Vertebrate development requires the activity of multiple members of the myocyte enhancer factor 2 (mef2) gene family for muscle cell specification and subsequent differentiation. Additionally, it is thought that several muscle-specific functions of MEF2 family proteins require binding additional co-factors including members of the Transcription Enhancing Factor-1 (TEF-1) and Vestigial-like protein families. In Drosophila there is a single mef2 (Dmef2) gene as well single homologues of TEF-1 and vestigial-like; sd and vg, respectively. To help clarify the role(s) of these factors, we examined the requirements for Vg and Sd during Drosophila muscle specification. Analysis of loss of Vg or Sd function mutations confirms that both are required for muscle differentiation, as loss of sd or vg leads to a reproducible loss of a subset of cardiac or somatic muscle cells in developing embryos. However, the requirement for Sd or Vg is cell specific, as over-expression of each of these proteins in other muscle cells also has a deleterious effect on muscle differentiation. Finally, I determined that Sd, Vg and Dmef2 can interact directly. Thus, the muscle specific phenotypes associated with loss or ectopic Vg or Sd expression may be a consequence of alternative binding of Vg and Sd to Dmef2 to form alternative protein complexes that modify Dmef2 activity. The somatic muscles of Drosophila develop in a complex pattern that is repeated in each embryonic hemi-segment. Initial communication between somatic muscles and the epidermal tendon cells is critical for formation of this muscle pattern. However, later establishment of attachments between longitudinal muscles at the segmental borders is largely independent of the muscle-epidermal attachment signals, and relatively little is known about how this event is regulated. Here I show that expression of the transcription factor Vg is required in ventral longitudinal muscles (VL1-4) to make them competent to form stable inter-muscular attachments. Further, the cell-specific differentiation events induced by Vg in two muscles fated to form attachments appear to be coordinated by Drosophila Epidermal Growth Factor (DER) signalling. / Molecular Biology and Genetics

No description available.

Les protéines Vestigial-like constituent une famille de cofacteurs de transcription contenant un domaine très conservé, appelé Tondu, qui permet l’interaction avec les facteurs de transcription de la famille TEAD. L’état de l’art des connaissances actuelles sur cette famille, en termes de répertoire, de structure et de fonction des gènes dans les différents groupes d’animaux, a fait l’objet d’une revue. Durant la thèse, a été étudiée la fonction de deux gènes vestigial, vestigial-like 3 et vestigial-like 4, dans le modèle amphibien xénope. Ce choix découle d’une part, des travaux antérieurs de notre laboratoire qui a caractérisé la famille des gènes vestigial chez le xénope et d’autre part des avantages de ce modèle expérimental qui permet les analyses cellulaires et moléculaires. Les approches de gain et perte de fonction indiquent que vestigial-like 3 est plus particulièrement impliqué dans la migration des cellules de la crête neurale. Vestigial-like 4 a un rôle dans la neurogenèse précoce et la formation de la crête neurale. / Vestigial-like proteins belong to a transcription co factors family with a conserved domain, called tondu, which allows their interaction with TEAD family transcription factors. The state of the art on the current knowledge about this family in terms of gene repertory, structure and functions in different animals has given rise to a review. PhD work has focused on vestigial-like 3 and vestigial-like 4 genes functions in the Xenopus amphibian. This choice stemmed from the laboratory previous works that has described vestigial like gene family in Xenopus, and from the Xenopus model advantages that allows cellular and molecular analysis. Gain and loss of function approaches indicate that vestigial-like 3 is especially implicated in neural crest cells migration. Vestigial-like 4 plays a role in early neurogenesis and neural crest formation.

No description available.

