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1.
Marie-Laure Yaspo Nathalie Crété Zoubida Chettouh Jean-Louis Blouin Zohra Rahmani Dominique Stehelin Pierre-Marie Sinet Nicole Créau-Goldberg Jean-Maurice Delabar 《Human genetics》1992,90(4):427-434
To generate new chromosome 21 markers in a region that is critical for the pathogenesis of Down syndrome (D21S55-MX1), we used pulsed field gel electrophoresis (PFGE) to isolate a 600-kb NruI DNA fragment from the WA17 hybrid cell line, which has retained chromosome 21 as the only human material. This fragment, which contains the oncogene ETS2, was used to construct a partial genomic library. Among the 14 unique sequences that were isolated, 3 were polymorphic markers and contained sequences that are conserved in mammals. Five of these markers mapped on the ETS2-containing NruI fragment and allowed us to define an 800-kb high-resolution PFGE map. 相似文献
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Deficiency in coagulation factor IX, a plasma glycoprotein constituent of the clotting cascade, results in hemophilia B, an inherited recessive X-linked bleeding disorder. Some affected individuals, referred to as antigen positive or CRM+, express an inactive factor IX gene product at normal levels and are expected to have natural mutations altering domains of the molecule that are critical for its correct function. The serine protease catalytic domain of activated factor IX, encoded by exons VII and VIII of the gene, is a possible target for such mutations. We designed a strategy allowing rapid analysis of this region through enzymatic amplification of genomic DNA, analysis of the amplification products by denaturing gradient gel electrophoresis, and direct sequencing of the fragments displaying an altered melting behavior. This procedure permitted us to characterize two previously undescribed mutations. Factor IX Angers is a G-to-A substitution generating an Arg in place of a Gly at amino acid 396 of the mature factor IX protein. Factor IX Bordeaux is an A-to-T substitution introducing a nonsense codon in place of the normal codon for Lys at position 411. Moreover, the already described factor IX Vancouver defect was found in three apparently independent families. These results provide further insight into the molecular heterogeneity of hemophilia B. In addition, we demonstrate the usefulness of this rapid screening procedure, which has broad applications in human genetics and can be used as an alternative to RFLP analysis in carrier detection or prenatal diagnosis studies. 相似文献
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Jérôme Lavergne 《BBA》1982,679(1):12-18
Chloroplasts were submitted to a sequence of saturating short flashes and then rapidly mixed with dichlorophenyldimethylurea (DCMU). The amount of singly reduced secondary acceptor (B?) present was estimated from the DCMU-induced increase in fluorescence in the dark caused by the reaction: QB? Q?B. By varying the time interval between the preillumination and the mixing, the time course of B? reoxidation by externally added benzoquinone was investigated. It was found that benzoquinone oxidizes B? in a bimolecular reaction, and does not interact directly with Q?. When a sufficient delay after the preillumination was allowed in order to let benzoquinone reoxidize B? before the injection of DCMU, the fluorescence increase caused by one subsequent flash fired in the presence of DCMU was followed by a fast decay phase (). The amplitude of this phase was proportional to the amount of B? produced by the preillumination. This fast decay was observed only after the first flash in the presence of DCMU. These results are interpreted by assuming a binding of the singly reduced benzoquinone to Photosystem II where it acts as an efficient, DCMU-insensitive, secondary (exogenous) acceptor. 相似文献
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Stage dependent synthesis of heat shock induced proteins in early embryos of Drosophila melanogaster
Jean-Maurice Dura 《Molecular & general genetics : MGG》1981,184(3):381-385
Summary The synthesis of heat shock proteins (hsp) has been examined during the early embryogenesis of Drosophila melanogaster. Normal protein synthesis stops after heat shock at all developmental stages, while hsp synthesis is induced only after treatment at blastoderm and later stages. The small hsps continue to be synthesised after heat shock for a longer period than the larger ones. Heat shocks at 35°C, 37°C and 40°C were compared for their effect on hsp synthesis and the effect of heat shock on the normal course of development was analysed. 相似文献
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Wilfried Thuiller Luigi Maiorano Florent Mazel Fran?ois Guilhaumon Gentile Francesco Ficetola Sébastien Lavergne Julien Renaud Cristina Roquet David Mouillot 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2015,370(1662)
