Electrochemical oxidation of urea on nickel-rhodium nanoparticles/carbon composites

International audienc

Detection of genetic variation and base modifications at base-pair resolution on both DNA and RNA

International audienceAccurate decoding of nucleic acid variation is critical to understand the complexity and regulation of genome function. Here we use a single-molecule magnetic tweezer (MT) platform to identify sequence variation and map a range of important epigenetic base modifications with high sensitivity, specificity, and precision in the same single molecules of DNA or RNA. We have also developed a highly specific amplification-free CRISPR-Cas enrichment strategy to isolate genomic regions from native DNA. We demonstrate enrichment of DNA from both E. coli and the FMR1 5'UTR coming from cells derived from a Fragile X carrier. From these kilobase-length enriched molecules we could characterize the differential levels of adenine and cytosine base modifications on E. coli, and the repeat expansion length and methylation status of FMR1. Together these results demonstrate that our platform can detect a variety of genetic, epigenetic, and base modification changes concomitantly within the same single molecules

Detecting genetic variation and base modifications together in the same single molecules of DNA and RNA at base pair resolution using a magnetic tweezer platform

Accurate decoding of nucleic acid variation is important to understand the complexity and regulation of genome function. Here we introduce a single-molecule platform based on magnetic tweezer (MT) technology that can identify and map the positions of sequence variation and multiple base modifications together in the same single molecules of DNA or RNA at single base resolution. Using synthetic templates, we demonstrate that our method can distinguish the most common epigenetic marks on DNA and RNA with high sensitivity, specificity and precision. We also developed a highly specific CRISPR-Cas enrichment strategy to target genomic regions in native DNA without amplification. We then used this method to enrich native DNA from E. coli and characterized the differential levels of adenine and cytosine base modifications together in molecules of up to 5 kb in length. Finally, we enriched the 5‘UTR of FMR1 from cells derived from a Fragile X carrier and precisely measured the repeat expansion length and methylation status of each molecule. These results demonstrate that our platform can detect a variety of genetic, epigenetic and base modification changes concomitantly within the same single molecules

Les Saints et les Anges...

Tous les anges ne sont pas des saints, tous les morts éminents ne sont pas voués à être des saints hommes, et tous les héros ou les saints ne sont pas des martyrs. La plasticité et la multiplicité de ces êtres extra-ordinaires, construits à la frontière du monde des dieux et des hommes, du sacré et du politique, de la mystique et de la guérison, permettent néanmoins de comprendre les vertus de médiation et d’intercession, qui en font plus que jamais des acteurs de la modernité religieuse. Les figures revisitées des saints, héros et martyrs, sont au fondement de l’invention moderne de nouvelles traditions locales, et servent de relais à une culture de pèlerinage urbaine et contemporaine qui traduit aussi bien les affirmations identitaires des groupes ethniques ou nationaux que les contradictions de l’impératif de l’individualité