PAMP-triggered immunity against Pseudomonas syringae involves microRNA-mediated regulation of several uncharacterized R genes

Two main types of noncoding small RNA molecules have been found in plants: microRNAs (miRNAs) and small interfering RNAs (siRNAs). They differ in their biogenesis and mode of action, but share similar sizes (20-24 nt). Their precursors are processed by Dicer-Like RNase III (dcl) proteins present in Arabidopsis thaliana, and in their mature form can act as negative regulators of gene expression, being involved in a vast array of plant processes, including plant development, genomic integrity or response to stress. Small-RNA mediated regulation can occurs at transcriptional level (TGS) or at post-transcriptional level (PTGS). In recent years, the role of gene silencing in the regulation of expression of genes related to plant defence responses against bacterial pathogens is becoming clearer. Comparisons carried out in our lab between the expression profiles of different mutants affected in gene silencing, and plants challenged with Pseudomonas syringae pathovar tomato DC3000, led us to identify a set of uncharacterized R genes, belonging to the TIR-NBS-LRR gene family, differentially expressed in these conditions. Through the use of bioinformatics tools, we found a miRNA* of 22 nt putatively responsible for down-regulating expression of these R genes through the generation of siRNAs. We have also found that the corresponding pri-miRNA is down-regulated after PAMP-perception in a SA-dependent manner. We also demonstrate that plants with altered levels of miRNA* (knockdown lines or overexpression lines) exhibit altered PTI-associated phenotypes, suggesting a role for this miRNA* in this defence response against bacteria. In addition we identify one of the target genes as a negative regulator of defence response against Pseudomonas syringae.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. MINECO, FEDE

Sobre arqueologías de liberación en una “colonia postcolonial” (Puerto Rico).

This paper analyzes some historical and recent issues of the archaeological practices that are taking place in Puerto Rico and other eccentric contexts in order to expose the multiple vectors of colonialism that are embedded today in the structure and praxis of the discipline. Some of the recent manifestations of postcolonial thought (and its respective critiques) are used to contextualize the atypical socio-political situation of Puerto Rico, which has been recently characterized as a “postcolonial colony.” We suggest that the socio political context in which the archaeology of Puerto Rico was created and developed influenced enormously the structure of the discipline in the island, which has led to a colonized production of knowledge, narratives, and representations of our ancient history. We propose, as an alternative against the naturalization of colonialism in the practice of archaeology in the island and other eccentric territories, the articulation of a new moral and ethical order within the discipline that we have named “archaeologies of liberation”.Este artículo analiza algunos elementos históricos y recientes de la práctica arqueológica mundial y de Puerto Rico, con la finalidad de exponer los múltiples vectores de colonialismo existentes en la praxis y narrativa de la disciplina, tanto a nivel local como global. El eje central del presente análisis se fundamenta en algunas de las recientes manifestaciones del pensamiento postcolonial mundial (y las críticas hechas a éste) para situar a Puerto Rico en el atípico escenario sociopolítico en el que se encuentra. Se plantea que el contexto sociopolítico en el cual se creó y desarrolló la arqueología de Puerto Rico influyó enormemente en la estructura de esta disciplina, provocando que la producción de conocimientos sobre nuestra historia antigua haya estado (y siga estando) condicionada a prácticas, narrativas y representaciones culturales de carácter colonial. Proponemos, como alternativa en contra de la naturalización del colonialismo en la arqueología de la Isla y de otros territorios excéntricos, el surgimiento y desarrollo de un nuevo orden moral y ético al interior de la disciplina, el cual hemos denominado “arqueologías de liberación”

Herbage Mass and \u3cem\u3ein Situ\u3c/em\u3e Dry Matter Ruminal Degradation Kinetics of \u3cem\u3eBrachiaria\u3c/em\u3e spp

In Puerto Rico, Brachiaria decumbens cv. Basilisk has been promoted as a potential forage for acid soils and humid areas, but with limited success. Recently, B. brizantha cv. Marandú and a hybrid (B. brizantha x B. Ruziziensis) cv. Mulato were introduced for evaluation on acid soils and as a potential replacement for cv. Basilisk, but little information is available on yield performance under grazing or nutritive value. The objective of this study was to assess herbage mass and nutritive value of grazed pastures consisting of Basilisk, Marandú, and Mulato and determine the rate of in situ dry matter degradation

R gene regulation mediated by miRNA/phasiRNA during plant defense response against P. syringae

In plants, two main types of noncoding small RNA molecules have been found: microRNAs (miRNAs) and small interfering RNAs (siRNAs), differing these in their biogenesis and mode of action, but sharing similar sizes (20-24 nt). In plants, their mature forms are products of the activity of DCL proteins and can act as negative regulators of gene expression. In recent years, the role of miRNAs in regulation of gene expression in plant responses against bacterial pathogens is becoming clearer. Comparisons carried out in our lab between expression profiles of different Arabidopsis thaliana mutants affected in gene silencing, and plants challenged with Pseudomonas syringae pathovar tomato DC3000, led us to identify a set of uncharacterized R genes, belonging to the TIR-NBS-LRR gene family, as differentially expressed in these conditions. By bioinformatics tools, we found a miRNA* of 22 nt putatively responsible for down-regulating expression of these R genes. We have also found that the corresponding pri-miRNA is down-regulated after PAMP-perception. We demonstrate that plants with altered levels of this miRNA* (knockdown lines or overexpression lines) exhibit altered PTI-associated phenotypes, suggesting a role for this miRNA* in this defence response against bacteria. We have characterized the expression pattern of both primiRNA and its best target R genes. Finally, we identify phasiRNAs that arise from the transcript of this R gen in a miRNA*-RDR6-DCL4-dependent mannerUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Regulación de genes de resistencia de la familia TIR-NBS-LRR mediada por miRNA/phasiRNA durante la interacción con P. syringae

