV). Enteroviruses (EV), sapoviruses (SaV) and human polyomaviruses (HPyV) were detected in all wastewater samples.

View Article and Find Full Text PDF

Marine ecosystems are both stressed and threatened by pesticides that are used on land. Nevertheless, research on the impact of pesticides on coral reefs and the underlying mechanisms is still in its infancy. The insecticide chlordecone is a persistent organic pollutant with carcinogenic effects in rats and mice.

View Article and Find Full Text PDF

Intracolonial genotypic variability is described in many colonial organisms and arises from mosaicism (somatic mutation) and/or chimerism (allogenic fusion). Both processes provide an additional source of genotypic variation in natural populations and raise questions on the biological significance of colonies having more than one genotype. Using fifteen microsatellite markers, we screened for potential genetic heterogeneity within Millepora platyphylla colonies, a hydrocoral species known for its extensive morphological plasticity among reef habitats.

View Article and Find Full Text PDF

Quantifying the genetic diversity in natural populations is crucial to address ecological and evolutionary questions. Despite recent advances in whole-genome sequencing, microsatellite markers have remained one of the most powerful tools for a myriad of population genetic approaches. Here, we used the 454 sequencing technique to develop microsatellite loci in the fire coral , an important reef-builder of Indo-Pacific reefs We tested the cross-species amplification of these loci in five other species of the genus and analysed its success in correlation with the genetic distances between species using mitochondrial 16S sequences.

View Article and Find Full Text PDF
Article Synopsis
  • The adaptive bleaching hypothesis (ABH) suggests that coral bleaching can positively influence coral survival by allowing corals to switch their algal symbionts based on environmental conditions.
  • Researchers employed quantitative PCR (qPCR) technology to analyze five coral species from Moorea, discovering each species had a primary algal clade but also associated with additional clades at low levels.
  • Notably, clade B was identified as a coral symbiont for the first time in the region, indicating a greater diversity of symbiotic relationships and suggesting that corals in French Polynesia may strategically maintain multiple clades for better environmental adaptability.
View Article and Find Full Text PDF
Article Synopsis
  • Temperature impacts membrane fluidity, influencing cellular and physiological functions, which this study explores in the marine clam Tridacna maxima under thermal stress.
  • The giant clams have a high percentage of saturated fatty acids due to their tropical habitat, yet their total lipid content remains stable despite stress, with compositional changes occurring.
  • Stress triggers changes in fatty acid diversity and boosts gene activity related to lipids and reactive oxygen species; meanwhile, thermal stress causes sequential cell death in their symbiotic partner, Symbiodinium, potentially providing energy to the clams.
View Article and Find Full Text PDF
Article Synopsis
  • Coral disease outbreaks have risen significantly in the past 30 years, but the specific causes are still largely unknown, prompting a 14-month survey of coral colonies.
  • The study utilized a bimonthly qPCR method to assess the relationship between Symbiodinium clades and disease susceptibility, revealing that corals with clade D had a better chance of resisting infection by the pathogenic bacteria Vibrio spp.
  • Findings indicated that Vibrio spp. was only present in diseased colonies, hinting at its opportunistic behavior, and suggested that coral health is more dependent on the initial set of Symbiodinium than on adapting to stress by acquiring new clades.
View Article and Find Full Text PDF
Article Synopsis
  • * It is a global initiative that aims to generate a large and standardized data set through a coordinated effort on a single day.
  • * The commentary discusses the Consortium's goals for studying marine microbial communities and preserving their functional traits sustainably.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the symbiotic relationships between marine invertebrates, specifically nudibranchs and sponges, and the dinoflagellate Symbiodinium, important for ecosystem health in nutrient-demanding habitats like coral reefs.
  • Researchers collected samples from Moorea and Tahiti between 2011 and 2013, sequencing parts of the Symbiodinium 28S rDNA and host mitochondrial COI to analyze these associations.
  • Findings show that while some sponges and nudibranchs contain known Symbiodinium species from clades B and C, others have new, unidentified dinoflagellates; additionally, evidence suggests a unique transfer method of the symbiont between the nudibranch
View Article and Find Full Text PDF

The co-authors of this paper hereby state their intention to work together to launch the Genomic Observatories Network (GOs Network) for which this document will serve as its Founding Charter. We define a Genomic Observatory as an ecosystem and/or site subject to long-term scientific research, including (but not limited to) the sustained study of genomic biodiversity from single-celled microbes to multicellular organisms.An international group of 64 scientists first published the call for a global network of Genomic Observatories in January 2012.

View Article and Find Full Text PDF

Tropical scleractinian corals are considered autotrophic as they rely mainly on photosynthesis-derived nutrients transferred from their photosymbionts. Corals are also able to capture and ingest suspended particulate organic matter, so heterotrophy can be an important supplementary trophic pathway to optimize coral fitness. The aim of this in situ study was to elucidate the trophic status of 10 coral species under contrasted environmental conditions in a French Polynesian lagoon.

View Article and Find Full Text PDF

Peroxisomes are versatile and dynamic organelles that are essential for the development of most eukaryotic organisms. In fungi, many developmental processes, such as sexual development, require the activity of peroxisomes. Sexual reproduction in fungi involves the formation of meiotic-derived sexual spores, often takes place inside multicellular fruiting bodies and requires precise coordination between the differentiation of multiple cell types and the progression of karyogamy and meiosis.

View Article and Find Full Text PDF

Higher fungi, which comprise ascomycetes and basidiomycetes, play major roles in the biosphere. Their evolutionary success may be due to the extended dikaryotic stage of their life cycle, which is the basis for their scientific name: the Dikarya. Dikaryosis is maintained by similar structures, the clamp in basidiomycetes and the crozier in ascomycetes.

View Article and Find Full Text PDF