Éditeur(s) : HAL CCSD American Chemical Society
Résumé : International audience
The present study is a contribution to the "neXt50 challenge", a coordinated effort across C-HPP teams to identify the SO most tractable missing proteins (MPs) on each chromosome. We report the targeted search of 38 theoretically detectable MPs from chromosomes 2 and 14 in Triton X-100 soluble and insoluble sperm fractions from a total of 15 healthy donors. A targeted mass spectrometry-based strategy consisting of the development of LC-PRM assays (with heavy labeled synthetic peptides) targeting 92 proteotypic peptides of the 38 selected MPs was used. Out of the 38 selected MPs, 12 were identified with two or more peptides and 3 with one peptide after extensive SDS-PAGE fractionation of the two samples and with overall low-intensity signals. The PRM data are available via ProteomeXchange in PASSEL (PASS01013). Further validation by immunohistochemistry on human testes sections and cytochemistry on sperm smears was performed for eight MPs with antibodies available from the Human Protein Atlas. Deep analysis of human sperm still allows the validation of MPs and therefore contributes to the C-HPP worldwide effort. We anticipate that our results will be of interest to the reproductive biology community because an in-depth analysis of these MPs may identify potential new candidates in the context of human idiopathic infertilities.
ISSN: 1535-3893

hal-01681656
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01681656
DOI : 10.1021/acs.jproteome.7b00374

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
North Tanzanian Divergence is the first stage of continental break-up of East African Rift (<6 Ma) and is one of the most concentrated areas of carbonatite magmatism on Earth, with singular Oldoinyo Lengai and Kerimasi volcanoes. Hanang volcano is the southernmost volcano in the North Tanzanian Divergence and the earliest stage of rift initiation. Hanang volcano erupted silica-undersaturated alkaline lavas with zoned clinopyroxene, nepheline, andradite-schorlomite, titanite, apatite, and pyrrhotite. Lavas are low MgO-nephelinite with low Mg# and high silica content (Mg# = 22.4–35.2, SiO2 = 44.2–46.7 wt%, respectively), high incompatible element concentrations (e.g. REE, Ba, Sr) and display Nb–Ta fractionation (Nb/Ta = 36–61). Major elements of whole rock are consistent with magmatic differentiation by fractional crystallization from a parental melt with melilititic composition. Although fractional crystallization occurred at 9–12 km and can be considered as an important process leading to nephelinite magma, the complex zonation of cpx (e.g. abrupt change of Mg#, Nb/Ta, and H2O) and trace element patterns of nephelinites recorded magmatic differentiation involving open system with carbonate–silicate immiscibility and primary melilititic melt replenishment. The low water content of clinopyroxene (3–25 ppm wt. H2O) indicates that at least 0.3 wt% H2O was present at depth during carbonate-rich nephelinite crystallization at 340–640 MPa and 1050–1100 °C. Mg-poor nephelinites from Hanang represent an early stage of the evolution path towards carbonatitic magmatism as observed in Oldoinyo Lengai. Paragenesis and geochemistry of Hanang nephelinites require the presence of CO2-rich melilititic liquid in the southern part of North Tanzanian Divergence and carbonate-rich melt percolations after deep partial melting of CO2-rich oxidized mantle source.
ISSN: 0010-7999

hal-01467390
https://hal.archives-ouvertes.fr/hal-01467390
DOI : 10.1007/s00410-016-1273-5

Éditeur(s) : HAL CCSD
Résumé : In Suriname, Saramaka (descendants from fugitives slaves of the XVIIth century) still have a widely used traditional pharmacopoeia. The Bitter-cup is a good example because of the place it keeps on the Paramaribo's markets stands. We conducted an ethnopharmacological study in order to detail its uses: rum or water left to macerate in the cup overnight, the content is drunk straight in the morning either as a tonic, stomachic, febrifuge or antimalarial remedy. In order to close the controversy about its botanical origin, we proceeded to an anatomical study of woods and cups found at the market. Chemicals fingerprints by High Performance Liquid Chromatography (HPLC) were simultaneously established. The two methods, complementary, allowed us to identify Quassia amara L. as cups source. In vitro assays of the macerates on Plasmodium falciparum did not show any antimalarial activity, while some fractions, obtained by semi-preparative HPLC, did show a high activity against parasites.
Les Saramaka du Suriname, descendants d'esclaves échappés des plantations au XVIIème siècle, ont une pharmacopée traditionnelle encore vive. Le Bitter-cup, ou " gobelet amer ", en est un exemple puisqu'il garde encore sa place sur les étals des marchés de Paramaribo. Nous avons mené une enquête ethnopharmacologique afin de détailler ses usages : mis à macérer pendant une nuit avec du rhum ou de l'eau, le contenu est bu d'un trait au matin comme tonique amer, stomachique, fébrifuge ou encore antimalarique. Pour mettre fin aux controverses que suscite sa provenance botanique, nous avons procédé à une étude anatomique du bois et des gobelets provenant du marché, ainsi qu'à l'établissement de signatures chimiques par Chromatographie Liquide Haute Performance (CLHP). Ces deux méthodes complémentaires nous ont permis d'identifier Quassia amara L. comme source des gobelets. Des tests in vitro sur Plasmodium falciparum n'ont pas confirmé l'activité antipaludique, mais après un fractionnement bioguidé par CLHP semi-préparative, certaines fractions se montrent très performantes contre les parasites.
https://tel.archives-ouvertes.fr/tel-00636165