Durante un estrés biótico, las plantas modulan la expresión de una batería de genes involucrados en la respuesta de defensa, proceso donde recientemente se ha determinado el papel esencial que desempeña el silenciamiento génico. El silenciamiento génico es un mecanismo de regulación de la expresión génica, donde destacan como principales moléculas efectoras los pequeños RNAs (sRNAs). En plantas, estos sRNAs, son clasificados en pequeños RNAs interferentes (siRNAs) o microRNAs (miRNAs), presentando tamaños similares (20-24 nt) pero difiriendo en su biogénesis y modo de acción. Los miRNAs son pequeños RNAs de cadena sencilla que actúan regulando negativamente la expresión de genes, mediante su unión al complejo RISC (Rna Induced Silencing Complex) y en una forma dependiente de secuencia. En nuestro laboratorio, mediante el análisis de datos transcriptómicos, y el uso de herramientas bioinformáticas, identificamos un miRNA* de 22 nt como potencial regulador de la expresión de genes de resistencia (“R”) del tipo TIR-NBS-LRR. Posteriormente hemos validado dicha regulación y caracterizado los patrones de expresión tanto del Pri-miRNA como de un gen “R” regulado por este, en diferentes tejidos y estadios del desarrollo, así como durante la interacción con P. syringae. Por otro lado, hemos generado plantas transgénicas que presentan niveles alterados del miRNA* (incremento y reducción) y hemos observado que muestran fenotipos alterados de PTI y una mayor/menor colonización de P. syringae. Finalmente hemos identificado la producción de sRNAs (phasiRNAs) a partir del gen de resistencia, en una forma dependiente de miRNA*-RDR6-DCL4, pudiendo estos sRNAs secundarios regular otros transcritos de la misma familia de genes de resistencia.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Sinusoidal Endothelial Dysfunction Precedes Inflammation and Fibrosis in a Model of NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. Most morbidity associated with the metabolic syndrome is related to vascular complications, in which endothelial dysfunction is a major pathogenic factor. However, whether NAFLD is associated with endothelial dysfunction within the hepatic vasculature is unknown. The aims of this study were to explore, in a model of diet-induced overweight that expresses most features of the metabolic syndrome, whether early NAFLD is associated with liver endothelial dysfunction. Wistar Kyoto rats were fed a cafeteria diet (CafD; 65% of fat, mostly saturated) or a control diet (CD) for 1 month. CafD rats developed features of the metabolic syndrome (overweight, arterial hypertension, hypertryglyceridemia, hyperglucemia and insulin resistance) and liver steatosis without inflammation or fibrosis. CafD rats had a significantly higher in vivo hepatic vascular resistance than CD. In liver perfusion livers from CafD rats had an increased portal perfusion pressure and decreased endothelium-dependent vasodilation. This was associated with a decreased Akt-dependent eNOS phosphorylation and NOS activity. In summary, we demonstrate in a rat model of the metabolic syndrome that shows features of NAFLD, that liver endothelial dysfunction occurs before the development of fibrosis or inflammation

Religión y personas de 60 años o más en Puerto Rico: características sociodemográficas y el estado de salud, 2002-2003

Actualmente, Puerto Rico está atravesando la transición demográfica, lo que provoca que la población envejecida esté aumentando. Este reto es debido a la reducción en las tasas de natalidad, las altas tasas de migración, las tasas de mortalidad; el mismo tiene diversas implicaciones sociales. La religión, como elemento pro-social, sirve como herramienta para lidiar con los diversos desafíos que atraviesan los adultos mayores; demostrando una influencia positiva en la vida y en la salud de estos individuos. No obstante, la religión como factor en las investigaciones demográficas, no ha sido estudiada en Puerto Rico. Por consiguiente, existe una necesidad de proveer información sobre las características sociodemográficas de las personas de 60 años o más por grupo religioso, sus características religiosas, sus redes de apoyo y su estado de salud, ya que estas variables influyen en la vida del envejecido. Se utilizó un estudio descriptivo, trabajando con la base de datos “Condiciones de Salud de los Adultos de Edad Mayor en Puerto Rico: 2002-2003” (conocido por sus siglas en inglés, PREHCO). Los resultados y discusión de este trabajo, les proveerán a los lectores un mejor marco para estudiar la influencia de la religión en estos individuos. Además, se espera que esta investigación despierte el interés de profesionales de la salud y líderes religiosos, para así poder realizar distintos planes de acción o políticas públicas para trabajar con esta población vulnerable

Electrochemical Study and Preparation of Gold Substrates Functionalized with Single-Walled Carbon Nanotubes for DNA Biosensor Application

We report here the use of self-assembled monolayer (SAM) on gold modified with single-walled carbon nanotubes (SWNTs) as a suitable substrate for deoxyribonucleic acid (DNA) oligonucleotides attachment. For our purpose, the molecule 4-aminothiophenol (4-ATP) was self-assembled on gold by forming a thiolate (Au-S) bond. The amine terminal group of the SAM was used to covalently link SWNTs, which serve as template for the covalent attachment of DNA. Each step was characterized by cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR)