Meis3 is required for neural crest invasion of the gut during zebrafish enteric nervous system development

During development, vagal neural crest cells fated to contribute to the enteric nervous system migrate ventrally away from the neural tube toward and along the primitive gut. The molecular mechanisms that regulate their early migration en route to and entry into the gut remain elusive. Here, we show that the transcription factor meis3 is expressed along vagal neural crest pathways. Meis3 loss of function results in a reduction in migration efficiency, cell number and the mitotic activity of neural crest cells in the vicinity of the gut, while having no effect on neural crest or gut specification. Later, during enteric nervous system differentiation, Meis3 depleted embryos exhibit colonic aganglionosis, a disorder in which the hindgut is devoid of neurons. Accordingly, the expression of Shh pathway components, previously shown to have a role in the etiology of Hirschsprung's disease, was misregulated within the gut following loss of Meis3. Taken together, these findings support a model in which Meis3 is required for neural crest proliferation, migration into and colonization of the gut such that its loss leads to severe defects in enteric nervous system development

Retinoic acid temporally orchestrates colonization of the gut by vagal neural crest cells

The enteric nervous system arises from neural crest cells that migrate as chains into and along the primitive gut, subsequently differentiating into enteric neurons and glia. Little is known about the mechanisms governing neural crest migration en route to and along the gut in vivo. Here, we report that Retinoic Acid (RA) temporally controls zebrafish enteric neural crest cell chain migration. In vivo imaging reveals that RA loss severely compromises the integrity and migration of the chain of neural crest cells during the window of time window when they are moving along the foregut. After loss of RA, enteric progenitors accumulate in the foregut and differentiate into enteric neurons, but subsequently undergo apoptosis resulting in a striking neuronal deficit. Moreover, ectopic expression of the transcription factor meis3 and/or the receptor ret, partially rescues enteric neuron colonization after RA attenuation. Collectively, our findings suggest that retinoic acid plays a critical temporal role in promoting enteric neural crest chain migration and neuronal survival upstream of Meis3 and RET in vivo

Plantas arom?ticas que vivifican mi ser, la yerbabuena, limoncillo, cidr?n, or?gano y manzanilla

