317 research outputs found

    Aislados de Bacillus provenientes de la rizósfera de cactus incrementan la germinación y la floración en Mammillaria spp. (Cactaceae)

    Get PDF
    ResumenLas cactáceas son la vegetación característica de las zonas áridas en México, donde las lluvias son escasas, la evapotranspiración es elevada y la fertilidad de los suelos es baja. Las plantas han desarrollado estrategias fisiológicas como la asociación con microorganismos en la zona de la rizósfera para incrementar la captación de nutrientes. En el presente trabajo se obtuvieron 4 aislados bacterianos de la rizósfera de Mammillaria magnimamma y Coryphantha radians, los que fueron nombrados como QAP3, QAP19, QAP22 y QAP24 e identificados genéticamente como pertenecientes al género Bacillus. Estos aislados exhibieron in vitro propiedades bioquímicas como solubilización de fosfatos, producción de ácido indolacético y actividad ACC deaminasa, que se relacionan con la promoción del crecimiento de las plantas. Dicha promoción fue ensayada inoculando semillas de M. magnimamma y evaluando luego algunos parámetros. Se encontró que todos los aislados incrementaron la germinación desde un 17% hasta un 34,3% (con respecto a las semillas testigo sin inocular); el aislado QAP24 fue el que presentó el mayor efecto en este sentido y permitió la germinación de todas las semillas viables (84,7%) 3 días antes que en el testigo. La inoculación de este aislado en plantas de Mammillaria zeilmanniana mostró un efecto positivo sobre la floración: en 2 meses dentro del período de un año se detectó un incremento en el número de plantas en floración con respecto a las plantas testigo, de hasta el 31,0% en uno de ellos. Se concluye que los aislados de Bacillus spp. caracterizados poseen potencial para ser empleados en programas de conservación de especies vegetales de zonas áridas.AbstractCacti are the most representative vegetation of arid zones in Mexico where rainfall is scarce, evapotranspiration is high and soil fertility is low. Plants have developed physiological strategies such as the association with microorganisms in the rhizosphere zone to increase nutrient uptake. In the present work, four bacterial isolates from the rhizosphere of Mammillaria magnimamma and Coryphantha radians were obtained and named as QAP3, QAP19, QAP22 and QAP24, and were genetically identified as belonging to the genus Bacillus, exhibiting in vitro biochemical properties such as phosphate solubilization, indoleacetic acid production and ACC deaminase activity related to plant growth promotion, which was tested by inoculating M. magnimamma seeds. It was found that all isolates increased germination from 17 to 34.3% with respect to the uninoculated control seeds, being QAP24 the one having the greatest effect, accomplishing the germination of viable seeds (84.7%) three days before the control seeds. Subsequently, the inoculation of Mammillari zeilmanniana plants with this isolate showed a positive effect on bloom, registering during two months from a one year period, an increase of up to 31.0% in the number of flowering plants compared to control plants. The characterized Bacillus spp. isolates have potential to be used in conservation programs of plant species from arid zones

    A Yap-dependent mechanoregulatory program sustains cell migration for embryo axis assembly

    Get PDF
    The assembly of the embryo’s primary axis is a fundamental landmark for the establishment of the vertebrate body plan. Although the morphogenetic movements directing cell convergence towards the midline have been described extensively, little is known on how gastrulating cells interpret mechanical cues. Yap proteins are well-known transcriptional mechanotransducers, yet their role in gastrulation remains elusive. Here we show that the double knockout of yap and its paralog yap1b in medaka results in an axis assembly failure, due to reduced displacement and migratory persistence in mutant cells. Accordingly, we identified genes involved in cytoskeletal organization and cell-ECM adhesion as potentially direct Yap targets. Dynamic analysis of live sensors and downstream targets reveal that Yap is acting in migratory cells, promoting cortical actin and focal adhesions recruitment. Our results indicate that Yap coordinates a mechanoregulatory program to sustain intracellular tension and maintain the directed cell migration for embryo axis development

    The Al Hoceima 2016 seismic series. Strain partitioning and interaction of structures on a diffuse plate boundary

