Planar cell polarity: the Dachsous/Fat system contributes differently to the embryonic and larval stages of Drosophila.

The epidermal patterns of all three larval instars (L1-L3) ofDrosophilaare made by one unchanging set of cells. The seven rows of cuticular denticles of all larval stages are consistently planar polarised, some pointing forwards, others backwards. In L1 all the predenticles originate at the back of the cells but, in L2 and L3, they form at the front or the back of the cell depending on the polarity of the forthcoming denticles. We find that, to polarise all rows, the Dachsous/Fat system is differentially utilised; in L1 it is active in the placement of the actin-based predenticles but is not crucial for the final orientation of the cuticular denticles, in L2 and L3 it is needed for placement and polarity. We find Four-jointed to be strongly expressed in the tendon cells and show how this might explain the orientation of all seven rows. Unexpectedly, we find that L3 that lack Dachsous differ from larvae lacking Fat and we present evidence that this is due to differently mislocalised Dachs. We make some progress in understanding how Dachs contributes to phenotypes of wildtype and mutant larvae and adults.This work was generously supported by the Wellcome Trust: a Project Grant [086986] and, later, two successive Investigator Awards, [096645 and 107060] awarded to P.A.L., as well as [100986] to D.S. P.S. thanks Fundaçã o para a Ciência e a Tecnologia and the Cambridge Philosophical Society for research studentships.This is the final version of the article. It first appeared from The Company of Biologists via https://doi.org/10.1242/bio.01715

Integrins regulate epithelial cell shape by controlling the architecture and mechanical properties of basal actomyosin networks.

Forces generated by the actomyosin cytoskeleton are key contributors to many morphogenetic processes. The actomyosin cytoskeleton organises in different types of networks depending on intracellular signals and on cell-cell and cell-extracellular matrix (ECM) interactions. However, actomyosin networks are not static and transitions between them have been proposed to drive morphogenesis. Still, little is known about the mechanisms that regulate the dynamics of actomyosin networks during morphogenesis. This work uses the Drosophila follicular epithelium, real-time imaging, laser ablation and quantitative analysis to study the role of integrins on the regulation of basal actomyosin networks organisation and dynamics and the potential contribution of this role to cell shape. We find that elimination of integrins from follicle cells impairs F-actin recruitment to basal medial actomyosin stress fibers. The available F-actin redistributes to the so-called whip-like structures, present at tricellular junctions, and into a new type of actin-rich protrusions that emanate from the basal cortex and project towards the medial region. These F-actin protrusions are dynamic and changes in total protrusion area correlate with periodic cycles of basal myosin accumulation and constriction pulses of the cell membrane. Finally, we find that follicle cells lacking integrin function show increased membrane tension and reduced basal surface. Furthermore, the actin-rich protrusions are responsible for these phenotypes as their elimination in integrin mutant follicle cells rescues both tension and basal surface defects. We thus propose that the role of integrins as regulators of stress fibers plays a key role on controlling epithelial cell shape, as integrin disruption promotes reorganisation into other types of actomyosin networks, in a manner that interferes with proper expansion of epithelial basal surfaces

Dynamics of DNA damage in leukocytes of thoroughbred equines subjected to a standardized excercise test

Esta claramente establecido que durante el ejercicio se produce un aumento en la produccion de radicales libres que pueden romper el equilibrio oxido-reductor y causar dano en el ADN. El objetivo del presente trabajo fue establecer la existencia de dano en el ADN en leucocitos circulantes de equinos sometidos a ejercicio sub-maximo mediante el empleo del ensayo cometa. Se usaron cinco equinos sometidos a un test estandarizado de ejercicio, a los que se les extrajeron muestras antes de comenzar el ejercicio, a los 8,5 m/s, a los 15 m/s, y 1 y 30 min post-ejercicio. Simultaneamente se realizo una ergoespirometria continua para determinar el consumo de oxigeno durante el test de ejercicio. La frecuencia de celulas con dano en el ADN fue 0,448, 0,537, 0,617, 0,556 y 0,592 respectivamente, observandose diferencias significativas con respecto a los valores del tiempo basal (p<0,05). Luego las celulas se clasificaron por niveles de dano, observandose incrementos significativos (p<0,05) especialmente a los 15 m/s y 30 min post-ejercicio. Se observo una asociacion significativa entre la frecuencia de celulas con dano en el ADN y el consumo de oxigeno durante el test estandarizado de ejercicio. Estos resultados sugieren que los factores inductores de dano genotoxico se producen mayoritariamente durante el esfuerzo fisico.It is well established that during exercising, an increase in the production of free radicals occurs, which can break the oxide-reducing balance of the cell causing DNA damage. The aim of this study was to establish the existence of DNA damage in circulating leukocytes of horses undergoing sub-maximal exercise by using the comet assay. Five horses subjected to a standardized exercise test were used. Samples were extracted before starting the exercise and, then, at 8.5 m/s, at 15 m/s, and 1 and 30 min post-exercise. Simultaneously, oxygen consumption during the exercise test was measured. The frequency of cells with DNA damage was 0.448, 0.537, 0.617, 0.556 and 0.592 respectively, being significant the differences from the baseline values over time (p<0.05). Then, the cells were classified by levels of damage, with significant increases (p<0.05), especially at 15 m/s and 30 min after exercise. A significant association between the frequency of cells with DNA damage and oxygen consumption during standardized exercise test is observed. These results suggest that genotoxic damage inducing factors occur mainly during physical exertion.Fil: Muriel, M.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Seoane, Analia Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Savignone, C.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Palacios, A.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Ferreira, V.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Boffi, F. M.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Picco, Sebastian Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin

Barentsz is essential for the posterior localization of oskar mRNA and colocalizes with it to the posterior pole

The localization of Oskar at the posterior pole of the Drosophila oocyte induces the assembly of the pole plasm and therefore defines where the abdomen and germ cells form in the embryo. This localization is achieved by the targeting of oskar mRNA to the posterior and the localized activation of its translation. oskar mRNA seems likely to be actively transported along microtubules, since its localization requires both an intact microtubule cytoskeleton and the plus end–directed motor kinesin I, but nothing is known about how the RNA is coupled to the motor. Here, we describe barentsz, a novel gene required for the localization of oskar mRNA. In contrast to all other mutations that disrupt this process, barentsz-null mutants completely block the posterior localization of oskar mRNA without affecting bicoid and gurken mRNA localization, the organization of the microtubules, or subsequent steps in pole plasm assembly. Surprisingly, most mutant embryos still form an abdomen, indicating that oskar mRNA localization is partially redundant with the translational control. Barentsz protein colocalizes to the posterior with oskar mRNA, and this localization is oskar mRNA dependent. Thus, Barentsz is essential for the posterior localization of oskar mRNA and behaves as a specific component of the oskar RNA transport complex

La competencia tecnológica en los estudiantes de magisterio y su relación con la perspectiva sobre la educación

Las Competencias Tecnológicas respecto a las TIC siguen siendo un elemento clave en la formación de futuros profesionales de la Educación. La situación ha ido variando en el último decenio tanto para los profesores como para los estudiantes en formación inicial como profesores. No obstante, siguen existiendo evidencias sobre algunas carencias respecto a las competencias necesarias para encarar la situación actual y futura. En su formación inicial, lo profesores muestran perfiles estables en su nivel de adquisición de estas competencias. Estos grupos muestran asimismo una relación consistente con las perspectivas sobre la educación, de modo que a mayor nivel de competencia tecnológica se tiene mayor inclinación hacia una enseñanza-aprendizaje basada en una perspectiva constructivista.Technological Competencies in ICT remain a key element in the training of future education professionals. This situation has been changing in the last decade, both for teachers and for students in initial training as teachers. However, there are still evidence of some shortcomings regarding the competences needed to meet the current and future situation. At initial training, teachers show stable profiles in their level of acquisition of these skills. These groups also show a consistent relationship with the perspectives on education, so that a higher level of technological competence have greater inclination towards teaching and learning from a constructivist perspective.Educació

What are the effects of herbivore diversity on tundra ecosystems? : A systematic review protocol

Funding Information: The project was funded by the Icelandic Research Fund (Grant Nr. 217754) and the European Union’s Horizon 2020 programme (CHARTER project, Grant Agreement Nr. 869471). Funding for open access publication was provided by the Agricultural University of Iceland. The funding bodies had no influence in the design of the study and collection, analysis and interpretation of data. Funding Information: This study is a contribution of the Herbivory Network (http://herbivory.lbhi.is), a UArctic Thematic Network. Publisher Copyright: © 2022, The Author(s).Background: Changes in the diversity of herbivore communities can strongly influence the functioning of northern ecosystems. Different herbivores have different impacts on ecosystems because of differences in their diets, behaviour and energy requirements. The combined effects of different herbivores can in some cases compensate each other but lead to stronger directional changes elsewhere. However, the diversity of herbivore assemblages has until recently been a largely overlooked dimension of plant–herbivore interactions. Given the ongoing environmental changes in tundra ecosystems, with increased influx of boreal species and changes in the distribution and abundance of arctic herbivores, a better understanding of the consequences of changes in the diversity of herbivore assemblages is needed. This protocol presents the methodology that will be used in a systematic review on the effects of herbivore diversity on different processes, functions and properties of tundra ecosystems. Methods: This systematic review builds on an earlier systematic map on herbivory studies in the Arctic that identified a relatively large number of studies assessing the effects of multiple herbivores. The systematic review will include primary field studies retrieved from databases, search engines and specialist websites, that compare responses of tundra ecosystems to different levels of herbivore diversity, including both vertebrate and invertebrate herbivores. We will use species richness of herbivores or the richness of functional groups of herbivores as a measure of the diversity of the herbivore assemblages. Studies will be screened in three stages: title, abstract and full text, and inclusion will follow clearly identified eligibility criteria, based on their target population, exposure, comparator and study design. The review will cover terrestrial Arctic ecosystems including the forest-tundra ecotone. Potential outcomes will include multiple processes, functions and properties of tundra ecosystems related to primary productivity, nutrient cycling, accumulation and dynamics of nutrient pools, as well as the impacts of herbivores on other organisms. Studies will be critically appraised for validity, and where studies report similar outcomes, meta-analysis will be performed.Peer reviewe

