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61.
Eric Mandrou Marie Denis Christophe Plomion Franck Salin Frédéric Mortier Jean-Marc Gion 《Tree Genetics & Genomes》2014,10(5):1281-1290
Lignin is a major chemical compound of wood and one of the most abundant organic biopolymers on earth. It accumulates in the secondary cell wall of xylem cells and is a major target for tree breeders because of its foreseen role in the emerging bioeconomy. In this study, we paved the way toward an accelerated domestication of a widely grown tree species, Eucalyptus urophylla, by molecular breeding. To this end, we first described the pattern of nucleotide variation occurring at seven structural and regulatory genes of the lignin biosynthesis pathway and found high levels of average nucleotide and haplotype diversity per gene (π?=?0.0065 and Hd?=?0.853). Then, taking advantage of a pre-existing factorial mating design, a candidate-gene-based quantitative trait locus (QTL) detection strategy was used to compare the variation of lignin quality (syringyl by guaiacyl ratio (S/G)) with the nucleotidic variability in these seven genes in 304 genotypes belonging to 33 connected full-sib families. Two genes, encoding cinnamoyl-CoA reductase (CCR) and a Rho-like GTPase (ROP1), were shown to be linked to the variation of S/G through different single and multi-locus single-nucleotide polymorphism (SNP)- and haplotype-based association methods. Providing that relevant candidate genes are selected and their patterns of nucleotide diversity is accurately described, we showed that quantitative trait nucleotides (QTNs) can be detected taking advantage of pre-existing field experiments and trait measurements gathered in the framework of a forest tree breeding program. 相似文献
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63.
LAYLA SAAD GRÉGORY MAHY 《Botanical journal of the Linnean Society. Linnean Society of London》2009,159(1):123-135
Oncocyclus irises endemic to Lebanon form a complex of three closely related taxa replacing each other over short geographical distances in a linear habitat. In order to characterize the appropriate taxonomic levels and to assess their conservation status, we investigated patterns of phenotypic variability and the partitioning of genetic variation within and among populations using random amplified polymorphic DNA (RAPD) markers. Multivariate analysis (principal components analysis and multiple correspondence analysis), based on 16 quantitative and six qualitative characters, revealed no separation between populations or taxa. Moreover, no morphological character could be used to define clear boundaries between populations/taxa. The genetic characterization revealed high levels of polymorphism and diversity (Hs). Principal components analysis showed population delimitations, but no groupings reflecting the currently defined taxa could be identified. Both morphological and genetic data showed that Lebanese oncocyclus irises could not be fitted into clear taxonomic boundaries. Consequences for conservation are discussed. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 123–135. 相似文献
64.
Caroline Ballot Jérome Kluza Steve Lancel Alain Martoriati Sidi Mohamed Hassoun Laurent Mortier Jean-Claude Vienne Gilbert Briand Pierre Formstecher Christian Bailly Remi Nevière Philippe Marchetti 《Apoptosis : an international journal on programmed cell death》2010,15(7):769-781
Lamellarin D (Lam D), a marine alkaloid, exhibits a potent cytotoxicity against many different tumors. The pro-apoptotic function of Lam D has been attributed to its direct induction of mitochondrial permeability transition (MPT). This study was undertaken to explore the mechanisms through which Lam D promotes changes in mitochondrial function and as a result apoptosis. The use of eight Lam derivatives provides useful structure-apoptosis relationships. We demonstrate that Lam D and structural analogues induce apoptosis of cancer cells by acting directly on mitochondria inducing reduction of mitochondrial membrane potential, swelling and cytochrome c release. Cyclosporin A, a well-known inhibitor of MPT, completely prevents mitochondrial signs of apoptosis. The drug decreases calcium uptake by mitochondria but not by microsomes indicating that Lam D-dependent permeability is specific to mitochondrial membranes. In addition, upon Lam D exposure, a rapid decline of mitochondrial respiration and ATP synthesis occurs in isolated mitochondria as well as in intact cells. Evaluation of the site of action of Lam D on the electron-transport chain revealed that the activity of respiratory chain complex III is reduced by a half. To determine whether Lam D could induce MPT-dependent apoptosis by inhibiting mitochondrial respiration, we generated respiration-deficient cells (ρ0) derived from human melanoma cells. In comparison to parental cells, ρ0 cells are totally resistant to the induction of MPT-dependent apoptosis by Lam D. Our results indicate that functional mitochondria are required for Lam D-induced apoptosis. Inhibition of mitochondrial respiration is responsible for MPT-dependent apoptosis of cancer cells induced by Lam-D. 相似文献
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66.
