Phylogeny and diversity of symbionts from whale fall invertebrates

Whale falls form oases at the bottom of the ocean that provide an energy source for a diverse and abundant fauna, including a new symbiosis type between Osedax worms and heterotrophic bacteria. Osedax infiltrate whale bones with their root tissues. These roots are filled with bacteria hypothesized to provide their hosts with nutrition by extracting organic compounds from the whale bones. This thesis is made of three thematic parts. The first part is a review on the ecology and evolution of Siboglinidae. The second part focuses on the diversity of the symbionts associated with Osedax mucofloris, where a higher diversity of Oceanospirillales bacteria was identified with eight monophyletic clusters. The symbiont clusters were not uniformly distributed, but one cluster dominated the population and each individual. In addition, when several clusters co-occurred in one individual they were not mixed but spatially separated. Statistical analyses showed that each O. mucofloris individual has a significant effect on symbionts diversity and distribution. Thus, each O. mucofloris individual has its own specific endosymbiont community. Our results suggest a horizontal transmission of the symbionts. Several scenarios explaining the observed symbionts distribution are considered including selection by the host, variability of the available symbionts, and competition between the symbionts. The third part of this thesis focuses on the symbionts of a polycheate worm, a Ctenodrilidae, Raricirrus beryli. Among the epibacteria, bacteria forming a monophyletic cluster with thiotrophic symbionts of bathymodiolin mussels were found. This is the first report of a polychaete host for these bacteria

ECMO for COVID-19 patients in Europe and Israel

Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

Philogenie und Diversität von Symbionten von Invertebraten, die auf Walskeletten leben

Whale falls form oases at the bottom of the ocean that provide an energy source for a diverse and abundant fauna, including a new symbiosis type between Osedax worms and heterotrophic bacteria. Osedax infiltrate whale bones with their root tissues. These roots are filled with bacteria hypothesized to provide their hosts with nutrition by extracting organic compounds from the whale bones. This thesis is made of three thematic parts. The first part is a review on the ecology and evolution of Siboglinidae. The second part focuses on the diversity of the symbionts associated with Osedax mucofloris, where a higher diversity of Oceanospirillales bacteria was identified with eight monophyletic clusters. The symbiont clusters were not uniformly distributed, but one cluster dominated the population and each individual. In addition, when several clusters co-occurred in one individual they were not mixed but spatially separated. Statistical analyses showed that each O. mucofloris individual has a significant effect on symbionts diversity and distribution. Thus, each O. mucofloris individual has its own specific endosymbiont community. Our results suggest a horizontal transmission of the symbionts. Several scenarios explaining the observed symbionts distribution are considered including selection by the host, variability of the available symbionts, and competition between the symbionts. The third part of this thesis focuses on the symbionts of a polycheate worm, a Ctenodrilidae, Raricirrus beryli. Among the epibacteria, bacteria forming a monophyletic cluster with thiotrophic symbionts of bathymodiolin mussels were found. This is the first report of a polychaete host for these bacteria

Phylogénie et diversité des symbionts d'invertébrés des chutes de carcasses de baleines

Après leur mort, l ultime chute des baleines sur les fonds océaniques, crée des oasis éphémères. Ces carcasses attirent une faune diversifiée et abondante dont un nouveau type de symbiose entre des bactéries hétérotrophes et le siboglinidé Osedax. Les Osedax sont des annélides dont la partie postérieure prend la forme d un tissu ramifié infiltrant les os. Les symbiontes y sont présents et aident potentiellement leur hôte dans la dégradation de molécules complexes présentes dans les os. Cette thèse comprend trois parties. La première partie est une synthèse sur l écologie et l évolution des Siboglinidae. La seconde partie présente les symbiontes d Osedax mucofloris qui sont encore plus diversifiés que ceux des autres Osedax, avec la présence de huit clades distincts de symbiontes. Un de ces clades domine la communauté bactérienne associée à O. mucofloris, et un clade seulement domine au sein de chaque individu. Lorsqu ils coexistent, les clades de symbiontes sont spatialement restreints dans des zones différentes du tissu ramifié. Des analyses statistiques multivariées montrent que la population des symbiontes est significativement structurée au niveau de chaque individu, qui a donc sa propre population de symbiontes. De plus, cette étude suggère que l acquisition des symbiontes est environnementale. La troisième partie décrit les bactéries associées à un autre polychète de la famille Ctenodrilidae, Raricirrus beryli. Parmi les bactéries présentes sur la surface du ver, certaines forment un groupe monophylétique avec des symbiontes de moules de la sous-famille Bathymodiolinae. Cette étude est la première à montrer que ces bactéries peuvent s associer avec un polychète.PARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceGermanyFRD

The Skeletal Remains of Soldiers from the Two World Wars: between Identification, Health Research and Memorial Issues

International audienceAfter causing mass disasters that claimed the lives of tens of thousands of soldiers from countries around the world, the two Great Wars left some of them lost and missing. In France, these corpses reside in a legal vagueness where they belong neither to forensic anthropology nor archeology. Nevertheless, the process of identification and determining the cause of death requires the use of modern forensic anthropology by applying biological profiling and DNA analysis. New genomic methods also provide insight into the health statuses of these military populations, providing new perspectives on these periods of humanitarian crisis

Gestion of wars remains : Archaeo-anthropology of conflict in France

International audienceThe corpses of soldiers from the two world wars are a recurring issue, particularly regarding their management on French territory. Since French soldiers were awarded with the "Dead for France" mention, their remains have been the responsibility of the Ministry of the Armed Forces, which excludes archaeological and forensic management. The discipline of forensic archaeology, well known in Europe, is rarely, if ever, used in France. As a result, soldiers' finds are part of a new type of management linked to contemporary armed conflicts, directly attached to the Ministry of the Armed Forces (since the Franco-Prussian War of 1870). This poster shows how these remains are handled, from excavation to burial in the national necropolis or family vault. Artefacts, biological information, and archival context are valuable materials for understanding these contexts. For some of the deceased, identity is still accessible, and biological anthropology methods are essential to make the best use of the information available. DNA and genealogical studies are also part of the research process, pushing back the limits of possible identification in such contexts. Our work is an example of interdisciplinarity in this field of research, and of how we can open the doors to the duty of remembrance of a not-so-distant past

Data from: Cryptic habitats and cryptic diversity: unexpected patterns of connectivity and phylogeographic breaks in a Mediterranean endemic marine cave mysid

The marine cave-dwelling mysid Hemimysis margalefi is distributed over the whole Mediterranean Sea which contrasts with the poor dispersal capabilities of this brooding species. In addition, underwater marine caves are a highly fragmented habitat which further promotes strong genetic structuring, therefore providing highly informative data on the levels of marine population connectivity across biogeographic regions. This study investigates how habitat and geography have shaped the connectivity network of this poor disperser over the entire Mediterranean Sea through the use of several mitochondrial and nuclear markers. Five deeply divergent lineages were observed among H. margalefi populations resulting from deep phylogeographic breaks, some dating back to the Oligo-Miocene. Whether looking at the intra-lineage or inter-lineage levels, H. margalefi populations present a high genetic diversity and population structuring. This study suggests that the five distinct lineages observed in H. margalefi actually correspond to as many separate cryptic taxa. The nominal species, H. margalefi sensu stricto, corresponds to the westernmost lineage here surveyed from the Alboran Sea to south-eastern Italy. Typical genetic breaks such as the Almeria-Oran Front or the Sicilo-Tunisian Strait do not appear to be influential on the studied loci in H. margalefi sensu stricto. Instead, population structuring appears more complex and subtle than usually found for model species with a pelagic dispersal phase. The remaining four cryptic taxa are all found in the eastern basin, but incomplete lineage sorting is suspected and speciation might still be in process. Present day population structure of the different H. margalefi cryptic species appears to result from past vicariance events started in the Oligo-Miocene and maintained by present day coastal topography, water circulation and habitat fragmentation