RESUMEN
Nitrate is a nutrient and signal that regulates gene expression. The nitrate response has been extensively characterized at the organism, organ, and cell-type-specific levels, but intracellular mRNA dynamics remain unexplored. To characterize nuclear and cytoplasmic transcriptome dynamics in response to nitrate, we performed a time-course expression analysis after nitrate treatment in isolated nuclei, cytoplasm, and whole roots. We identified 402 differentially localized transcripts (DLTs) in response to nitrate treatment. Induced DLT genes showed rapid and transient recruitment of the RNA polymerase II, together with an increase in the mRNA turnover rates. DLTs code for genes involved in metabolic processes, localization, and response to stimulus indicating DLTs include genes with relevant functions for the nitrate response that have not been previously identified. Using single-molecule RNA FISH, we observed early nuclear accumulation of the NITRATE REDUCTASE 1 (NIA1) transcripts in their transcription sites. We found that transcription of NIA1, a gene showing delayed cytoplasmic accumulation, is rapidly and transiently activated; however, its transcripts become unstable when they reach the cytoplasm. Our study reveals the dynamic localization of mRNAs between the nucleus and cytoplasm as an emerging feature in the temporal control of gene expression in response to nitrate treatment in Arabidopsis roots.
RESUMEN
Throughout their lifecycle, plants are subjected to DNA damage from various sources, both environmental and endogenous. Investigating the mechanisms of the DNA damage response (DDR) is essential to unravel how plants adapt to the changing environment, which can induce varying amounts of DNA damage. Using a combination of whole-mount single-molecule RNA fluorescence in situ hybridization (WM-smFISH) and plant cell cycle reporter lines, we investigated the transcriptional activation of a key homologous recombination (HR) gene, RAD51, in response to increasing amounts of DNA damage in Arabidopsis thaliana roots. The results uncover consistent variations in RAD51 transcriptional response and cell cycle arrest among distinct cell types and developmental zones. Furthermore, we demonstrate that DNA damage induced by genotoxic stress results in RAD51 transcription throughout the whole cell cycle, dissociating its traditional link with S/G2 phases. This work advances the current comprehension of DNA damage response in plants by demonstrating quantitative differences in DDR activation. In addition, it reveals new associations with the cell cycle and cell types, providing crucial insights for further studies of the broader response mechanisms in plants.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Ciclo Celular , Daño del ADN , Regulación de la Expresión Génica de las Plantas , Raíces de Plantas , Recombinasa Rad51 , Transcripción Genética , Arabidopsis/genética , Raíces de Plantas/genética , Raíces de Plantas/citología , Ciclo Celular/genética , Recombinasa Rad51/metabolismo , Recombinasa Rad51/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismoRESUMEN
Phosphoramidates are common and widespread backbones of a great variety of fine chemicals, pharmaceuticals, additives and natural products. Conventional approaches to their synthesis make use of toxic chlorinated reagents and intermediates, which are sought to be avoided at an industrial scale. Here we report the coupling of phosphites and amines promoted by a Cu3[Co(CN)6]2-based double metal cyanide heterogeneous catalyst using I2 as additive for the synthesis of phosphoramidates. This strategy successfully provides an efficient, environmentally friendly alternative to the synthesis of these valuable compounds in high yields and it is, to the best of our knowledge, the first heterogeneous approach to this protocol. While the detailed study of the catalyst structure and of the metal centers by PXRD, FTIR, EXAFS and XANES revealed changes in their coordination environment, the catalyst maintained its high activity for at least 5 consecutive iterations of the reaction. Preliminary mechanism studies suggest that the reaction proceeds by a continuous change in the oxidation state of the Cu metal, induced by a O2/I- redox cycle.
RESUMEN
Multicellular organisms result from complex developmental processes largely orchestrated through the quantitative spatiotemporal regulation of gene expression. Yet, obtaining absolute counts of messenger RNAs at a three-dimensional resolution remains challenging, especially in plants, owing to high levels of tissue autofluorescence that prevent the detection of diffraction-limited fluorescent spots. In situ hybridization methods based on amplification cycles have recently emerged, but they are laborious and often lead to quantification biases. In this article, we present a simple method based on single-molecule RNA fluorescence in situ hybridization to visualize and count the number of mRNA molecules in several intact plant tissues. In addition, with the use of fluorescent protein reporters, our method also enables simultaneous detection of mRNA and protein quantity, as well as subcellular distribution, in single cells. With this method, research in plants can now fully explore the benefits of the quantitative analysis of transcription and protein levels at cellular and subcellular resolution in plant tissues.