    Get PDF
    El terremoto principal de la serie sísmica tuvo lugar el 25 de enero de 2016, con una magitud Mw 6.3, que fue precedido por un premonitorio de magnitud Mw 5.1 el día 21 de enero. Hemos utilizado 41 mecanismos focales para analizar las características sismotectónicas y estructurales de la serie. Para agrupar los mecanismo focales hemos utilizado un algoritmo de agrupamiento jerárquico espacial y por el tipo de rotura del mecanismo. De cada agrupación hemos obtenido el mecanismo focal medio y lo hemos asociado a una estructura o familia de estructuras. Hemos comprobado la compatibilidad mecánica de estas estructuras mediante transferencia de esfuerzos de Coulomb. El evento principal de la serie se produjo en la Falla de Al Idrisi intersectando la cresta de Alborán. Este evento disparó réplicas y series independientes en fallas de desgarre asociadas al sistema de Falla de Al Idrisi hacia el sur, pero también en fallas inversas asociadas al levantamiento de la Cresta de Alborán hacia el este; produciendose una partición de la deformación entre ambos tipos de estructuras interaccionando por transferencia de esfuerzos.The mainshock of seismic series took place on January 25, 2016, with a Mw 6.3 magnitude, which was preceded by a premonitory of magnitude Mw 5.1 on 21 January. We have used 41 focal mechanisms to analyze the seismotectonics and the structural characteristics of the series. To cluster the focal mechanisms we used a hierarchical clustering algorithm using the spatial distribution of the events and also the type of rupture mechanism. For each cluster we have obtained the average focal mechanism and have been associated with a structure or family of structures. We have tested the mechanical compatibility of these structures by Coulomb stress transfer modelling. The mainshock of the series occurred in the Al Idrisi Fault intersecting the Alboran Ridge. This event triggered aftershocks and independent series in strike-slip faults associated with the Al Idrisi Fault System towards the south, but also in reverse faults associated with the lifting of the Alboran Ridge eastward; producing a strain partitioning between both types of structures interacting by stress transfer.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEMinisterio de Economía y Competitividad (MINECO)pu

    Role of IL-36 Cytokines in the Regulation of Angiogenesis Potential of Trophoblast Cells

    Get PDF
    IL-36 cytokines (the agonists IL-36α, IL-36β, IL-36γ, and the antagonist IL-36Ra) are expressed in the mouse uterus and associated with maternal immune response during pregnancy. Here, we characterize the expression of IL-36 members in human primary trophoblast cells (PTC) and trophoblastic cell lines (HTR-8/SVneo and JEG-3) and upon treatment with bacterial and viral components. Effects of recombinant IL-36 on the migration capacity of trophoblastic cells, their ability to interact with endothelial cells and the induction of angiogenic factors and miRNAs (angiomiRNAs) were examined. Constitutive protein expression of IL-36 (α, β, and γ) and their receptor (IL-36R) was found in all cell types. In PTC, transcripts for all IL-36 subtypes were found, whereas in trophoblastic cell lines only for IL36G and IL36RN. A synthetic analog of double-stranded RNA (poly I:C) and lipopolysaccharide (LPS) induced the expression of IL-36 members in a cell-specific and time-dependent manner. In HTR-8/SVneo cells, IL-36 cytokines increased cell migration and their capacity to interact with endothelial cells. VEGFA and PGF mRNA and protein, as well as the angiomiRNAs miR-146a-3p and miR-141-5p were upregulated as IL-36 response in PTC and HTR-8/SVneo cells. In conclusion, IL-36 cytokines are modulated by microbial components and regulate trophoblast migration and interaction with endothelial cells. Therefore, a fundamental role of these cytokines in the placentation process and in response to infections may be expected

    Garantismo y crisis de la justicia

    Get PDF
    Esta obra representa una importante reflexión teórica producto de la labor investigativa de sus autores, en torno a uno de los problemas de mayor actualidad en la sociedad contemporánea, cual es, la tensión permanente que se presenta entre la necesidad que tiene el Estado de garantizar un orden o control social y al mismo tiempo, la exigencia actual de la garantía y protección de los derechos fundamentales

    Mutation of vsx genes in zebrafish highlights the robustness of the retinal specification network

    Full text link
    Genetic studies in human and mice have established a dual role for Vsx genes in retina development: an early function in progenitors' specification, and a later requirement for bipolar-cells fate determination. Despite their conserved expression patterns, it is currently unclear to which extent Vsx functions are also conserved across vertebrates, as mutant models are available only in mammals. To gain insight into vsx function in teleosts, we have generated vsx1 and vsx2 CRISPR/Cas9 double knockouts (vsxKO) in zebrafish. Our electrophysiological and histological analyses indicate severe visual impairment and bipolar cells depletion in vsxKO larvae, with retinal precursors being rerouted toward photoreceptor or Müller glia fates. Surprisingly, neural retina is properly specified and maintained in mutant embryos, which do not display microphthalmia. We show that although important cis-regulatory remodelling occurs in vsxKO retinas during early specification, this has little impact at a transcriptomic level. Our observations point to genetic redundancy as an important mechanism sustaining the integrity of the retinal specification network, and to Vsx genes regulatory weight varying substantially among vertebrate species

    Análisis por epigenómica comparativa de elementos cis-reguladores conservados y activos durante el estado filotípico de vertebrados