63 P?ginasRecurso Electr?nicoLa sociedad actual frecuentemente se desvincula de los conocimientos te?rico-pr?cticos referentes al empleo de las plantas arom?ticas, olvidando los beneficios en los ?mbitos educativos, familiar y social; como objetivo central se definen estrategias pedag?gicas que favorezcan el reconocimiento y comprensi?n del beneficio con la utilizaci?n de cinco plantas arom?ticas: yerba buena, limoncillo, cidr?n, or?gano y manzanilla, en los estudiantes del CER Socorro de Sabanas del Municipio de Santa Fe de Antioquia y de la I.E. Atanasio Girardot del Municipio de Bello; con Metodolog?a de Investigaci?n Acci?n (IA) considerando los intereses del colectivo frente a la utilizaci?n y beneficios de las plantas arom?ticas, sus efectos curativos, y su empleo en emplastos, bebidas, ba?os, laxantes, entre otros usos. Se cumple con el perfil de la Licenciatura en Educaci?n B?sica establecido por la Universidad del Tolima; se aprecian hallazgos referidos a un grado de concientizaci?n respecto al empleo y uso de las plantas arom?ticas. Result? gratificante para la poblaci?n beneficiaria la adquisici?n de las nociones impartidas, la distribuci?n de macetas y el disfrute de tisanas en cada encuentro para la recolecci?n de informaci?n y socializaci?n final de los resultados. Es gratificante, como evidencia del trabajo y para afianzar los saberes tradicionales, enriquecidos con el enfoque te?rico-pr?ctico de la propuesta, la elaboraci?n y distribuci?n del M?dulo Sembramos la salud. Amerita resaltar la recuperaci?n del patrimonio generado a trav?s de los conversatorios con la comunidad adulta y los educadores de ambas instituciones educativas vinculadas.ABSTRACT. Today's society often split with the theoretical and practical knowledge regarding the use of herbs , forgetting the benefits in education , family and social spheres; like the central objective of teaching strategies that encourage the recognition and understanding of the benefit with the use of five aromatic plants: good grass, lemongrass, Cidr?n , oregano and chamomile in CER students Relief Sheets Municipality of Santa Fe de Antioquia and EI Atanasio Girardot Municipality of Bello ; Research Methodology in Action ( IA ) considering the interests of the collective over the use and benefits of herbs , their healing effects , and their use in plasters, drinks, bathrooms, laxatives, among other uses. It complies with the profile of the Bachelor of Primary Education established by the University of Tolima; findings related to a degree of awareness regarding the employment and use of aromatic plants are appreciated. Gratifying for the acquisition target population received notions, the distribution of pots and enjoys teas at each meeting for the collection of information and socialization of end results. It is gratifying, as evidence of the work and to strengthen traditional knowledge, enriched with theoretical and practical approach of the proposal, development and distribution of sow health module. Amerita highlight the recovery of assets generated through community conversations with adult educators and educational institutions both linked.INTRODUCCI?N 15 1. ANTECEDENTES DEL PROBLEMA 16 1.1. T?TULO DEL TRABAJO 16 2. JUSTIFICACI?N 19 3. FORMULACION DEL PROBLEMA 20 3.1 PREGUNTA MOVILIZADORA 20 3.2 PROBLEMA 20 4. OBJETIVOS 22 4.1 OBJETIVO GENERAL 22 4.2 OBJETIVOS ESPEC?FICOS 22 5. MARCO GENERAL 23 5.2 MARCO CONTEXTUAL 24 5.2.1 Contexto comunitario 24 5.3 COMPONENTE PEDAG?GICO 27 5.3.1 Categor?as generales cultura 27 5.4 COMPONENTE ESPEC?FICO DE ESTUDIO 29 5.4.1 Categor?as espec?ficas 29 5.4.2 Plantas arom?ticas 29 5.4.3 Formas de uso 31 5.4.4 Beneficios 32 5.5 CONSOLIDADO DE LAS PLANTAS OBJETO DE ESTUDIO 32 6. DISE?O METODOL?GICO DEL PROCESO INVESTIGATIVO 40 6.1 POBLACI?N BENEFICIARIA 40 6.2 METODOLOG?A DE TRABAJO 41 6.3 UNIVERSO Y MUESTRA 41 6.4 TIPO DE ESTUDIO 41 6.5 ?REA DE ESTUDIO 42 6.6 PROCEDIMIENTOS DEL DISE?O METODOL?GICO 43 6.7 ESTRATEGIAS DE TRABAJO 43 6.8 INSTRUMENTOS PARA LA RECOLECCI?N DE LA INFORMACI?N 44 7. AN?LISIS DE LA INFORMACI?N 45 7.1 ACTIVIDADES POR DESARROLLAR 45 7.1.1 Etapa inicial 45 7.1.2 Etapa de ejecuci?n 46 7.1.3 Etapa de finalizaci?n 46 8. CRONOGRAMA 47 9. PRESUPUESTO GLOBAL DE LA PROPUESTA 50 10. RECURSOS 53 11. CONCLUSIONES 54 RECOMENDACIONES 55 REFERENCIAS 5

A novel subset of enteric neurons revealed by ptf1a:GFP in the developing zebrafish enteric nervous system

The enteric nervous system, the largest division of the peripheral nervous system, is derived from vagal neural crest cells that invade and populate the entire length of the gut to form diverse neuronal subtypes. Here, we identify a novel population of neurons within the enteric nervous system of zebrafish larvae that express the transgenic marker ptf1a:GFP within the midgut. Genetic lineage analysis reveals that enteric ptf1a:GFP+ cells are derived from the neural crest and that most ptf1a:GFP+ neurons express the neurotransmitter 5HT, demonstrating that they are serotonergic. This transgenic line, Tg(ptf1a:GFP), provides a novel neuronal marker for a subpopulation of neurons within the enteric nervous system, and highlights the possibility that Ptf1a may act as an important transcription factor for enteric neuron development

Midkine-A functions upstream of Id2a to regulate cell cycle kinetics in the developing vertebrate retina

BACKGROUND: Midkine is a small heparin binding growth factor expressed in numerous tissues during development. The unique midkine gene in mammals has two paralogs in zebrafish: midkine-a (mdka) and midkine-b (mdkb). In the zebrafish retina, during both larval development and adult photoreceptor regeneration, mdka is expressed in retinal stem and progenitor cells and functions as a molecular component of the retina’s stem cell niche. In this study, loss-of-function and conditional overexpression were used to investigate the function of Mdka in the retina of the embryonic zebrafish. RESULTS: The results show that during early retinal development Mdka functions to regulate cell cycle kinetics. Following targeted knockdown of Mdka synthesis, retinal progenitors cycle more slowly, and this results in microphthalmia, a diminished rate of cell cycle exit and a temporal delay of cell cycle exit and neuronal differentiation. In contrast, Mdka overexpression results in acceleration of the cell cycle and retinal overgrowth. Mdka gain-of-function, however, does not temporally advance cell cycle exit. Experiments to identify a potential Mdka signaling pathway show that Mdka functions upstream of the HLH regulatory protein, Id2a. Gene expression analysis shows Mdka regulates id2a expression, and co-injection of Mdka morpholinos and id2a mRNA rescues the Mdka loss-of-function phenotype. CONCLUSIONS: These data show that in zebrafish, Mdka resides in a shared Id2a pathway to regulate cell cycle kinetics in retinal progenitors. This is the first study to demonstrate the function of Midkine during retinal development and adds Midkine to the list of growth factors that transcriptionally regulate Id proteins