Asunto(s)
ARN , Hibridación Fluorescente in Situ/métodos , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
Salicylic acid (SA) is a hormone that modulates plant defenses by inducing changes in gene expression. The mechanisms that control SA accumulation are essential for understanding the defensive process. TGA transcription factors from clade II in Arabidopsis, which include the proteins TGA2, TGA5, and TGA6, are known to be key positive mediators for the transcription of genes such as PR-1 that are induced by SA application. However, unexpectedly, stress conditions that induce SA accumulation, such as infection with the avirulent pathogen P. syringae DC3000/AvrRPM1 and UV-C irradiation, result in enhanced PR-1 induction in plants lacking the clade II TGAs (tga256 plants). Increased PR-1 induction was accompanied by enhanced isochorismate synthase-dependent SA production as well as the upregulation of several genes involved in the hormone's accumulation. In response to avirulent P. syringae, PR-1 was previously shown to be controlled by both SA-dependent and -independent pathways. Therefore, the enhanced induction of PR-1 (and other defense genes) and accumulation of SA in the tga256 mutant plants is consistent with the clade II TGA factors providing negative feedback regulation of the SA-dependent and/or -independent pathways. Together, our results indicate that the TGA transcription factors from clade II negatively control SA accumulation under stress conditions that induce the hormone production. Our study describes a mechanism involving old actors playing new roles in regulating SA homeostasis under stress.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Regulación de la Expresión Génica de las Plantas , Hormonas/metabolismo , Mutación , Enfermedades de las Plantas/genética , Pseudomonas syringae , Ácido Salicílico/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Plant cells are surrounded by a cell wall, a rigid structure that is not only important for cell and organ shape, but is also crucial for intercellular communication and interactions with the environment. In the flowering plant Arabidopsis thaliana, the 17 members of the Catharanthus roseus RLK1-like (CrRLK1L) receptor kinase family are involved in a multitude of physiological and developmental processes, making it difficult to assess their primary or ancestral function. To reduce genetic complexity, we characterized the single CrRLK1L gene of Marchantia polymorpha, MpFERONIA (MpFER). Plants with reduced MpFER levels show defects in vegetative development, i.e. rhizoid formation and cell expansion, and have reduced male fertility. In contrast, cell integrity and morphogenesis of the gametophyte are severely affected in Mpfer null mutants and MpFER overexpression lines. Thus, we conclude that the CrRLK1L gene family originated from a single gene with an ancestral function in cell expansion and the maintenance of cellular integrity. During land plant evolution, this ancestral gene diversified to fulfill a multitude of specialized physiological and developmental roles in the formation of both gametophytic and sporophytic structures essential to the life cycle of flowering plants.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Marchantia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Células Germinativas de las Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMEN
The study aimed to analyze the relationship between commitment to the team and team resilience factors (characteristics of resilience and vulnerability under pressure), and to examine whether the task and social intra-group conflict act as mediators between commitment to the team and team resilience factors. One hundred seventy (170) male soccer players (16-38 years; M = 18.35; SD = 4.72) of the national teams of Argentina, Costa Rica, and Mexico participated in the study. The path analytic model was used to test mediating pathways. First, the results revealed that commitment to the team was positively related to characteristics of resilience and negatively to vulnerability under pressure. Second, bootstrap mediation analysis showed that athletes' perceptions of the task and social intra-group conflict mediated the association between their perception of commitment to the team and team resilience factors. Findings provide initial evidence for a link between commitment to the team and team resilience in national teams and also suggest that intra-group conflict can improve the association between commitment to the team and team resilience. Therefore, the main conclusion of this study is that practioners should promote players' commitment to the team and avoid intra-group conflicts within teams to have a resilient team that copes with problems more easily.
RESUMEN
In multicellular organisms, sexual reproduction requires the separation of the germline from the soma. In flowering plants, the female germline precursor differentiates as a single spore mother cell (SMC) as the ovule primordium forms. Here, we explored how organ growth contributes to SMC differentiation. We generated 92 annotated 3D images at cellular resolution in Arabidopsis. We identified the spatio-temporal pattern of cell division that acts in a domain-specific manner as the primordium forms. Tissue growth models uncovered plausible morphogenetic principles involving a spatially confined growth signal, differential mechanical properties, and cell growth anisotropy. Our analysis revealed that SMC characteristics first arise in more than one cell but SMC fate becomes progressively restricted to a single cell during organ growth. Altered primordium geometry coincided with a delay in the fate restriction process in katanin mutants. Altogether, our study suggests that tissue geometry channels reproductive cell fate in the Arabidopsis ovule primordium.
Asunto(s)
Arabidopsis/genética , Arabidopsis/fisiología , División Celular , Óvulo Vegetal/fisiología , Arabidopsis/crecimiento & desarrollo , Ciclo Celular , Diferenciación Celular , Proliferación Celular , Mutación , Óvulo Vegetal/genéticaRESUMEN
Plants possess a robust metabolic network for sensing and controlling reactive oxygen species (ROS) levels upon stress conditions. Evidence shown here supports a role for TGA class II transcription factors as critical regulators of genes controlling ROS levels in the tolerance response to UV-B stress in Arabidopsis. First, tga256 mutant plants showed reduced capacity to scavenge H2O2 and restrict oxidative damage in response to UV-B, and also to methylviologen-induced photooxidative stress. The TGA2 transgene (tga256/TGA2 plants) complemented these phenotypes. Second, RNAseq followed by clustering and Gene Ontology term analyses indicate that TGA2/5/6 positively control the UV-B-induced expression of a group of genes with oxidoreductase, glutathione transferase, and glucosyltransferase activities, such as members of the glutathione S-transferase Tau subfamily (GSTU), which encodes peroxide-scavenging enzymes. Accordingly, increased glutathione peroxidase activity triggered by UV-B was impaired in tga256 mutants. Third, the function of TGA2/5/6 as transcriptional activators of GSTU genes in the UV-B response was confirmed for GSTU7, GSTU8, and GSTU25, using quantitative reverse transcription-PCR and ChIP analyses. Fourth, expression of the GSTU7 transgene complemented the UV-B-susceptible phenotype of tga256 mutant plants. Together, this evidence indicates that TGA2/5/6 factors are key regulators of the antioxidant/detoxifying response to an abiotic stress such as UV-B light overexposure.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Estrés Oxidativo , Factores de Transcripción , Rayos Ultravioleta , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas , Peróxido de Hidrógeno/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Marchantia polymorpha has recently become a prime model for cellular, evo-devo, synthetic biological, and evolutionary investigations. We present a pseudomolecule-scale assembly of the M. polymorpha genome, making comparative genome structure analysis and classical genetic mapping approaches feasible. We anchored 88% of the M. polymorpha draft genome to a high-density linkage map resulting in eight pseudomolecules. We found that the overall genome structure of M. polymorpha is in some respects different from that of the model moss Physcomitrella patens. Specifically, genome collinearity between the two bryophyte genomes and vascular plants is limited, suggesting extensive rearrangements since divergence. Furthermore, recombination rates are greatest in the middle of the chromosome arms in M. polymorpha like in most vascular plant genomes, which is in contrast with P. patens where recombination rates are evenly distributed along the chromosomes. Nevertheless, some other properties of the genome are shared with P. patens. As in P. patens, DNA methylation in M. polymorpha is spread evenly along the chromosomes, which is in stark contrast with the angiosperm model Arabidopsis thaliana, where DNA methylation is strongly enriched at the centromeres. Nevertheless, DNA methylation and recombination rate are anticorrelated in all three species. Finally, M. polymorpha and P. patens centromeres are of similar structure and marked by high abundance of retroelements unlike in vascular plants. Taken together, the highly contiguous genome assembly we present opens unexplored avenues for M. polymorpha research by linking the physical and genetic maps, making novel genomic and genetic analyses, including map-based cloning, feasible.
