Interactions of Deep-Sea Vent Invertebrates with Their Environment: The Case of Rimicaris exoculata

The vent shrimp Rimicaris exoculata thrives around many hydrothermal vent sites along the Mid-Atlantic Ridge (MAR), where it aggregates into dense swarms. In contrast to hydrothermal vent fields at the East Pacific Rise (EPR), where the biomass is dominated by tubeworms, clams, and mussels, this shrimp is one of the major animal species at MAR vents. These animals are found in the dynamic mixing interface between cold oxygenated seawater and hot, reduced hydrothermal vent fluid. The adaptation of this shrimp to the hostile deep-sea hydrothermal environment and its survival strategy has been investigated since their discovery at the TAG site in the late 1980s. Rimicaris exoculata is now known to colonize black smoker complexes along the MAR in the depth-range of 2,300-3,900 in (Rainbow, Broken Spur, TAG, Snake Pit, Logatchev, 5 degrees S (Rimicaris of exoculata). Although the presence of the Rimicaris genus was first believed to be restricted to the MAR, a related species, Rimicaris kairei, was found recently at the Central Indian Ridge (CIA) (Edmonds and Kairei vent field). This review summarizes the current knowledge of Rimicaris shrimp, focusing on their spatial and temporal distribution, chemical and thermal environment, as well as on possible nutrition strategies and behavioral aspects. Recent studies suggested that iron oxide encrusted bacteria hosted in the branchial chamber of R. exoculata from the Rainbow vent field (MAR) might rely on iron oxidation. Striking results on the occurrence and morphology of iron precipitates, as well as on bacterial-mineral interaction in the gill chamber, have lead to the hypothesis of an iron-based symbiosis between bacteria and the shrimp. Special attention is called to these issues

Tomography of bacteria–mineral associations within the deep-sea hydrothermal vent shrimp <i>Rimicaris exoculata</i>

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Insights into metazoan evolution from Alvinella pompejana cDNAs.

International audienceBACKGROUND: Alvinella pompejana is a representative of Annelids, a key phylum for evo-devo studies that is still poorly studied at the sequence level. A. pompejana inhabits deep-sea hydrothermal vents and is currently known as one of the most thermotolerant Eukaryotes in marine environments, withstanding the largest known chemical and thermal ranges (from 5 to 105°C). This tube-dwelling worm forms dense colonies on the surface of hydrothermal chimneys and can withstand long periods of hypo/anoxia and long phases of exposure to hydrogen sulphides. A. pompejana specifically inhabits chimney walls of hydrothermal vents on the East Pacific Rise. To survive, Alvinella has developed numerous adaptations at the physiological and molecular levels, such as an increase in the thermostability of proteins and protein complexes. It represents an outstanding model organism for studying adaptation to harsh physicochemical conditions and for isolating stable macromolecules resistant to high temperatures. RESULTS: We have constructed four full length enriched cDNA libraries to investigate the biology and evolution of this intriguing animal. Analysis of more than 75,000 high quality reads led to the identification of 15,858 transcripts and 9,221 putative protein sequences. Our annotation reveals a good coverage of most animal pathways and networks with a prevalence of transcripts involved in oxidative stress resistance, detoxification, anti-bacterial defence, and heat shock protection. Alvinella proteins seem to show a slow evolutionary rate and a higher similarity with proteins from Vertebrates compared to proteins from Arthropods or Nematodes. Their composition shows enrichment in positively charged amino acids that might contribute to their thermostability. The gene content of Alvinella reveals that an important pool of genes previously considered to be specific to Deuterostomes were in fact already present in the last common ancestor of the Bilaterian animals, but have been secondarily lost in model invertebrates. This pool is enriched in glycoproteins that play a key role in intercellular communication, hormonal regulation and immunity. CONCLUSIONS: Our study starts to unravel the gene content and sequence evolution of a deep-sea annelid, revealing key features in eukaryote adaptation to extreme environmental conditions and highlighting the proximity of Annelids and Vertebrates

Avant-propos : le développement durable au CNRS

Les dénominations institutionnelles sont l’expression des enjeux sous-jacents à leur attribution. En mai 2005, le Conseil d’administration du Centre national de la recherche scientifique approuvait la nouvelle architecture de l’organisme. Celle-ci comportait la création de six départements scientifiques, dont deux transverses, celui d’Ingénierie et celui intitulé « Environnement et Développement Durable », alors que les autres départements étaient regroupés autour des principales disciplines...

Vous avez dit « bébé éprouvette » ?

Gaill Françoise. Vous avez dit « bébé éprouvette » ?. In: Revue d'en face, n°13, 1983. Les femmes et la science. pp. 5-18

Processus biogéochimiques associés aux crevettes symbiotiques en environnement hydrothermal profond

La crevette R. exoculata domine la faune de sources hydrothermales de la ride médio-atlantique. La présence d oxyhydroxides de fer autour de bactéries localisées dans sa chambre branchiale a permis de proposer l hypothèse d une symbiose basée sur le métabolisme du fer. Une telle symbiose serait originale puisque les seules décrites jusqu à présent dépendaient de l oxydation des sulfures ou du méthane. Ce travail repose sur une approche multidisciplinaire qui définit les conditions thermiques et chimiques de l habitat de la crevette et le rôle joué par ces animaux dans le cycle biogéochimique du fer. La mise au point d un modèle biogéochimique montre que l oxydation du fer constitue une source d énergie majeure pour la croissance chimiolithoautotrophique sur le site riche en fer de Rainbow. Une étude cinétique a montré que les oxyhydroxydes ont pour origine la combinaison d oxydation du fer biotiques et abiotiques du fer. Il est suggéré que l oxydation du fer est initiée par les bactériesPARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Le chasseur et la nourrice

Frougny Christiane, Gaill Françoise. Le chasseur et la nourrice. In: Raison présente, n°57, 1er trimestre 1981. Le matin des biologistes ? pp. 91-98

DONNEES SUR LES INTERACTIONS BIOGEOCHIMIQUES EN MILIEU HYDROTHERMAL (L'EXEMPLE D'ALVINELLA POMPEJANA (DOCTORAT : PHYSIOLOGIE))

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF