Compositional equivalence of event IND-ØØ412-7 to non-transgenic wheat.

Wheat is the most widely grown cereal grain, occupying a significant portion of the total cultivated land. As drought is the major environmental stressor affecting crop production, yield maintenance under water deficit conditions appears as a highly desirable phenotype for crop improvement. The HaHB4 (Helianthus annuus homeobox 4) gene from sunflower encodes for a transcription factor involved in tolerance to environmental stress. The introduction of HaHB4 in wheat led to the development of event IND-ØØ412-7 (HB4® wheat), which displayed higher yield in production environments of low productivity potential. Compositional analysis of IND-ØØ412-7 wheat, including 41 nutrients and 2 anti-nutrients for grain and 10 nutrients in forage, was performed. Results of these studies indicated that IND-ØØ412-7 is compositionally equivalent to non-transgenic wheat.

Cultivo de condrocitos sobre una matriz acelular derivada de membrana amniocoriónica / Culture of chondrocytes on an acellular matrix derived from amniochorionic membrane

Introducción: El tejido cartilaginoso articular presenta escasa capacidad regenerativa. Existe alta incidencia de lesiones condrales en la rodilla, especialmente de grado II/III (Outerbridge). El uso combinado de células autólogas cultivadas con membranas biológicas es una posibilidad terapéutica. El objetivo del presente trabajo es analizar las características del desarrollo in vitro de condrocitos humanos sobre una membrana amniocoriónica acelular (MAC) desecada. Materiales y métodos: Entre diciembre de 2010 y diciembre de 2011 se procesaron 16 muestras de cartílago de donante vivo, de las cuales se analizaron siete. Los condrocitos fueron cultivados y amplificados sobre plástico, a partir de lo cual se realizaron los siguientes análisis: interacción entre células y MAC, capacidad de la MAC como matriz para las células y comportamiento de las células cultivadas sobre la MAC. Resultados: Los condrocitos in vitro mostraron cambios fenotípicos en presencia de MAC. Las células fueron capaces de adherirse y permanecer en la región esponjosa de la membrana. La microscopia electrónica de las MAC cultivadas mostró la presencia de células, organelas celulares bien conservadas, retículo endoplásmico y uniones de tipo desmosoma. Conclusiones: Este trabajo muestra la factibilidad de cultivar condrocitos sobre MAC. Las células fueron capaces de adherirse, permanecer y diferenciarse sobre la membrana durante el tiempo del estudio

Serratia marcescens is able to survive and proliferate in autophagic-like vacuoles inside non-phagocytic cells.

Serratia marcescens is an opportunistic human pathogen that represents a growing problem for public health, particularly in hospitalized or immunocompromised patients. However, little is known about factors and mechanisms that contribute to S. marcescens pathogenesis within its host. In this work, we explore the invasion process of this opportunistic pathogen to epithelial cells. We demonstrate that once internalized, Serratia is able not only to persist but also to multiply inside a large membrane-bound compartment. This structure displays autophagic-like features, acquiring LC3 and Rab7, markers described to be recruited throughout the progression of antibacterial autophagy. The majority of the autophagic-like vacuoles in which Serratia resides and proliferates are non-acidic and have no degradative properties, indicating that the bacteria are capable to either delay or prevent fusion with lysosomal compartments, altering the expected progression of autophagosome maturation. In addition, our results demonstrate that Serratia triggers a non-canonical autophagic process before internalization. These findings reveal that S. marcescens is able to manipulate the autophagic traffic, generating a suitable niche for survival and proliferation inside the host cell.

Enterobacterial common antigen integrity is a checkpoint for flagellar biogenesis in Serratia marcescens.

Serratia marcescens strains are ubiquitous bacteria isolated from environmental niches, such as soil, water, and air, and also constitute emergent nosocomial opportunistic pathogens. Among the numerous extracellular factors that S. marcescens is able to produce, the PhlA phospholipase is the only described exoprotein secreted by the flagellar apparatus while simultaneously being a member of the flagellar regulon. To gain insight into the regulatory mechanism that couples PhlA and flagellar expression, we conducted a generalized insertional mutagenesis and screened for PhlA-deficient strains. We found that three independent mutations in the wec cluster, which impaired the assembly of enterobacterial common antigen (ECA), provoked the inhibition of PhlA expression. Swimming and swarming assays showed that in these strains, motility was severely affected. Microscopic examination and flagellin immunodetection demonstrated that a strong defect in flagellum expression was responsible for the reduced motility in the wec mutant strains. Furthermore, we determined that in the ECA-defective strains, the transcriptional cascade that controls flagellar assembly was turned off due to the down-regulation of flhDC expression. These findings provide a new perspective on the physiological role of the ECA, providing evidence that in S. marcescens, its biosynthesis conditions the expression of the flagellar regulon.