Asunto(s)
Genoma de Planta/genética , Marchantia/genética , Centrómero/genética , Mapeo Cromosómico/métodos , Cromosomas de las Plantas/genética , Genes de Plantas/genética , Ligamiento Genético , Modelos Genéticos , Recombinación Genética/genética , Secuencias Repetidas en Tándem/genéticaRESUMEN
INTRODUCTION: Introduction: this study presents the results regarding diet and an analysis of natural estrogens (phytoestrogens) intake and how they affect other important aspects, which can modulate biological health functions among university students. Objectives: assessing nutritional habits and estimating the intake of phytoestrogens in the population under study. Materials and methods: Costa Rican female (n: 211, 18.83 ± 2.06 years) and male (n: 199, 19.64 ± 3.05 years) university population of the University of Costa Rica applied anthropometric tests using DEXA, the Food Frequency Questionnaire (FFQ) and the 24-hour Reminder (R-24). Results: the most serious nutritional bad habits were high ingestion of sodium, lipids and animal origin proteins in men and women and a deficit of fiber and folic acid in women. The total intake of phytoestrogens referred to: daidzein 0.23 ± 0.40 mg/day and 7.01 ± 11.94 mg/month in women and 0.17 ± 0.13 mg/day and 5.14 ± 3.96 mg/month in men; mainly consumed in the form of lignans 0.24 ± 0.12 mg/day (women) and 0.23 ± 0.14 mg/day (men). The intake of isoflavones was 0.09 ± 0.38 mg/day (women) and 0.04 ± 0.08 mg/day (men). Conclusions: The study population presented high fat percentage although the consumption of vegetables, cereals, whole grains and fruits tends slightly to be a Mediterranean diet; their food pattern was much closer to the Western diet.
INTRODUCCIÓN: Introducción: este estudio presenta resultados respecto a dieta y un análisis más en profundidad de la exposición a estrógenos naturales (fitoestrógenos) en la ingesta, y como este tipo de compuestos influye y se relaciona con otros aspectos importantes que pueden modular funciones biológicas relacionadas con la salud en estudiantes universitarios. Objetivos: valorar hábitos nutricionales y estimar la ingesta de fitoestrógenos de la población en estudio. Material y métodos: población costarricense universitaria femenina (n: 211, edades 18,83 ± 2,06 años) y masculina (n: 199, edades 19,64 ± 3,05 años) de la Universidad de Costa Rica y se han aplicado pruebas antropométricas mediante el DEXA y cuestionarios de Frecuencia de Consumo de Alimentos (FFQ) y Recuerdos de 24 Horas (R-24). Resultados: los errores nutricionales más graves fueron: la elevada ingesta de sodio, lípidos y proteínas de origen animal en hombres y mujeres, y el déficit importante de fibra y ácido fólico en las mujeres. La ingesta total de fitoestrógenos referidos a la daizdeína fue de 0.23 ± 0.40 mg/día y 7,01 ± 11,94 mg/mes en mujeres y de 0,17 ± 0,13 mg/día y de 5,14 ± 3,96 mg/mes en varones; principalmente consumida en forma de lignanos 0,24 ± 0,12 mg/día (mujeres) y 0,23 ± 0,14 mg/día (hombres), mientras la ingesta de isoflavonas fue de 0,09 ± 0,38 mg/día (mujeres) y de 0,04 ± 0,08 mg/día (hombres). Conclusiones: la población de estudio presentó porcentajes de grasa elevados nutricionalmente hablando, aunque el consumo de vegetales, cereales, granos enteros y frutas tiende un poco a la dieta mediterránea, su patrón alimentario se acerca mucho más a la dieta occidental.
Asunto(s)
Conducta Alimentaria , Fitoestrógenos , Estudiantes , Universidades , Adolescente , Antropometría , Costa Rica , Dieta , Grasas de la Dieta , Femenino , Humanos , Masculino , Evaluación Nutricional , Factores Sexuales , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Resumen Alfaro-Jiménez, D.; Salicetti-Fonseca, A. y Jiménez-Díaz, J. (2018). Efecto del entrenamiento pliométrico en la fuerza explosiva de deportes colectivos: Un metaanálisis. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(1), 1-35. El entrenamiento pliométrico (EPLI) es una herramienta utilizada para mejorar las acciones explosivas en muchos deportes; no obstante, este tipo de entrenamiento no genera el mismo efecto en todos los deportes. El objetivo del estudio fue evaluar el efecto del entrenamiento pliométrico sobre la fuerza explosiva (FE) en los deportes colectivos. En el análisis final, se incluyeron 31 estudios que generaron 50 Tamaños de Efecto (TE). Bajo un modelo de efectos aleatorios, se encontró que el EPLI es efectivo para mejorar la FE (TE=0.98; p=0.00; CI95%=0.77 a 1.20; n=50; Q=174.51; I²=71.95) en deportes de conjunto. Los resultados orientan que para mejorar la FE en este tipo de deportes se debe utilizar el entrenamiento pliométrico sin combinarlo con otro tipo de ejercicios durante al menos diez semanas. Además, este tipo de entrenamiento produce mejorías en la altura de salto, tanto en el periodo preparatorio como en el competitivo, independientemente del tipo de protocolo que se utilice. Se propone realizar estudios confirmatorios con los resultados de este metaanálisis en los que se incluyan otros deportes y se estudie más el tema en mujeres, así como la combinación del EPLI con otro tipo de ejercicios o entrenamientos.