tel-00636165
https://tel.archives-ouvertes.fr/tel-00636165
https://tel.archives-ouvertes.fr/tel-00636165/document
https://tel.archives-ouvertes.fr/tel-00636165/file/thesePharma_Odonne.PDF

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
We investigated the characteristics of the sulfur-oxidizing symbiont hosted in the gills of Codakia orbicularis, a bivalve living in shallow marine tropical environments. Special attention was paid to describing the heterogeneity of the population by using single-cell approaches including flow cytometry (FCM) and different microscopic techniques and by analyzing a cell size fractionation experiment. Up to seven different subpopulations were distinguished by FCM based on nucleic acid content and light side scattering of the cells. The cell size analysis of symbionts showed that the symbiotic population was very heterogeneous in size, i.e., ranging from 0.5 to 5 _m in length, with variable amounts of intracellular sulfur. The side-scatter signal analyzed by FCM, which is often taken as a proxy of cell size, was greatly influenced by the sulfur content of the symbionts. FCM revealed an important heterogeneity in the relative nucleic acid content among the subclasses. The larger cells contained exceptionally high levels of nucleic acids, suggesting that these cells contained multiple copies of their genome, i.e., ranging from one copy for the smaller cells to more than four copies for the larger cells. The proportion of respiring symbionts (5-cyano-2,3-ditolyl-terazolium chloride positive) in the bacteriocytes of Codakia revealed that around 80% of the symbionts hosted by Codakia maintain respiratory activity throughout the year. These data allowed us to gain insight into the functioning of the symbionts within the host and to propose some hypotheses on how the growth of the symbionts is controlled by the host.
ISSN: 0099-2240

hal-00716079
https://hal.univ-antilles.fr/hal-00716079
DOI : 10.1128/AEM.01683-06

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The outer membrane proteins (OMPs) of Gram-negative bacteria play a crucial role in virulence and pathogenesis. Identification of these proteins represents an important goal for bacterial proteomics, because it aids in vaccine development. Here, we have developed such an approach for Ehrlichia ruminantium, the obligate intracellular bacterium that causes heartwater. A preliminary whole proteome analysis of elementary bodies, the extracellular infectious form of the bacterium, had been performed previously, but information is limited about OMPs in this organism and about their role in the protective immune response. Identification of OMPs is also essential for understanding Ehrlichia’s OM architecture, and how the bacterium interacts with the host cell environment. First, we developed an OMP extraction method using the ionic detergent sarkosyl, which enriched the OM fraction. Second, proteins were separated via one-dimensional electrophoresis, and digested peptides were analyzed via nano-liquid chromatographic separation coupled with mass spectrometry (LCMALDI-TOF/TOF). Of 46 unique proteins identified in the OM fraction, 18 (39%) were OMPs, including 8 proteins involved in cell structure and biogenesis, 4 in transport/virulence, 1 porin, and 5 proteins of unknown function. These experimental data were compared to the predicted subcellular localization of the entire E. ruminantium proteome, using three different algorithms. This work represents the most complete proteome characterization of the OM fraction in Ehrlichia spp. The study indicates that suitable subcellular fractionation experiments combined with straightforward computational analysis approaches are powerful for determining the predominant subcellular localization of the experimentally observed proteins.We identified proteins potentially involved in E. ruminantium athogenesis, which are good novel targets for candidate vaccines. Thus, combining bioinformatics and proteomics, we discovered new OMPs for E. ruminantium that are valuable data for those investigating new vaccines against this organism. In summary, we provide both pioneering data and novel insights into the pathogenesis of this obligate intracellular bacterium.
ISSN: 1932-6203

hal-01203402
https://hal.univ-antilles.fr/hal-01203402
https://hal.univ-antilles.fr/hal-01203402/document
https://hal.univ-antilles.fr/hal-01203402/file/2015_Moumene_PLOSONE-1.pdf
DOI : 10.1371/journal.pone.0116758