Tracking neural crest cell cycle progression in vivo

Analysis of cell cycle entry/exit and progression can provide fundamental insights into stem cell propagation, maintenance, and differentiation. The neural crest is a unique stem cell population in vertebrate embryos that undergoes long‐distance collective migration and differentiation into a wide variety of derivatives. Using traditional techniques such as immunohistochemistry to track cell cycle changes in such a dynamic population is challenging, as static time points provide an incomplete spatiotemporal picture. In contrast, the fluorescent, ubiquitination‐based cell cycle indicator (Fucci) system provides in vivo readouts of cell cycle progression and has been previously adapted for use in zebrafish. The most commonly used Fucci systems are ubiquitously expressed, making tracking of a specific cell population challenging. Therefore, we generated a transgenic zebrafish line, Tg(‐4.9sox10:mAG‐gmnn(1/100)‐2A‐mCherry‐cdt1(1/190)), in which the Fucci system is specifically expressed in delaminating and migrating neural crest cells. Here, we demonstrate validation of this new tool and its use in live high‐resolution tracking of cell cycle progression in the neural crest and derivative populations

Tracking neural crest cell cycle progression in vivo

Analysis of cell cycle entry/exit and progression can provide fundamental insights into stem cell propagation, maintenance, and differentiation. The neural crest is a unique stem cell population in vertebrate embryos that undergoes long‐distance collective migration and differentiation into a wide variety of derivatives. Using traditional techniques such as immunohistochemistry to track cell cycle changes in such a dynamic population is challenging, as static time points provide an incomplete spatiotemporal picture. In contrast, the fluorescent, ubiquitination‐based cell cycle indicator (Fucci) system provides in vivo readouts of cell cycle progression and has been previously adapted for use in zebrafish. The most commonly used Fucci systems are ubiquitously expressed, making tracking of a specific cell population challenging. Therefore, we generated a transgenic zebrafish line, Tg(‐4.9sox10:mAG‐gmnn(1/100)‐2A‐mCherry‐cdt1(1/190)), in which the Fucci system is specifically expressed in delaminating and migrating neural crest cells. Here, we demonstrate validation of this new tool and its use in live high‐resolution tracking of cell cycle progression in the neural crest and derivative populations

Retinoic acid temporally orchestrates colonization of the gut by vagal neural crest cells

The enteric nervous system arises from neural crest cells that migrate as chains into and along the primitive gut, subsequently differentiating into enteric neurons and glia. Little is known about the mechanisms governing neural crest migration en route to and along the gut in vivo. Here, we report that Retinoic Acid (RA) temporally controls zebrafish enteric neural crest cell chain migration. In vivo imaging reveals that RA loss severely compromises the integrity and migration of the chain of neural crest cells during the window of time window when they are moving along the foregut. After loss of RA, enteric progenitors accumulate in the foregut and differentiate into enteric neurons, but subsequently undergo apoptosis resulting in a striking neuronal deficit. Moreover, ectopic expression of the transcription factor meis3 and/or the receptor ret, partially rescues enteric neuron colonization after RA attenuation. Collectively, our findings suggest that retinoic acid plays a critical temporal role in promoting enteric neural crest chain migration and neuronal survival upstream of Meis3 and RET in vivo

Young users and the digital divide: readers, participants or creators on Internet?

This article analyses how young people, parents and teachers perceive the uses of digital tools and environments made by those known as digital natives. The research combines analysis of an extensive bibliography on the subject with the results of field research based on 30 focus groups, involving 120 youngsters and 60 adults in five Spanish cities, within the framework of a national study. The results show that while adults consider that young people use technological tools in complex ways directed towards content creation, teenagers perceive themselves as mainly readers and participants on the Net

Migration and Diversification of the Vagal Neural Crest

Arising within the neural tube between the cranial and trunk regions of the body axis, the vagal neural crest shares interesting similarities in its migratory routes and derivatives with other neural crest populations. However, the vagal neural crest is also unique in its ability to contribute to diverse organs including the heart and enteric nervous system. This review highlights the migratory routes of the vagal neural crest and compares them across multiple vertebrates. We also summarize recent advances in understanding vagal neural crest ontogeny and discuss the contribution of this important neural crest population to the cardiovascular system and endoderm-derived organs, including the thymus, lungs and pancreas