Abstract Alfaro-Jiménez, D.; Salicetti-Fonseca, A. & Jiménez-Díaz, J. (2018). Effect of plyometric training on explosive strength in team sports: A meta-analysis. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(1), 1-35. Plyometric training (EPLI) is used to improve explosive actions in many sports; however, this training does not generate the same effect in all sports. The purpose of the study was to evaluate the effect of plyometric training on explosive strength (FE) in team sports. In the final analysis, 31 studies were included generating 50 Effect Sizes (ES). Under a random effects model, the EPLI was found to be effective in improving FE (ES=0.98, p=0.00, CI95%=0.77 to 1.20, n=50, Q=174.51, I²=71.95) in team sports. Results indicate that, in order to improve FE in this type of sports, plyometric training should be used without combining it with other types of exercises for at least ten weeks. In addition, this training improves jump height in both the preparatory as well as the competitive periods, regardless of the type of protocol used. The results of this meta-analysis should be used in confirmatory studies including other sports. In addition, this topic should be further studied in women, as well as the combination between EPLI with other types of excercises and trainings.
Resumo Alfaro-Jiménez, D.; Salicetti-Fonseca, A. & Jiménez-Díaz, J. (2018). Efeito do treinamento pliométrico na força explosiva de esportes coletivos: Uma meta-análise. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(1), 1-35. O treinamento pliométrico (EPLI) é uma ferramenta utilizada para melhorar as ações explosivas em muitos esportes; não obstante, este tipo de treinamento não gera o mesmo efeito em todos os esportes. O objetivo do estudo foi avaliar o efeito do treinamento pliométrico sobre a força explosiva (FE) nos esportes coletivos. Na análise final, foram incluídos 31 estudos que geraram 50 Tamanhos de Efeito (TE). Sob um modelo de efeitos aleatórios, encontrou-se que o EPLI é efetivo para melhorar a FE (TE=0.98; p=0.00; CI95%=0.77 a 1.20; n=50; Q=174.51; I²=71.95) em esportes coletivos. Os resultados orientam que, para melhorar a FE neste tipo de esportes, é preciso utilizar o treinamento pliométrico sem combiná-lo com outro tipo de exercício durante ao menos dez semanas. Além disso, este tipo de treinamento produz melhorias na altura de salto, tanto no período preparatório quanto no competitivo, independentemente do tipo de protocolo utilizado. Propõe-se realizar estudos confirmatórios com os resultados desta meta-análise nos estudos em que são incluídos outros esportes e mais o tema em mulheres, assim como a combinação do EPLI com outro tipo de exercício ou treinamento.
Asunto(s)
Humanos , Resistencia Física , Ejercicio Físico , Ejercicio Pliométrico , Deportes de Equipo , Entrenamiento de FuerzaRESUMEN
Salicylic acid (SA) is a major defense signal in plants. In Arabidopsis (Arabidopsis thaliana), the chloroplast-localized isochorismate pathway is the main source of SA biosynthesis during abiotic stress or pathogen infections. In the first step of the pathway, the enzyme ISOCHORISMATE SYNTHASE1 (ICS1) converts chorismate to isochorismate. An unknown enzyme subsequently converts isochorismate to SA. Here, we show that ICS1 protein levels increase during UV-C stress. To identify proteins that may play roles in SA production by regulating ICS1, we analyzed proteins that coimmunoprecipitated with ICS1 via mass spectrometry. The ICS1 complexes contained a large number of peptides from the PROHIBITIN (PHB) protein family, with PHB3 the most abundant. PHB proteins have diverse biological functions that include acting as scaffolds for protein complex formation and stabilization. PHB3 was reported previously to localize to mitochondria. Using fractionation, protease protection, and live imaging, we show that PHB3 also localizes to chloroplasts, where ICS1 resides. Notably, loss of PHB3 function led to decreased ICS1 protein levels in response to UV-C stress. However, ICS1 transcript levels remain unchanged, indicating that ICS1 is regulated posttranscriptionally. The phb3 mutant displayed reduced levels of SA, the SA-regulated protein PR1, and hypersensitive cell death in response to UV-C and avirulent strains of Pseudomonas syringae and, correspondingly, supported increased growth of P. syringae The expression of a PHB3 transgene in the phb3 mutant complemented all of these phenotypes. We suggest a model in which the formation of PHB3-ICS1 complexes stabilizes ICS1 to promote SA production in response to stress.
Asunto(s)
Arabidopsis/metabolismo , Transferasas Intramoleculares/metabolismo , Proteínas Represoras/metabolismo , Ácido Salicílico/metabolismo , Arabidopsis/genética , Arabidopsis/microbiología , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cloroplastos/metabolismo , Regulación de la Expresión Génica de las Plantas , Transferasas Intramoleculares/genética , Mitocondrias/metabolismo , Mutación , Plantas Modificadas Genéticamente , Prohibitinas , Pseudomonas syringae/patogenicidad , Proteínas Represoras/genética , Estrés Fisiológico , Rayos UltravioletaRESUMEN
BACKGROUND: In plants, the existence and possible role of epigenetic reprogramming has been questioned because of the occurrence of stably inherited epialleles. Evidence suggests that epigenetic reprogramming does occur during land plant reproduction, but there is little consensus on the generality and extent of epigenetic reprogramming in plants. We studied DNA methylation dynamics during the life cycle of the liverwort Marchantia polymorpha. We isolated thalli and meristems from male and female gametophytes, archegonia, antherozoids, as well as sporophytes at early and late developmental stages, and compared their DNA methylation profiles. RESULTS: Of all cytosines tested for differential DNA methylation, 42% vary significantly in their methylation pattern throughout the life cycle. However, the differences are limited to few comparisons between specific stages of the life cycle and suggest four major epigenetic states specific to sporophytes, vegetative gametophytes, antherozoids, and archegonia. Further analyses indicated clear differences in the mechanisms underlying reprogramming in the gametophytic and sporophytic generations, which are paralleled by differences in the expression of genes involved in DNA methylation. Differentially methylated cytosines with a gain in methylation in antherozoids and archegonia are enriched in the CG and CHG contexts, as well as in gene bodies and gene flanking regions. In contrast, gain of DNA methylation during sporophyte development is mostly limited to the CHH context, LTR retrotransposons, DNA transposons, and repeats. CONCLUSION: We conclude that epigenetic reprogramming occurs at least twice during the life cycle of M. polymorpha and that the underlying mechanisms are likely different between the two events.
Asunto(s)
Epigénesis Genética , Marchantia/genética , Cromosomas de las Plantas , Metilación de ADN , Regulación de la Expresión Génica de las Plantas , Estadios del Ciclo de Vida , Marchantia/crecimiento & desarrollo , Cromosomas SexualesRESUMEN
ResumenPropósito:Conocer la asociación entre algunos factores de riesgo cardiovascular y la presión arterial en reposo de estudiantes universitarios costarricenses.Metodología:una muestra total de 269 estudiantes universitarios (138 varones, 131 mujeres; edad promedio= 19,1 ± 2,8 años) respondieron instrumentos de medición sobre datos demográficos, antecedentes familiares de hipertensión, consumo de alcohol, cantidad de tragos ingeridos semanalmente, hábito de fumar, cantidad de cigarros fumados por día, cantidad de METs de actividad física realizada semanalmente y estado de salud general. Se obtuvo de cada sujeto la presión arterial sistólica (PAs) y diastólica (PAd) en reposo, índice de masa corporal (IMC), índice cintura/cadera (ICC), porcentaje de grasa determinado utilizando el densitómetro óseo (DEXA, marca General Electric) y consumo máximo de oxígeno (VO2max) de forma indirecta. Los datos obtenidos se analizaron mediante Regresión Lineal Múltiple, específicamente aplicando 2 Regresiones de Modelos Lineales Generales (MLG).Resultados:Las variables predictoras incluidas en el modelo explican 28,3% (R2model = 0,283) de la variación en la PAs y un 15,8% (R2model = 0,158) de la variación en la PAd. Los factores que predicen de forma significativa la PAs son Género (p = 0,02) e IMC (p = 0,001) y la PAd es el IMC (p = 0,004). La PAs en reposo, ajustado por la cantidad de cigarros fumados diariamente, la cantidad de tragos consumidos en una semana, el IMC, el ICC, el porcentaje de grasa corporal, el VO2max y la cantidad de METs de actividad física realizados semanalmente, fue 15,8mmHg mayor en hombres en comparación con las mujeres (p = 0,02). Por cada aumento de un kg/m2 en el IMC aumentaron 2,5mmHg y 1,5mmHg la PAs y PAd respectivamente.Conclusión:Al ser el IMC el factor de riesgo modificable, la opción para controlar y retrasar la aparición de hipertensión en jóvenes universitarios, es realizar esfuerzos para mantener un peso saludable en esta población.