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Geochemical studies of primitive basalts have documented the presence of crustal-derived garnet pyroxenite in their mantle sources. The processes whereby melts with the signature of garnet pyroxenite are produced in the mantle are, however, poorly understood and somewhat controversial. Here we investigate a natural example of the interaction between melts of garnet pyroxenite derived from recycled plagioclase-rich crust and surrounding mantle in the Ronda peridotite massif. Melting of garnet pyroxenite at ∼1.5 GPa generated spinel websterite residues with MREE/HREE fractionation and preserved the positive Eu anomaly of their garnet pyroxenite precursor in whole-rock and clinopyroxene. Reaction of melts from garnet pyroxenite with depleted surrounding peridotite generated secondary fertile spinel lherzolite. These secondary lherzolites differ from common spinel lherzolite from Ronda and elsewhere by their lower-Mg# in clinopyroxene, orthopyroxene and olivine, lower-Cr# in spinel and higher whole-rock Al2O3, CaO, Sm/Yb and FeO⁎ at a given SiO2. Remarkably, secondary spinel lherzolite shows the geochemical signature of ghost plagioclase in the form of positive Eu and Sr anomalies in whole-rock and clinopyroxene, reflecting the transfer of a low-pressure crustal imprint from recycled pyroxenite to hybridized peridotite. Garnet pyroxenite melting and melt-peridotite interaction, as shown in the Ronda massif, may explain how the signature of subducted or delaminated crust is transferred to the mantle and how a garnet pyroxenite component is introduced into the source region of basalts. The efficiency of these processes in conveying the geochemical imprint of crustal-derived garnet pyroxenite to extruded lavas depends on the reactivity of pyroxenite melt with peridotite and the mantle permeability, which may be controlled by prior refertilization reactions similar to those documented in the Ronda massif. Highly fertile heterogeneities produced by pyroxenite-peridotite interaction, such as secondary spinel lherzolite in Ronda, may nucleate magmatic channels that remain chemically isolated from the ambient mantle and act as preferential pathways for melts with the signature of recycled crust.
ISSN: 0012-821X

hal-00814010
https://hal.archives-ouvertes.fr/hal-00814010
DOI : 10.1016/j.epsl.2012.11.047

Éditeur(s) : HAL CCSD
Résumé : Carbon isotopic signature has been measured at the different stages of the soil CO2 efflux production in trenched and control plots to improve the knowledge about the physical and biochemical processes of the soil respiration. All the measurements of _13C have been performed using a mass-spectrometer.We have compared the isotopic signatures of the CO2 going out of the soil, the CO2 of the soil atmosphere, the organic carbon in the material that could be considered as the main soil respiration sources (live and dead roots, soil organic matter, aerial litter) and the CO2 produced by these sources in incubation jars. The aims of this study were to evaluate the possibilities to combine these different data sets to estimate the partitioning of soil respiration between its autotrophic and heterotrophic components, and to get more insight into potential fractionation during biochemical or diffusion processes. Measurements were conducted in a beech forest located at Hesse in the North East of France (site equipped with a flux tower and belonging to the CarboEurope network) and in a neotropical primary rainforest located at Paracou (French Guiana). Preliminary results show first a very tenuous difference between CO2 isotopic signatures of efflux coming from the trenched and control plots and, secondly, _13C significant divergences between bulk organic material and CO2 produced in the corresponding incubation jars. Our ability to use this kind of data for partitioning soil respiration into its main components will be discussed.
Geophysical Research Abstracts