Sylvie Gourlet-Fleury Frédéric Mortier Adeline Fayolle Fidèle Baya Dakis Ouédraogo Fabrice Bénédet Nicolas Picard 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2013,368(1625)
Large areas of African moist forests are being logged in the context of supposedly sustainable management plans. It remains however controversial whether harvesting a few trees per hectare can be maintained in the long term while preserving other forest services as well. We used a unique 24 year silvicultural experiment, encompassing 10 4 ha plots established in the Central African Republic, to assess the effect of disturbance linked to logging (two to nine trees ha−1 greater than or equal to 80 cm DBH) and thinning (11–41 trees ha−1 greater than or equal to 50 cm DBH) on the structure and dynamics of the forest. Before silvicultural treatments, above-ground biomass (AGB) and timber stock (i.e. the volume of commercial trees greater than or equal to 80 cm DBH) in the plots amounted 374.5 ± 58.2 Mg ha−1 and 79.7 ± 45.9 m3 ha−1, respectively. We found that (i) natural control forest was increasing in AGB (2.58 ± 1.73 Mg dry mass ha−1 yr−1) and decreasing in timber stock (−0.33 ± 1.57 m3 ha−1 yr−1); (ii) the AGB recovered very quickly after logging and thinning, at a rate proportional to the disturbance intensity (mean recovery after 24 years: 144%). Compared with controls, the gain almost doubled in the logged plots (4.82 ± 1.22 Mg ha−1 yr−1) and tripled in the logged + thinned plots (8.03 ± 1.41 Mg ha−1 yr−1); (iii) the timber stock recovered slowly (mean recovery after 24 years: 41%), at a rate of 0.75 ± 0.51 m3 ha−1 yr−1 in the logged plots, and 0.81 ± 0.74 m3 ha−1 yr−1 in the logged + thinned plots. Although thinning significantly increased the gain in biomass, it had no effect on the gain in timber stock. However, thinning did foster the growth and survival of small- and medium-sized timber trees and should have a positive effect over the next felling cycle. 相似文献
67.
Summary As most georeferenced data sets are multivariate and concern variables of different types, spatial mapping methods must be able to deal with such data. The main difficulties are the prediction of non‐Gaussian variables and the modeling of the dependence between processes. The aim of this article is to present a new hierarchical Bayesian approach that permits simultaneous modeling of dependent Gaussian, count, and ordinal spatial fields. This approach is based on spatial generalized linear mixed models. We use a moving average approach to model the spatial dependence between the processes. The method is first validated through a simulation study. We show that the multivariate model has better predictive abilities than the univariate one. Then the multivariate spatial hierarchical model is applied to a real data set collected in French Guiana to predict topsoil patterns. 相似文献
68.
Le Goff C Mahaut C Wang LW Allali S Abhyankar A Jensen S Zylberberg L Collod-Beroud G Bonnet D Alanay Y Brady AF Cordier MP Devriendt K Genevieve D Kiper PÖ Kitoh H Krakow D Lynch SA Le Merrer M Mégarbane A Mortier G Odent S Polak M Rohrbach M Sillence D Stolte-Dijkstra I Superti-Furga A Rimoin DL Topouchian V Unger S Zabel B Bole-Feysot C Nitschke P Handford P Casanova JL Boileau C Apte SS Munnich A Cormier-Daire V 《American journal of human genetics》2011,89(1):7-14
Geleophysic (GD) and acromicric dysplasia (AD) belong to the acromelic dysplasia group and are both characterized by severe short stature, short extremities, and stiff joints. Although AD has an unknown molecular basis, we have previously identified ADAMTSL2 mutations in a subset of GD patients. After exome sequencing in GD and AD cases, we selected fibrillin 1 (FBN1) as a candidate gene, even though mutations in this gene have been described in Marfan syndrome, which is characterized by tall stature and arachnodactyly. We identified 16 heterozygous FBN1 mutations that are all located in exons 41 and 42 and encode TGFβ-binding protein-like domain 5 (TB5) of FBN1 in 29 GD and AD cases. Microfibrillar network disorganization and enhanced TGFβ signaling were consistent features in GD and AD fibroblasts. Importantly, a direct interaction between ADAMTSL2 and FBN1 was demonstrated, suggesting a disruption of this interaction as the underlying mechanism of GD and AD phenotypes. Although enhanced TGFβ signaling caused by FBN1 mutations can trigger either Marfan syndrome or GD and AD, our findings support the fact that TB5 mutations in FBN1 are responsible for short stature phenotypes. 相似文献
69.
JOACHIM GRÜNDEL ANDRZEJ KAIM ALEXANDER NÜTZEL CRISPIN T. S. LITTLE 《Palaeontology》2011,54(3):481-510
Abstract: Twenty‐five gastropod taxa are reported from the Early Jurassic (Hettangian to Toarcian) of England. Of these, 14 are identified to species level, and the remaining 11 are treated in open nomenclature. One genus (Lensataphrus) and six species are introduced as new. The new species are Lensataphrus tatei, Lensataphrus tenuis, Tricarilda toddi, Cylindrobullina dorsetensis, Cylindrobullina ventricosa and Consobrinella greeni. The following new combinations are introduced: Cassianopsis hebertana (d’Orbigny, 1852) for Neritopsis hebertana; Cryptaulax abscisum (Terquem and Piette, 1868) for Cerithium abscisum; and Cylindrobullina avena (Terquem, 1855) for Striactaeonina avena. Most of the genera and some of the species are also known from Central Europe (Germany and France). Typical vetigastropod genera that are present in England and Central Europe are Colpomphalus, Costataphrus, Ooliticia, Eucycloscala and Eucycloidea. The caenogastropod genera Levipleura and Cryptaulax are present in both regions, as are the heterobranchs Tricarilda and Cylindrobullina. The heterobranch genus Consobrinella is reported from England for the first time. Gastropods seem to follow the diversity trends of other marine invertebrates during the Early Jurassic. They diversify until the Late Pliensbachian but decrease sharply in number around the Pliensbachian–Toarcian boundary. This may reflect both regional anoxia and a global mass extinction event in the Early Toarcian. 相似文献
70.
Virginie Mortier Kenny Dauwe Leen Vancoillie Delfien Staelens Filip Van Wanzeele Dirk Vogelaers Linos Vandekerckhove Kristen Chalmet Chris Verhofstede 《PloS one》2013,8(11)