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101.
Oxidation of unsaturated lipids is a fundamental process involved in cell bioenergetics as well as in cell death. Using giant unilamellar vesicles and a chlorin photosensitizer, we asymmetrically oxidized the outer or inner monolayers of lipid membranes. We observed different shape transitions such as oblate to prolate and budding, which are typical of membrane curvature modifications. The asymmetry of the shape transitions is in accordance with a lowered effective spontaneous curvature of the leaflet being targeted. We interpret this effect as a decrease in the preferred area of the targeted leaflet compared to the other, due to the secondary products of oxidation (cleaved-lipids). Permeabilization of giant vesicles by light-induced oxidation is observed after a lag and is characterized in relation with the photosensitizer concentration. We interpret permeabilization as the opening of a pore above a critical membrane tension, resulting from the budding of vesicles. The evolution of photosensitized giant vesicle lysis tension was measured and yields an estimation of the effective spontaneous curvature at lysis. Additionally photo-oxidation was shown to be fusogenic. 相似文献
102.
Manon Quiquand Jürgen Schmich Brigitte Galliot Stefano Piraino 《Developmental biology》2009,328(2):173-187
Hox and ParaHox (H/P) genes belong to evolutionary-sister clusters that arose through duplication of a ProtoHOX cluster early in animal evolution. In contrast to bilaterians, cnidarians express, beside PG1, PG2 and Gsx orthologs, numerous Hox-related genes with unclear origin. We characterized from marine hydrozoans three novel Hox-related genes expressed at medusa and polyp stages, which include a Pdx/Xlox ParaHox ortholog induced 1 day later than Gsx during embryonic development. To reconstruct H/P genes' early evolution, we performed multiple systematic comparative phylogenetic analyses, which identified derived sequences that blur the phylogenetic picture, recorded dramatically different evolutionary rates between ParaHox and Hox in cnidarians and showed the unexpected grouping of [Gsx-Pdx/Xlox-PG2-PG3] families in a single metagroup distinct from PG1. We propose a novel more parsimonious evolutionary scenario whereby H/P genes originated from a [Gsx-Pdx/Xlox-PG2-PG3]-related ProtoHox gene, the «posterior» and «anterior» H/P genes appearing secondarily. The ProtoHOX cluster would have contained the three Gsx/PG2, Pdx/PG3, Cdx/PG9 paralogs and produced through tandem duplication the primordial HOX and ParaHOX clusters in the Cnidaria-Bilateria ancestor. The stronger constraint on cnidarian ParaHox genes suggests that the primary function of pre-bilaterian H/P genes was to drive cellular evolutionary novelties such as neurogenesis rather than axis specification. 相似文献
103.
Practice on castration of piglets in Europe 总被引:1,自引:0,他引:1
Fredriksen B Font I Furnols M Lundström K Migdal W Prunier A Tuyttens FA Bonneau M 《Animal : an international journal of animal bioscience》2009,3(11):1480-1487
PIGCAS (Attitudes, practices and state of the art regarding piglet castration in Europe) is to our knowledge the first project that has focused on castration practice across European countries (European Union minus Bulgaria, Malta and Romania, plus Norway and Switzerland). About 250 million pigs are slaughtered in Europe each year. Of the 125 million male pigs, approximately 20% are left entire, less than 3% are castrated with anaesthesia and the rest is castrated without anaesthesia. The study identified large variations in castration procedures, both within and between countries. In females, castration is very rare, but is practiced without anaesthesia in special breeds/production systems in some of the southern countries. 相似文献
104.
Sari Neijenhuis Manon Verwijs-Janssen Ulla Kasten-Pisula Gaby Rumping Kerstin Borgmann Ekkehard Dikomey Adrian C. Begg Conchita Vens 《DNA Repair》2009,8(3):336-346
Several types of DNA lesion are induced after ionizing irradiation (IR) of which double strand breaks (DSBs) are expected to be the most lethal, although single strand breaks (SSBs) and DNA base damages are quantitatively in the majority. Proteins of the base excision repair (BER) pathway repair these numerous lesions. DNA polymerase beta has been identified as a crucial enzyme in BER and SSB repair (SSBR). We showed previously that inhibition of BER/SSBR by expressing a dominant negative DNA polymerase beta (polβDN) resulted in radiosensitization. We hypothesized increased kill to result from DSBs arising from unrepaired SSBs and BER intermediates. We find here higher numbers of IR-induced chromosome aberrations in polβDN expressing cells, confirming increased DSB formation. These aberrations did not result from changes in DSB induction or repair of the majority of lesions. SSB conversion to DSBs has been shown to occur during replication. We observed an increased induction of chromatid aberrations in polβDN expressing cells after IR, suggesting such a replication-dependence of secondary DSB formation. We also observed a pronounced increase of chromosomal deletions, the most likely cause of the increased kill. After H2O2 treatment, polβDN expression only resulted in increased chromatid (not chromosome) aberrations. Together with the lack of sensitization to H2O2, these data further suggest that the additional secondarily induced lethal DSBs resulted from repair attempts at complex clustered damage sites, unique to IR. Surprisingly, the polβDN induced increase in residual γH2AX foci number was unexpectedly low compared with the radiosensitization or induction of aberrations. Our data thus demonstrate the formation of secondary DSBs that are reflected by increased kill but not by residual γH2AX foci, indicating an escape from γH2AX-mediated DSB repair. In addition, we show that in the polβDN expressing cells secondary DSBs arise in a radiation-specific and partly replication-dependent manner. 相似文献
105.
