RESUMO
Zebrafish are able to regenerate the spinal cord and recover motor and sensory functions upon severe injury, through the activation of cells located at the ependymal canal. Here, we show that cells surrounding the ependymal canal in the adult zebrafish spinal cord express Foxj1a. We demonstrate that ependymal cells express Foxj1a from their birth in the embryonic neural tube and that Foxj1a activity is required for the final positioning of the ependymal canal. We also show that in response to spinal cord injury, Foxj1a ependymal cells actively proliferate and contribute to the restoration of the spinal cord structure. Finally, this study reveals that Foxj1a expression in the injured spinal cord is regulated by regulatory elements activated during regeneration. These data establish Foxj1a as a pan-ependymal marker in development, homeostasis and regeneration and may help identify the signals that enable this progenitor population to replace lost cells after spinal cord injury.
Assuntos
Epêndima/fisiologia , Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica no Desenvolvimento , Regeneração , Peixe-Zebra/fisiologia , Animais , Animais Geneticamente Modificados , Epêndima/citologia , Epêndima/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Microscopia Eletrônica de Transmissão , RNA Mensageiro/genética , Traumatismos da Medula Espinal/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/lesões , Proteínas de Peixe-ZebraRESUMO
Social and Emotional Learning (SEL) is an educational movement that is gaining ground throughout the world. We can define SEL as the capacity to recognize and manage emotions, solve problems effectively, and establish positive relationships with others. Research has demonstrated the significant role of SEL in promoting healthy student development and academic achievement. Extensive research confirms that SEL competencies: can be taught, that they promote positive development and reduce problem behaviors, and that they improve students' academic achievement and citizenship. At the international level, several rigorous studies have identified programs and practices that promote SEL. In Portugal, however, no review has yet been published regarding the implementation of SEL programs. Such a study would elucidate the current panorama of SEL programs in Portugal. This study aims to identify research on SEL programs implemented in Portuguese schools and the relationship of those programs with academic achievement. To this end, we have consulted the following databases: Scientific Repository of Open Access of Portugal (RCAAP), Online Knowledge Library (b-on), and Web of Science (WoS). The criteria were: (a) all time frames; (b) publications in either Portuguese or English; (c) programs that developed socio-emotional competencies in Portuguese schools; (d) academic levels including elementary, middle, and high school and (e) students of regular education. Few publications on SEL programs implemented in Portugal were found, although the recent decade has witnessed an upsurge of interest in the topic, principally that arising from academic research.
RESUMO
The stereotypic left-right (LR) asymmetric distribution of internal organs is due to an asymmetric molecular cascade in the lateral plate mesoderm (LPM) that is originated at the embryonic node. In chicken embryos, molecular asymmetries at Hensen's node are created by leftward cell movements that occur transiently. What terminates these movements, and, moreover, what is the impact of prolonging them on the LR asymmetry cascade? We show that leftward movements last longer when N-cadherin function is blocked and cease prematurely when N-cadherin is overexpressed on the right side of the node. The prolonged leftward movements lead to loss of asymmetric expression of fgf8 and nodal at the node region. This originates an abnormal expression of the asymmetric genes cer1 and snai1 in the LPM, resulting in mispositioned hearts. We conclude that N-cadherin stops the leftward cell movements and that this termination is an essential step in the establishment of LR asymmetry.