Exploring the Biological Properties of Zn(II) Bis thiosemicarbazone Helicates

The design of artificial helicoidal molecules derived from metal ions with biological properties is one of the objectives within metallosupramolecular chemistry. Herein, we report three zinc helicates derived from a family of bis thiosemicarbazone ligands with different terminal groups, Zn(L Me)∙2HO 1, Zn(L Ph)∙2HO 2 and Zn(L PhNO2) 3, obtained by an electrochemical methodology. These helicates have been fully characterized by different techniques, including X-ray diffraction. Biological studies of the zinc(II) helicates such as toxicity assays with erythrocytes and interaction studies with proteins and oligonucleotides were performed, demonstrating in all cases low toxicity and an absence of covalent interaction with the proteins and oligonucleotides. The in vitro cytotoxicity of the helicates was tested against MCF-7 (human breast carcinoma), A2780 (human ovarian carcinoma cells), NCI-H460 (human lung carcinoma cells) and MRC-5 (normal human lung fibroblasts), comparing the IC values with cisplatin. We will try to demonstrate if the terminal substituent of the ligand precursor exerts any effect in toxicity or in the antitumor activity of the zinc helicates

La integración de los recursos tecnológicos por parte del profesorado en el aula y su relación con el uso personal-profesional

El proceso de integración de las tecnologías de la información y de la comunicación (TIC) en educación se ha convertido en un proceso lento, como consecuencia de la complejidad del mismo. Uno de los factores clave en la integración de las TIC en la educación es el profesorado, pues sin él, cualquier innovación no se lograría. Para ello, el profesorado ha de gozar de la suficiente confianza que le permita implementar las TIC en el aula, y, por consiguiente, la falta de la misma no represente un serio obstáculo para su integración (BECTA, 2004). Por ello, el profesorado ha de estar capacitado con una serie de conocimientos y habilidades que le permita, por una parte, conocer y dominar los distintos recursos tecnológicos y, por otra, la integración de los mismos en su proceso de enseñanza-aprendizaje. El objetivo de este estudio es analizar las competencias pedagógicas en TIC que posee el profesorado en la educación primaria, educación secundaria obligatoria y bachillerato, y su relación con el uso personal-profesional que hacen de estas tecnologías.Ministerio de Ciencia y Tecnología de EspañaFondo Social Europeo (UE): La formación de los profesores en las TIC como dimensión clave de impacto en el proceso de integración: necesidades, currículo y modelos de formación-innovación.Pedagogí

La competencia pedagógica respecto a las tic en los estudiantes de magisterio y su relación con las estrategias de aprendizaje

Las Tecnologías de la Información y de la Comunicación (TIC) junto con las estrategias de aprendizaje constituyen dos pilares en la universidad. Dentro de las TIC, las Competencias Pedagógicas son un elemento clave en la formación de los estudiantes. Asimismo, las Estrategias de Aprendizaje son centrales para un aprendizaje autorregulado por parte del estudiante. El propósito de este trabajo es establecer relación entre las Competencias Pedagógicas y las Estrategias de Aprendizaje. Para ello se ha utilizado un diseño de encuesta, cuya muestra la constituyen 558 estudiantes de Magisterio de la Universidad Católica de Valencia, utilizándose dos cuestionarios: Innovatic y CEVEAPEU. Los resultados apuntan la existencia de dos grupos en relación con la competencia pedagógica, así como se ha encontrado una relación entre estos dos grupos y las Estrategias de Aprendizaje. Por lo tanto, las universidades han de fomentar las competencias pedagógicas en TIC para incrementar las estrategias de aprendizaje en sus estudiantes, especialmente en aquellos que serán futuros docentes.The Information and Communication Technologies (ICT) along with learning strategies are two pillars in Higher Education. Within ICT, the Pedagogical Competences are a key element in the training of students. Also, Learning Strategies are central to self-regulated learning from the student. The purpose of this paper is to establish relationship between Pedagogical Competences and Learning Strategies. For this we have used a survey design, with a sample of558 students of Teacher at the Universidad Católica de Valencia, using two questionnaires: Innovatic and CEVEAPEU. The results suggest the existence of two groups regarding pedagogical competence and found a relationship between these two groups and Learning Strategies. Therefore, universities should encourage ICT teaching skills to increase learning strategies in their students, especially those who will be future teachers.Educació