A DNA barcode-based survey of terrestrial arthropods in the Society Islands of French Polynesia : host diversity within the SymbioCode Project

We report here on the taxonomic and molecular diversity of 10 929 terrestrial arthropod specimens, collected on four islands of the Society Archipelago, French Polynesia. The survey was part of the 'SymbioCode Project' that aims to establish the Society Islands as a natural laboratory in which to investigate the flux of bacterial symbionts (e.g., Wolbachia) and other genetic material among branches of the arthropod tree. The sample includes an estimated 1127 species, of which 1098 included at least one DNA-barcoded specimen and 29 were identified to species level using morphological traits only. Species counts based on molecular data emphasize that some groups have been understudied in this region and deserve more focused taxonomic effort, notably Diptera, Lepidoptera and Hymenoptera. Some taxa that were also subjected to morphological scrutiny reveal a consistent match between DNA and morphology-based species boundaries in 90% of the cases, with a larger than expected genetic diversity in the remaining 10%. Many species from this sample are new to this region or are undescribed. Some are under description, but many await inspection by motivated experts, who can use the online images or request access to ethanol-stored specimens.Peer reviewe

Δ133p53β isoform pro-invasive activity is regulated through an aggregation-dependent mechanism in cancer cells

International audienceAbstract The p53 isoform, Δ133p53β, is critical in promoting cancer. Here we report that Δ133p53β activity is regulated through an aggregation-dependent mechanism. Δ133p53β aggregates were observed in cancer cells and tumour biopsies. The Δ133p53β aggregation depends on association with interacting partners including p63 family members or the CCT chaperone complex. Depletion of the CCT complex promotes accumulation of Δ133p53β aggregates and loss of Δ133p53β dependent cancer cell invasion. In contrast, association with p63 family members recruits Δ133p53β from aggregates increasing its intracellular mobility. Our study reveals novel mechanisms of cancer progression for p53 isoforms which are regulated through sequestration in aggregates and recruitment upon association with specific partners like p63 isoforms or CCT chaperone complex, that critically influence cancer cell features like EMT, migration and invasion

Comprendre la mondialisation II

Après l'économie, nous continuons à explorer les multiples composants de la mondialisation. Des analystes politiques nous éclairent sur les mutations en cours : le rôle des États face à l'émancipation des forces économiques, le jeu des organisations supranationales, l'avenir de la démocratie à l'ère du global, les formes d'appropriation ou de rejet de la mondialisation par les citoyens... Citoyens du monde, mondialité... L'explosion des nouvelles technologies de l'information et de la communi..

Epigenome-associated phenotypic acclimatization to ocean acidification in a reef-building coral

There are increasing concerns that the current rate of climate change might outpace the ability of reef-building corals to adapt to future conditions. Work on model systems has shown that environmentally induced alterations in DNA methylation can lead to phenotypic acclimatization. While DNA methylation has been reported in corals and is thought to associate with phenotypic plasticity, potential mechanisms linked to changes in whole-genome methylation have yet to be elucidated. We show that DNA methylation significantly reduces spurious transcription in the coral Stylophora pistillata. Furthermore, we find that DNA methylation also reduces transcriptional noise by fine-tuning the expression of highly expressed genes. Analysis of DNA methylation patterns of corals subjected to long-term pH stress showed widespread changes in pathways regulating cell cycle and body size. Correspondingly, we found significant increases in cell and polyp sizes that resulted in more porous skeletons, supporting the hypothesis that linear extension rates are maintained under conditions of reduced calcification. These findings suggest an epigenetic component in phenotypic acclimatization that provides corals with an additional mechanism to cope with environmental change.This publication is based on work supported by the KAUST Office of Sponsored Research under award no. FCC/1/1973- 22-01. Part of this study was conducted as part of the Centre Scientifique de Monaco Research Program, which is supported by the Government of the Principality of Monaco

The Tara Pacific expedition—A pan-ecosystemic approach of the “-omics” complexity of coral reef holobionts across the Pacific Ocean

Coral reefs are the most diverse habitats in the marine realm. Their productivity, structural complexity, and biodiversity critically depend on ecosystem services provided by corals that are threatened because of climate change effects—in particular, ocean warming and acidification. The coral holobiont is composed of the coral animal host, endosymbiotic dinoflagellates, associated viruses, bacteria, and other microeukaryotes. In particular, the mandatory photosymbiosis with microalgae of the family Symbiodiniaceae and its consequences on the evolution, physiology, and stress resilience of the coral holobiont have yet to be fully elucidated. The functioning of the holobiont as a whole is largely unknown, although bacteria and viruses are presumed to play roles in metabolic interactions, immunity, and stress tolerance. In the context of climate change and anthropogenic threats on coral reef ecosystems, the Tara Pacific project aims to provide a baseline of the “-omics” complexity of the coral holobiont and its ecosystem across the Pacific Ocean and for various oceanographically distinct defined areas. Inspired by the previous Tara Oceans expeditions, the Tara Pacific expedition (2016–2018) has applied a pan-ecosystemic approach on coral reefs throughout the Pacific Ocean, drawing an east–west transect from Panama to Papua New Guinea and a south–north transect from Australia to Japan, sampling corals throughout 32 island systems with local replicates. Tara Pacific has developed and applied state-of-the-art technologies in very-high-throughput genetic sequencing and molecular analysis to reveal the entire microbial and chemical diversity as well as functional traits associated with coral holobionts, together with various measures on environmental forcing. This ambitious project aims at revealing a massive amount of novel biodiversity, shedding light on the complex links between genomes, transcriptomes, metabolomes, organisms, and ecosystem functions in coral reefs and providing a reference of the biological state of modern coral reefs in the Anthropocene

