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The level of specialization of the entomopathogenic nematode Steinernema scapterisci with its native Xenorhabdus symbiont was investigated by testing (1) the influence of non-native bacterial strains on nematode fitness within an insect-host (Galleria mellonella) and (2) specificity of the association between the nematode infective juveniles and non-native(More)
Steinernema species are entomopathogenic nematodes. They are symbiotically associated with Enterobacteriaceae of the genus Xenorhabdus. These nematode–bacteria symbioses are extremely diversified and constitute an important new model in ecology and evolution to investigate symbioses between microbes and invertebrates. However, no study has so far adequately(More)
While the structure of the nucleosome core is known in atomic detail, the precise geometry of the DNA beyond the core particle is still unknown. We have used fluorescence resonance energy transfer (FRET) for determining the end-to-end distance of DNA fragments assembled with histones into nucleosomes. The DNA of a length of 150-220 bp was labeled with(More)
Using small angle neutron scattering we have measured the static form factor of two different superhelical DNAs, p1868 (1868 bp) and pUC18 (2686 bp), in dilute aqueous solution at salt concentrations between 0 and 1.5 M Na+ in 10 mM Tris at 0% and 100% D2O. For both DNA molecules, the theoretical static form factor was also calculated from an ensemble of(More)
The flexibility of the chromatin structure, necessary for the processing of the genomic DNA, is controlled by a number of factors where flexibility and mobility of the nucleosomes is essential. Here, the influence of DNA supercoiling on the structure of single nucleosomes is investigated. Circular supercoiled plasmid DNA sub-saturated with histones was(More)
The soluble proanthocyanidins of the coloured seed coats of Vicia faba L. were isolated and separated by solvent partition. The chemical characteristics of the proanthocyanidins were elucidated by total oxidation and partial degradation in the presence of phloroglucinol followed by HPLC analysis. The native extract of proanthocyanidins contained(More)
Carbon nanotubes (CNT) are a family of materials featuring a large range of length, diameter, numbers of walls and, quite often metallic impurities coming from the catalyst used for their synthesis. They exhibit unique physical properties, which have already led to an extensive development of CNT for numerous applications. Because of this development and(More)
Using a previously described FRET technique, we measured the distance between the ends of DNA fragments on which nucleosomes were reconstituted from recombinant and native histones. This distance was analyzed in its dependence on the DNA fragment length, concentration of mono- and divalent counterions, presence of linker histone H1, and histone(More)
X-ray fluorescence microscopy (microXRF) is applied for the first time to study macrophages exposed to unpurified and purified single-walled (SW) and multiwalled (MW) carbon nanotubes (CNT). Investigating chemical elemental distributions allows one to (i) image nanotube localization within a cell and (ii) detect chemical modification of the cell after CNT(More)
In southern France, Diplozoon gracile (Monogenea, Polyopisthocotylea), parasitizes four sympatric cyprinids. One of these host species, Barbus meridionalis, naturally hybridizes with another species of barbel, Barbus barbus, which is never parasitized by D. gracile under natural conditions. This hybridization has previously been studied and described as an(More)