Hernandez-Pinzon I.,Center for Research in Agricultural Genomics |
Hernandez-Pinzon I.,Norwich Research Park |
Cifuentes M.,Center for Research in Agricultural Genomics |
Cifuentes M.,French National Institute for Agricultural Research |
And 5 more authors.
Retrotransposons' high capacity for mutagenesis is a threat that genomes need to control tightly. Transcriptional gene silencing is a general and highly effective control of retrotransposon expression. Yet, some retrotransposons manage to transpose and proliferate in plant genomes, suggesting that, as shown for plant viruses, retrotransposons can escape silencing. However no evidence of retrotransposon silencing escape has been reported. Here we analyze the silencing control of the tobacco Tnt1 retrotransposon and report that even though constructs driven by the Tnt1 promoter become silenced when stably integrated in tobacco, the endogenous Tnt1 elements remain active. Silencing of Tnt1-containing transgenes correlates with high DNA methylation and the inability to incorporate H2A.Z into their promoters, whereas the endogenous Tnt1 elements remain partially methylated at asymmetrical positions and incorporate H2A.Z upon induction. Our results show that the promoter of Tnt1 is a target of silencing in tobacco, but also that endogenous Tnt1 elements can escape this control and be expressed in their natural host. © 2012 Hernández-Pinzón et al. Source
Tintore M.,Barcelona Institute for Research in Biomedicine |
Gallego I.,Barcelona Institute for Research in Biomedicine |
Gallego I.,Georgia Institute of Technology |
Manning B.,Barcelona Institute for Research in Biomedicine |
And 3 more authors.
Angewandte Chemie - International Edition
The folding of DNA molecules by DNA origami is used in a nanosensor to analyze enzymatic DNA repair activity of hAGT. The method uses conformational changes that condition α-thrombin interaction with DNA aptamers, and illustrates the use of DNA origami as a proteinrecognition biosensor. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source
Forastiero R.,Favaloro University |
Papalardo E.,University of Texas Medical Branch |
Watkins M.,Bio Rad Laboratories Inc. |
Nguyen H.,Bio Rad Laboratories Inc. |
And 14 more authors.
Clinica Chimica Acta
Background: The performance and standardization of anticardiolipin (aCL) and anti-β2 glycoprotein I antibodies (aβ2GPI) tests for the confirmation of diagnosis of antiphospholipid syndrome (APS) remain a matter of debate and concern. We evaluated the performance of different ELISAs and other new immunoassays for the detection of aCL and aβ2GPI in a wet workshop at the 13th International Congress on Antiphospholipid Antibodies in Galveston, TX (April 13th, 2010, APLA 2010). Methods: Aliquots of 26 un-identified APS or persistently aPL positive serum samples and 21 controls (9 from healthy individuals and 5 from patients with infectious diseases and 7 with various autoimmune diseases) were distributed to all participants/groups. All serum samples were evaluated in various aCL and aβ2GPI ELISAs, a chemiluminescent immunoassay, a fluoro-enzyme immunoassay, and in a multiplexed immunoassay system. Monoclonal and polyclonal calibrators were also evaluated. Results: Although not all the assays reported the titers of aCL and aβ2GPI in the same units, the correlation of positive titers among the assays was good. All aCL and aβ2GPI tests showed excellent clinical sensitivities, specificities and positive predictive values and good agreement with respect to the levels of the IgG and IgM antibodies, regardless of assay type, or whether tests were done using automated or "manual" systems. Conclusions: New methodologies for the detection of aPL look promising and comparable to currently approved ELISA tests. This study provides evidence of progress of efforts of harmonization of tests used to detect aPL. © 2013 Elsevier B.V. Source
Shui L.,MESA Institute for Nanotechnology |
Shui L.,South China Normal University |
Sparreboom W.,MESA Institute for Nanotechnology |
Spang P.,Fraunhofer Institute of Microtechnology Mainz |
And 6 more authors.
We report a new DNA fragmentation technique that significantly simplifies conventional hydrodynamic shearing fragmentation by eliminating the need for sample recirculation while maintaining high fragmentation yield and low fragment length variation, and therefore, reduces instrument complexity and cost, increases fragmentation throughput and is well suited for integration in a lab-on-a-chip platform. The new DNA shearing technique is realized in a microfluidic lab on a chip (LOC) consisting of a chain of series-connected constriction channels that are each separated by a long spacer channel with much larger cross-sectional area. A sample injected to the microfluidic structure undergoes multiple acceleration-deceleration cycles at each constriction channel where the fluid induces strain to the DNA molecules necessary to induce the double chain scission fragmentation, which has a similar effect as multiple recirculation cycles. Experimental results show that the new fragmentation technique improves the fragmentation yield of genomic DNA from 10% for single constriction channels up to 90% for multiple series connected constriction channels. © 2013 The Royal Society of Chemistry. Source