    Get PDF
    Motivación: Determinar qué fase del desarrollo es más resistente a los cambios evolutivos, y por tanto, está más conservada entre los vertebrados ha sido objeto de debate desde hace años. Existen dos propuestas: el modelo del embudo, que propone que la mayor conservación fenotípica se da durante las etapas más tempranas del desarrollo, y el modelo del reloj de arena, que la establece en el estado filotípico, una etapa intermedia. Aunque se ha demostrado que las formulaciones de éste último son ciertas desde el punto de vista morfológico, la controversia persiste a nivel molecular. El propósito de este proyecto es contribuir a resolver este debate mediante un estudio transcriptómico y epigenómico comparativo en peces cebra y medaka, dos especies separadas evolutivamente varios millones de años.Métodos: Se ha realizado un experimento de RNA-seq de embriones de medaka de 48 hpf (horas post-fertilización) para analizar su transcriptoma y compararlo con el de peces cebra de 24 hpf durante la fase filotípica. También se han llevado a cabo experimentos de ChIP-seq para identificar enhancers conservados y activos en ambas especies durante esa etapa del desarrollo (SPARRs). Se han realizado experimentos de transgénesis por inyección en embriones de pez cebra y medaka en estadio de una célula, transformándolos con plásmidos ZED y SED, respectivamente. Estos vectores contienen algunos de los SPARRs identificados, que se han clonado para controlar la expresión específica de tejido de un gen reportero, con el objetivo de averiguar si su patrón de expresión asociado se conserva en ambas especies.Resultados: El análisis trancriptómico comparativo ha determinado un nivel de expresión similar en la mayoría de genes, exceptuando los que son específicos de tejidos que se desarrollan heterocrónicamente, como el músculo y el tejido nervioso. El estudio epigenómico ha permitido identificar unos 700 SPARRs en ambas especies, que en su mayoría controlan el nivel de expresión de factores de transcripción importantes en el desarrollo, y el experimento de transgénesis ha demostrado que el perfil de actividad de los SPARRs examinados está conservado.Conclusiones: La alta similitud morfológica que caracteriza a embriones de distintas especies de vertebrados en el estado filotípico no sólo se debe a una alta conservación de genes específicos de desarrollo, sino a una conservación de toda la estructura genética de regulación subyacente, que permanece activa en dicha etapa

    Thymidylate synthase gene variants as predictors of clinical response and toxicity to fluoropyrimidine-based chemotherapy for colorectal cancer

    Get PDF
    Abstract Background: Fluoropyrimidines form the chemotherapy backbone of advanced and metastatic colorectal cancer (CRC). These drugs are frequently associated with toxicity events that result in dose adjustments and even suspension of the treatment. The thymidylate synthase (TYMS) gene is a potential marker of response and toxicity to fluoropyirimidines as this enzyme is the molecular target of these drugs. Our aim was to assess the association between variants of TYMS with response and toxicity to fluoropyrimidines in patients with CRC in independent retrospective and prospective studies. Methods: Variants namely rs45445694, rs183205964, rs2853542 and rs151264360 of TYMS were genotyped in 105 CRC patients and were evaluated to define their association with clinical response and toxicity to fluoropyrimidines. Additionally, the relationship between genotypes and tumor gene expression was analyzed by quantitative polymerase chain reaction. Results: The 2R/2R (rs45445694) was associated with clinical response (p = 0.05, odds ratio (OR) = 3.45) and severe toxicity (p = 0.0014, OR = 5.21, from pooled data). Expression analysis in tumor tissues suggested a correlation between the 2R/2R genotype and low TYMS expression. Conclusions: The allele 2R (rs45445694) predicts severe toxicity and objective response in advanced CRC patients. In addition, the alleles G(rs2853542) and 6bp-(rs151264360) are independent predictors of response failure to chemotherapy. This is the first study made on a Latin American population that points out TYMS gene variants have predictive values for response and toxicity in patients with CRC treated with fluoropyrimidine-based chemotherapy

    Grip strength predicts cardiac adverse events in patients with cardiac disorders: an individual patient pooled meta-analysis

    Get PDF
    Objective: Grip strength is a well-characterised measure of weakness and of poor muscle performance, but there is a lack of consensus on its prognostic implications in terms of cardiac adverse events in patients with cardiac disorders. Methods: Articles were searched in PubMed, Cochrane Library, BioMed Central and EMBASE. The main inclusion criteria were patients with cardiac disorders (ischaemic heart disease, heart failure (HF), cardiomyopathies, valvulopathies, arrhythmias); evaluation of grip strength by handheld dynamometer; and relation between grip strength and outcomes. The endpoints of the study were cardiac death, all-cause mortality, hospital admission for HF, cerebrovascular accident (CVA) and myocardial infarction (MI). Data of interest were retrieved from the articles and after contact with authors, and then pooled in an individual patient meta-analysis. Univariate and multivariate logistic regression was performed to define predictors of outcomes. Results: Overall, 23 480 patients were included from 7 studies. The mean age was 62.3±6.9 years and 70% were male. The mean follow-up was 2.82±1.7 years. After multivariate analysis grip strength (difference of 5 kg, 5× kg) emerged as an independent predictor of cardiac death (OR 0.84, 95% CI 0.79 to 0.89, p<0.0001), all-cause death (OR 0.87, 95% CI 0.85 to 0.89, p<0.0001) and hospital admission for HF (OR 0.88, 95% CI 0.84 to 0.92, p<0.0001). On the contrary, we did not find any relationship between grip strength and occurrence of MI or CVA. Conclusion: In patients with cardiac disorders, grip strength predicted cardiac death, all-cause death and hospital admission for HF. Trial registration number: CRD42015025280
    corecore