Oxia Planum: The Landing Site for the ExoMars “Rosalind Franklin” Rover Mission: Geological Context and Prelanding Interpretation

The European Space Agency (ESA) and Roscosmos ExoMars mission will launch the “Rosalind Franklin” rover in 2022 for a landing on Mars in 2023.The goals of the mission are to search for signs of past and present life on Mars, investigate the water/geochemical environment as a function of depth in the shallow subsurface, and characterize the surface environment. To meet these scientific objectives while minimizing the risk for landing, a 5-year-long landing site selection process was conducted by ESA, during which eight candidate sites were down selected to one: Oxia Planum. Oxia Planum is a 200 km-wide low-relief terrain characterized by hydrous clay-bearing bedrock units located at the southwest margin of Arabia Terra. This region exhibits Noachian-aged terrains. We show in this study that the selected landing site has recorded at least two distinct aqueous environments, both of which occurred during the Noachian: (1) a first phase that led to the deposition and alteration of ∼100 m of layered clay-rich deposits and (2) a second phase of a fluviodeltaic system that postdates the widespread clay-rich layered unit. Rounded isolated buttes that overlie the clay-bearing unit may also be related to aqueous processes. Our study also details the formation of an unaltered mafic-rich dark resistant unit likely of Amazonian age that caps the other units and possibly originated from volcanism. Oxia Planum shows evidence for intense erosion from morphology (inverted features) and crater statistics. Due to these erosional processes, two types of Noachian sedimentary rocks are currently exposed. We also expect rocks at the surface to have been exposed to cosmic bombardment only recently, minimizing organic matter damage

Un colloque cerisyen sur l’aménagement du territoire, mode d’emploi

Entre le 27 septembre et le 2 octobre 2006, une centaine de personnes se sont rendues à Cerisy-la-Salle, un village d’un millier d’habitants, situé en plein cœur du Cotentin, pour assister au colloque sur l’aménagement du territoire dont les présents actes sont directement issus… Un colloque de plus sur un thème archidébattu pourra se dire a priori le lecteur, tant il est vrai que sont nombreuses les manifestations (séminaires, conférences, universités d’été…) consacrées à cet enjeu, en Franc..

Acclimatation dans le sud de la France d'Otiorhynchus (Dorymerus) armatus Boheman, 1843 (Coleoptera, Curculionidae)

Acclimatation in southern France of Otiorhynchus (Dorymerus) armatus (Boheman, 1843) (Coleoptera, Curculionidae). The weevil Otiorhynchus (Dorymerus) armatus (Boheman, 1843) is recorded for the first time from various localities in southern France. An addition to Hoffmann's keys allows to separate O. armatus (Boheman, 1843) from O. sulcatus (Fabricius, 1775) and O. corruptor (Host, 1789) a closely related species that also may be found in France.Le charançon Otiorhynchus (Dorymerus) armatus (Boheman, 1843) est signalé pour la première fois de diverses localités du sud de la France. Un complément des clés de Hoffmann permet de distinguer O. armatus (Boheman, 1843) d'O. sulcatus (Fabricius, 1775) ainsi que d'O. corruptor (Host, 1789), une espèce voisine qui pourrait aussi être rencontrée en France.Piry Sylvain, Gompel Nicolas, Allemand Roland. Acclimatation dans le sud de la France d'Otiorhynchus (Dorymerus) armatus Boheman, 1843 (Coleoptera, Curculionidae). In: Bulletin de la Société entomologique de France, volume 104 (5), décembre 1999. pp. 455-457

Réhabilitation de Athous puncticollis Kiesenwetter, 1858, espèce distincte de A. vittatus Fabricius, 1792

International audienceRehabilitation of Athous puncticollis Kiesenwetter, 1858, a species distinct from A. vittatus Fabricius, 1792 (Coleoptera, Elateridae). Athous puncticollis Kiesenwetter, 1858, considered as a synonym of Athous vittatus Fabricius, 1792, is removed from synonymy with this species. The molecular data presented here show that these two taxa are genetically distinct, and represent two mutually isolated species. Correlation between molecular and morphological data justifies the separation of these two species.Athous puncticollis Kiesenwetter, 1858, considéré comme synonyme de Athous vittatus Fabricius, 1792, est réhabilité comme espèce distincte. Les données moléculaires présentées ici indiquent que ces deux espèces sont génétiquement bien différenciées. La corrélation entre données moléculaires et morphologiques justifie pleinement leur séparation