hal-01031785
https://hal.archives-ouvertes.fr/hal-01031785

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Several recent studies have documented that reactions between melt and crystal mush in primitive gabbroic rocks (via reactive porous flow) have an important control in the formation of the lower oceanic crust and the evolution of MORBs. In this context, olivine-rich rocks can form either by fractional crystallization of primitive melts or by open system reactive percolation of pre-existing (possibly mantle-derived) olivine matrix. To address this question, we performed in-situ trace element analyses (by LA-ICP-MS) of olivine from the Erro-Tobbio ophiolite Unit (Ligurian Alps), where mantle peridotites show gradational contacts with an hectometer-scale body of troctolites and plagioclase wehrlites, and both are cut by later decameter-wide lenses and dykes of olivine gabbros. Previous studies inferred that troctolites and olivine gabbros represent variably differentiated crystallization products from primitive MORB-type melts. Olivines in the three rock types (mantle peridotites, troctolites, olivine gabbros) exhibit distinct geochemical signature and well-defined elemental correlations. As expected, compatible elements (e.g. Ni) show the highest concentrations in peridotites (2580–2730 ppm), intermediate in troctolites (2050–2230 ppm) and lowest in gabbros (1355–1420 ppm), whereas moderate incompatible elements (e.g. Mn, Zn) show the opposite behaviour. By contrast, highly incompatible elements like Zr, Hf, Ti, HREE are variably enriched in olivines of troctolites, and the enrichment in absolute concentrations is coupled to development of significant HFSE/REE fractionation (ZrN/NdN up to 80). AFC modelling shows that such large ZrN/NdN ratios in olivines are consistent with a process of olivine assimilation and plagioclase crystallization at decreasing melt mass, in agreement with textural observations. In-situ trace element geochemistry of olivine, combined with microstructural investigations, thus appears a powerful tool to investigate reactive percolation and the origin of olivine-rich rocks in the lower oceanic crust.
ISSN: 0016-7037

hal-01419938
https://hal.archives-ouvertes.fr/hal-01419938
DOI : 10.1016/j.gca.2016.06.029

Éditeur(s) : HAL CCSD Elsevier
Résumé : In situ analysis of major elements, platinum-group elements and Os isotope composition data for 170 grains of Ru–Os–Ir alloys from podiform chromitites in the Luobusa and Dongqiao ophiolites, Tibet, provide new constraints on the sources of the alloy grains, the Os-isotope composition of the Neo-Tethyan oceanic upper mantle, and the timing of melt–rock reactions in the ultramafic peridotites of the host ophiolites. Most alloy grains are osmiridium and iridosmine. Based on elemental and isotopic compositions, two populations can be identified. Group I, found in both ophiolite bodies, has fractionated PGE patterns typical of alloys and homogeneous 187Os/188Os 0.12645 ± 4 (2s; n = 145). Group II alloys from the Dongqiao ophiolites show smooth PGE patterns and 187Os/188Os ranges from 0.12003 to 0.12194 (yielding Re-depletion ages ≥ 1.1 Ga). Both the PGE patterns and the Os isotopic compositions of Group II resemble those of sulfides residual after melting. Group I alloys represent an early cumulate phase during the crystallization of magmas and are interpreted as derived from an asthenospheric melt. In contrast, Group II alloys are inferred to derive from the breakdown of residual sulfides from the mantle section of the ophiolite, which may represent relics of a sub-continental lithospheric mantle. The coexistence of the two groups of alloys in Dongqiao samples reflects interaction between asthenosphere-derived melts and old depleted lithospheric mantle and suggests that the chromitites originated through melt–rock reactions. The data on the Group I alloys support the hypothesis that the Re–Os evolution of the convective oceanic mantle resembles that of enstatite chondrites.
ISSN: 0012-821X

hal-00404967
https://hal.archives-ouvertes.fr/hal-00404967
DOI : 10.1016/j.epsl.2007.05.044

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
We report trace element analyses from mineral phases in chondrules from carbonaceous chondrites (Vigarano, Renazzo, and Acfer 187), carried out by laser ablation inductively coupled plasma-mass spectrometry. Results are similar in all three meteorites. Mesostasis has rare earth element (REE) concentrations of 10-20 × CI. Low-Ca pyroxene has light REE (LREE) concentrations near 0.1 × CI and heavy REE (HREE) near 1 × CI, respectively. Olivine has HREE concentrations at 0.1-1 × CI and LREE around 10−2 × CI. The coarsest olivine crystals tend to have the most fractionated REE patterns, indicative of equilibrium partitioning. Low-Ca pyroxene in the most pyroxene-rich chondrules tends to have the lowest REE concentrations. Type I chondrules seem to have undergone a significant degree of batch crystallization (as opposed to fractional crystallization), which requires cooling rates slower than 1-100 K h−1. This would fill the gap between igneous calcium-aluminum-rich inclusions (CAIs) and type II chondrules. The anticorrelation between REE abundances and pyroxene mode may be understood as due to dilution by addition of silica to the chondrule melt, as in the gas-melt interaction scenario of Libourel et al. (2006). The rapid cooling rate (of the order of 1000 K h−1) which seems recorded by low-Ca pyroxene, contrasted with the more diverse record of olivine, may point to a nonlinear cooling history or suggest that formation of pyroxene-rich chondrule margins was an event distinct from the crystallization of the interior.
ISSN: 1086-9379

hal-00795434
https://hal.archives-ouvertes.fr/hal-00795434
DOI : 10.1111/maps.12005