AbstractPurpose: The study was designed to determine the association between selected cardiovascular risk factors and resting blood pressure in Costa Rican college students.Methods: Volunteers were 269 students (138 males and 131 females; mean age = 19,1 ± 2,8 yrs.), who completed questionnaires on demographics, family history of hypertension, alcohol intake, quantity of weekly liquor drinks, smoking habits, number of daily cigarettes smoked, physical activity (METs/week), and the general health status. In addition, measurements were obtained on resting systolic (SBP) and diastolic (DBP) blood pressure, body mass index (BMI), waist-to-hip ratio (WHR), percent body fat (% body fat) determined by full-body Dual Energy X-Ray Absorptiometry (DEXA, Lunar Prodigy, General Electric, Madison, WI), and maximum oxygen consumption (VO2max). Multiple regression analysis was used to assess the relationships between the 12 predictor variables using a general lineal model, with both, systolic (SBP) and diastolic (DBP) blood pressure as dependent variables.Results: The predictor variables entered in the model explained 28,3% (R2model = 0,283) of the variance of SBP values and 15,8% (R2model = 0,158) of the variance in DBP values. Gender (p = 0,02) and BMI (p = 0,001) were significant predictors of SBP, and BMI (p = 0,004) was a significant predictor of DBP. The mean SBP adjusted for the number of daily cigarettes smoked, quantity of weekly liquor drinks, BMI, WHR, % body fat, VO2max and METs/week was 15,8 mm Hg higher in males compared to females (p = 0,02). For every increment of 1 kg/m2 in BMI, both, SBP and DBP increased by 2,5 and 1,5 mm Hg, respectively.Conclusions: The modifiable risk factor BMI was associated to changes in both, SBP and DBP, in Costa Rican college students. Serious efforts should be made to achieve a healthy body weight in a population at high risk for hypertension.
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Salud del Estudiante , Capacidad Cardiovascular , Hipertensión/diagnóstico , Estudiantes , Sistema Cardiovascular , Medición de RiesgoRESUMEN
OBJECTIVE: To verify the validity of the body adiposity index (BAI) in a sample of Costa Rican students. METHODS: Volunteers were 93 females (mean age = 18.6 ± 2.4 years) and 106 males (mean age = 19.2 ± 2.8 years). Dual-energy X-ray absorptiometry (DXA) was used as the "gold standard" to determine body fat percentage (BF%). Pearson's correlation coefficient and paired samples t-test studied the association and mean differences between BAI and DXA BF%. Concordance between BAI and DXA BF% was determined by the Lin's concordance correlation coefficient and the Bland-Altman agreement analysis. RESULTS: Significant correlations between BAI and DXA BF% were found for females (r = 0.74) and males (r = 0.53) (P < 0.001). Differences between methods were found for females (BAI = 29.3 ± 4.1% vs. DXA = 36.5 ± 7.9%) and males (BAI = 24.8 ± 3.7% vs. DXA = 21.9 ± 8.6%; P < 0.001). Concordance was poor in females and males. Bland-Altman plots showed BAI underestimating and overestimating BF% in relation to the "gold standard" in females and males, respectively. CONCLUSIONS: BAI presented low agreement with BF% measured by DXA; therefore, BAI is not recommended for BF% prediction in this Central American sample studied. Am. J. Hum. Biol. 28:394-397, 2016. © 2015 Wiley Periodicals, Inc.
Asunto(s)
Adiposidad , Antropometría/métodos , Estudiantes/estadística & datos numéricos , Absorciometría de Fotón , Adolescente , Costa Rica , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
Encephalocele represents one end of the spectrum of open neural tube defects. We report an infant with Chiari type 3 malformation manifesting as infratorcular occipital meningoencephalocele with dermoid cyst. To our knowledge, this is the first time that this association is described. The pathogenesis, surgical treatment, prognosis and management difficulties are also being discussed.