Inclusion bodies: not that bad…

The formation of inclusion bodies constitute a frequent event during the production of heterologous proteins in bacterial hosts. Although the mechanisms leading to their formation are not completely understood, empirical data have been exploited trying to predict the aggregation propensity of specific proteins while a great number of strategies have been developed to avoid the generation of inclusion bodies. However, in many cases, the formation of such aggregates can be considered an advantage for basic research as for protein production. In this review, we focus on this positive side of IBs formation in bacteria. We present a compilation on recent advances on the understanding of inclusion bodies formation and their utilization as a model to understand protein aggregation and to explore strategies to control this process. We include recent information about their composition and structure, their use as an attractive approach to produce low cost proteins and other promising applications in Biomedicine

Informe final del proyecto: Optimización de las técnicas de edición genómica libres de ADN utilizando un modelo de resistencia a herbicida

Las metodologías de edición genómica, especialmente aquellas basadas en el sistema CRISPR/Cas9 se han establecido en los últimos años como herramientas poderosas al servicio del mejoramiento vegetal. Recientemente se han reportado metodologías de edición genómica “libres de DNA” en plantas, las cuales garantizan la no incorporación de ADN foráneo al genoma y confieren ventajas a las variedades editadas desde el punto de vista de su regulación. Algunos países, entre ellos Estados Unidos y países de la región (Argentina y Brasil), han optado por una regulación en la que no se considera a los organismos editados dentro de la categoría de OGM. Esto repercutirá en la reducción de costos y tiempos de liberación de las nuevas variedades, así como en la percepción pública sobre los alimentos derivados de ellas. Resulta ventajoso que nuestro país se mantenga actualizado en las tecnologías que apoyan el mejoramiento vegetal. En este sentido, este proyecto buscó generar dos productos de utilidad: primero, una metodología optimizada para la edición genómica libre de DNA y segundo, una metodología de remplazo alélico valiéndose del sistema CRISPR/Cas9.Agencia Nacional de Investigación e Innovació

Oxygen spectroscopy and polarization-dependent imaging contrast (PIC)-mapping of calcium carbonate minerals and biominerals

X-ray absorption near-edge structure (XANES) spectroscopy and spectromicroscopy have been extensively used to characterize biominerals. Using either Ca or C spectra, unique information has been obtained regarding amorphous biominerals and nanocrystal orientations. Building on these results, we demonstrate that recording XANES spectra of calcium carbonate at the oxygen K-edge enables polarization-dependent imaging contrast (PIC) mapping with unprecedented contrast, signal-to-noise ratio, and magnification. O and Ca spectra are presented for six calcium carbonate minerals: aragonite, calcite, vaterite, monohydrocalcite, and both hydrated and anhydrous amorphous calcium carbonate. The crystalline minerals reveal excellent agreement of the extent and direction of polarization dependences in simulated and experimental XANES spectra due to X-ray linear dichroism. This effect is particularly strong for aragonite, calcite, and vaterite. In natural biominerals, oxygen PIC-mapping generated high-magnification maps of unprecedented clarity from nacre and prismatic structures and their interface in Mytilus californianus shells. These maps revealed blocky aragonite crystals at the nacre-prismatic boundary and the narrowest calcite needle-prisms. In the tunic spicules of Herdmania momus, O PIC-mapping revealed the size and arrangement of some of the largest vaterite single crystals known. O spectroscopy therefore enables the simultaneous measurement of chemical and orientational information in CaCO3 biominerals and is thus a powerful means for analyzing these and other complex materials. As described here, PIC-mapping and spectroscopy at the O K-edge are methods for gathering valuable data that can be carried out using spectromicroscopy beamlines at most synchrotrons without the expense of additional equipment