Marie-Laure Fardeau Vanessa Barsotti Jean-Luc Cayol Sophie Guasco Valérie Michotey Manon Joseph Patricia Bonin Bernard Ollivier 《Extremophiles : life under extreme conditions》2010,14(3):241-247
A novel facultative microaerophilic nitrate-reducing bacterium designated CA62NT was isolated from a thermal spring in France. Cells were non-motile rods (2–3 × 0.2 μm) and showed low cytoplasmic density
when observed under a phase-contrast microscope. Strain CA62NT grew at temperatures between 50 and 75°C (optimum 65°C) and at a pH between 6.3 and 7.9 (optimum 7.0). NaCl was not required
for growth but was tolerated up to 10 gl−1. Sulfate, thiosulfate, elemental sulfur, sulfite, and nitrite were not used as electron acceptors. Nitrate was reduced to
nitrite. Strain CA62NT used lactate, pyruvate, glucose, mannose, fructose, and casamino acids and some amino acids as electron donors only in the
presence of nitrate as electron acceptor. None of these substrates was fermented. The main end-products of glucose oxidation
were acetate, CO2, and traces of H2. The G + C content of the genomic DNA was 70.3 mol% (HPLC techniques). Phylogenetic analysis of the small-subunit (SSU) ribosomal
RNA (rRNA) gene sequence indicated that strain CA62NT was affiliated to the Symbiobacterium branch within the Firmicutes and had Symbiobacterium thermophilum and “S. toebii” as its closest phylogenetic relatives. On the basis of phylogenetical and physiological characteristics, strain CA62NT is proposed to be the type strain for the novel species in the novel genus, Caldinitratiruptor microaerophilus gen. nov., sp. nov. (DSM 22660, JCM 16183). 相似文献
106.
Didier Alazard Manon Joseph Fabienne Battaglia-Brunet Jean-Luc Cayol Bernard Ollivier 《Extremophiles : life under extreme conditions》2010,14(3):305-312
An obligately anaerobic, spore-forming, acidophilic sulfate-reducing bacterium, strain SJ4T, was isolated from an acid mining effluent decantation pond sediment sample (pH around 3.0). Cells were Gram negative, non-motile,
curved rods occurring singly. Strain SJ4T grew at pH 3.6–5.5 with an optimum at pH 5.2. Strain SJ4T utilized H2, lactate, pyruvate, glycerol, glucose, and fructose as electron donors. Lactate and glucose were weakly used. Sulfate was
used as electron acceptors, but not sulfite, elemental sulfur, arsenate (V), and fumarate. The G + C content of genomic DNA
was 42.3 mol% (HPLC). 16S rRNA gene sequence analysis indicated that strain SJ4T belonged to the genus Desulfosporosinus within the family Peptococcaceae in the phylum Firmicutes. The level of 16S rRNA gene sequence similarity with other Desulfosporosinus species was 94.7–96.2%, D. orientis DSM 765T (similarity of 96.2%) and D. auripigmenti DSM 13351T (similarity of 95%) being its closest relatives. DNA–DNA relatedness values with D. orientis and D. auripigmenti were 16.5 and 31.8%, respectively. On the basis of phenotypic, phylogenetic, and genetic characteristics, strain SJ4T represents a novel species within the genus Desulfosporosinus, for which the name Desulfosporosinus acidiphilus sp. nov. is proposed. The type strain is SJ4T (=DSM 22704T = JCM 16185T). 相似文献
107.
Waltman P Kacmarczyk T Bate AR Kearns DB Reiss DJ Eichenberger P Bonneau R 《Genome biology》2010,11(9):R96
We describe an algorithm, multi-species cMonkey, for the simultaneous biclustering of heterogeneous multiple-species data
collections and apply the algorithm to a group of bacteria containing Bacillus subtilis, Bacillus anthracis, and Listeria monocytogenes. The algorithm reveals evolutionary insights into the surprisingly high degree of conservation of regulatory modules across
these three species and allows data and insights from well-studied organisms to complement the analysis of related but less
well studied organisms. 相似文献
108.
Spleen-dependent turnover of CD11b peripheral blood B lymphocytes in bovine leukemia virus-infected sheep
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Florins A Gillet N Asquith B Debacq C Jean G Schwartz-Cornil I Bonneau M Burny A Reichert M Kettmann R Willems L 《Journal of virology》2006,80(24):11998-12008
Lymphocyte homeostasis is determined by a critical balance between cell proliferation and death, an equilibrium which is deregulated in bovine leukemia virus (BLV)-infected sheep. We have previously shown that an excess of proliferation occurs in lymphoid tissues and that the peripheral blood population is prone to increased cell death. To further understand the mechanisms involved, we evaluated the physiological role of the spleen in this accelerated turnover. To this end, B lymphocytes were labeled in vivo using a fluorescent marker (carboxyfluorescein diacetate succinimidyl ester), and the cell kinetic parameters (proliferation and death rates) of animals before and after splenectomy were compared. We show that the enhanced cell death observed in BLV-infected sheep is abrogated after splenectomy, revealing a key role of the spleen in B-lymphocyte dynamics. 相似文献
109.
110.
Manon M. S. Richard Stéphanie Pflieger Mireille Sévignac Vincent Thareau Sophie Blanchet Yupeng Li Scott A. Jackson Valérie Geffroy 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(7):1653-1666