Protected areas (PAs) are pivotal tools for biodiversity conservation on the Earth. Europe has had an extensive protection system since Natura 2000 areas were created in parallel with traditional parks and reserves. However, the extent to which this system covers not only taxonomic diversity but also other biodiversity facets, such as evolutionary history and functional diversity, has never been evaluated. Using high-resolution distribution data of all European tetrapods together with dated molecular phylogenies and detailed trait information, we first tested whether the existing European protection system effectively covers all species and in particular, those with the highest evolutionary or functional distinctiveness. We then tested the ability of PAs to protect the entire tetrapod phylogenetic and functional trees of life by mapping species'' target achievements along the internal branches of these two trees. We found that the current system is adequately representative in terms of the evolutionary history of amphibians while it fails for the rest. However, the most functionally distinct species were better represented than they would be under random conservation efforts. These results imply better protection of the tetrapod functional tree of life, which could help to ensure long-term functioning of the ecosystem, potentially at the expense of conserving evolutionary history. 相似文献
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Benoit de Thoisy Hervé Bourhy Marguerite Delaval Dominique Pontier Laurent Dacheux Edith Darcissac Damien Donato Amandine Guidez Florence Larrous Rachel Lavenir Arielle Salmier Vincent Lacoste Anne Lavergne 《PLoS neglected tropical diseases》2016,10(1)
Introduction
In addition to the commonly accepted importance of the vampire bat in the maintenance and transmission of the rabies virus (RABV) in South America, RABV infection of other species is widely evidenced, challenging their role in the viral cycle.Methodology / Principles findings
To identify the bioecological drivers of RABV circulation in neotropical bat communities, we conducted a molecular and serological survey on almost 1,000 bats from 30 species, and a 4-year longitudinal survey in two colonies of vampire bats in French Guiana. RABV was molecularly detected in a common vampire and in a frugivorous bat. The sequences corresponded to haematophagous bat-related strains and were close to viruses circulating in the Brazilian Amazon region. Species’ seroprevalence ranged from 0 to 20%, and the risk of seropositivity was higher in bats with a haematophagous diet, living in monospecific colonies and in dense forests. The longitudinal survey showed substantial temporal fluctuations, with individual waves of seroconversions and waning immunity. The high prevalences observed in bat communities, in most habitats and in species that do not share the same microhabitats and bioecological patterns, the temporal variations, and a rather short period of detectable antibodies as observed in recaptured vampires suggest (i) frequent exposure of animals, (ii) an ability of the infected host to control and eliminate the virus, (iii) more relaxed modes of exposure between bats than the commonly assumed infection via direct contact with saliva of infected animals, all of which should be further investigated.Conclusions / significance
We hypothesize that RABV circulation in French Guiana is mainly maintained in the pristine forest habitats that may provide sufficient food resources to allow vampire bats, the main prevalent species, to survive and RABV to be propagated. However, on the forest edge and in disturbed areas, human activities may induce more insidious effects such as defaunation. One of the ecological consequences is the disappearance of resources for tertiary or secondary consumers. Populations of vampires may then shift to alternative resources such as cattle, domestic animals and humans. Therefore, a good forest status, allowing both a dilution effect in highly rich bat communities and the maintenance of large populations of medium-sized and large mammals used as prey by vampires, should prevent their migration to anthropized areas. 相似文献10.
J. Pruonosa L. Parera C. Peraire F. Pla O. Lavergne R. Obach 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1995,668(2)
A sensitive and selective HPLC-solid-phase extraction procedure was developed for the determination of platelet-activating factor antagonist BN-50727 and its metabolites in human plasma. The procedure consisted of an automated solid-phase extraction of the drug and metabolites on disposable propylcarboxylic acid cartridges, followed by on-line chromatographic separation. The method was linear from 3.75 to 2400 ng/ml and the limit of quantitation for BN-50727 in plasma samples was 3.75 ng/ml. The within-run precision of the method, expressed as relative standard deviation, ranged from 2.1 to 8.1%. The accuracy, expressed as relative error, ranged from −3.5 to 4.0%. For the main metabolite, the O-demetthylated BN-50727 product, the method was linear from 7.5 to 2400 ng/ml and the limit of quantitation in plasma was 7.5 ng/ml. The within-run precision ranged from 2.1 to 11.0% and the accuracy from −5.3 to 1.1%. This paper describes the validation of the analytical methodology for the determination of BN-50727 in human plasma and also of its metabolites. The method has been used to follow the time course of BN-50727 and its metabolites in human plasma after administration of single and multiple doses. 相似文献