Animal morphogenesis is largely driven by concerted changes in the shape of individual cells. However, how cell shape changes are regulated and coordinated in developing animals is not well understood. Here we show that the two perpendicular signaling gradients of the morphogens Dpp, a TGF-β homologue, and Wingless, a Wnt family member, maintain tissue homoeostasis and control cell shape changes in the developing Drosophila wing. Clones of cells lacking Dpp or Wingless signaling invaginate apically, shorten apico-basally and subsequently extrude basally without disruption of the epithelium. During early larval development, the onset of Dpp and Wingless signaling correlates with the cuboidal-to-columnar cell shape transition of wing disc cells. Gradients in apical-basal length of columnar cells correlate during late larval development with the gradients of Dpp and Wingless signaling activities. Cells receiving high levels of Dpp and Wingless signaling are most elongated and apically constricted. Low levels of Dpp and Wingless signaling correlate with a shorter and apically wider cell morphology. Dpp and Wingless signaling is cell-autonomously required for maintaining the elongated columnar cell shape of late larval wing disc cells. Overactivation of these pathways results in precocious cell elongation during early larval development. These morphogenetic responses to Dpp and Wingless require the transcription factor complexes Mad and Tcf/β-catenin, respectively, indicating that they are mediated by changes in gene expression. The morphogenetic function of Wingless is in part mediated by one of its target genes, the transcription factor Vestigial. Wingless signaling promotes an enrichment of E-cadherin at the adherens junctions, and we show that E-cadherin is required to maintain apical-basal cell length. Dpp signaling controls the subcellular distribution of the activities of the small GTPase Rho1 and the regulatory light chain of non-muscle myosin II (MRLC). Alteration of Rho1 or MRLC activity has a profound effect on apical-basal cell length. Finally, we demonstrate that a decrease in Rho1 or MRLC activity rescues the shortening of cells with compromised Dpp signaling. Our results identify cell-autonomous roles for Dpp and Wingless signaling in promoting and maintaining the elongated columnar shape of wing disc cells. Furthermore, they suggest that Dpp and Wingless signaling control cell shape by regulating the actin-MyosinII/E-cadherin network. / Morphogenese in Tieren wird in hohem Maße von konzertierten Zellformveränderungen einzelner Zellen bewirkt. Es ist jedoch noch nicht hinreichend verstanden, wie Zellformveränderungen in sich entwickelnden Tieren reguliert und koordiniert werden. Hier zeigen wir, dass die zwei zueinander senkrecht stehenden Signalgradienten der Morphogene Dpp, eines TGF-β Homologs, und Wingless, eines Mitglieds der Wnt Familie, im sich entwickelnden Drosophila-Flügel Gewebe-Homöostase aufrechterhalten und Zellformveränderungen kontrollieren. Klone von Zellen, denen Dpp oder Wingless Signalaktivität fehlt, invaginieren von ihrer apikalen Seite her, verkürzen sich in apiko-basaler Richtung und extruieren im Folgenden auf der basalen Seite des Epithels, ohne es zu zerstören. Während der frühen Larvalentwicklung korreliert das Anschalten der Dpp und Wingless Signale mit der Zellformveränderung der Flügelscheibenzellen von kuboidal zu kolumnar. Gradienten in der apiko-basalen Länge von kolumnaren Zellen korrelieren während der späten Larvalentwicklung mit den Gradienten der Dpp und Wingless Signalaktivitäten. Zellen, die hohe Werte an Dpp und Wingless Signalen empfangen, sind am meisten elongiert und apikal konstringiert. Niedrige Werte von Dpp und Wingless Signalen korrelieren mit kürzerer und apikal weiterer Zellmorphologie. Dpp und Wingless Signale werden zellautonom gebraucht für die Aufrechterhaltung der elongierten Zellform von späten larvalen Flügelscheibenzellen. Die Überaktivierung dieser Signalwege führt zu vorzeitiger Zellverlängerung während der frühen Larvalentwicklung. Diese morphogenetischen Antworten auf Dpp und Wingless benötigen die Transkriptionsfaktor-Komplexe Mad beziehungsweise Tcf/β-catenin, was darauf hindeutet, dass sie durch Änderungen in der Genexpression vermittelt werden. Die morphogenetische Funktion von Wingless wird teilweise durch eines seiner Zielgene, Vestigial, vermittelt. Wingless Signale fördern die Anreicherung von E-cadherin an den Adherensverbindungen. Wir zeigen hier, dass E-cadherin gebraucht wird, um apiko-basale Zelllänge aufrechtzuerhalten. Dpp Signale kontrollieren die subzelluläre Verteilung der Aktivitäten der kleinen GTPase Rho1 und der regulatorischen leichten Kette von nicht-muskulärem Myosin II (MRLC). Eine Änderung in der Rho1 oder MRLC Aktivität hat weitreichende Auswirkungen auf die apiko-basale Zelllänge. Schließlich zeigen wir noch, dass eine Verringerung der Rho1 oder MRLC Aktivitäten die Zellverkürzung von Dpp-Signal kompromittierten Zellen rettet. Unsere Resultate identifizieren zellautonome Rollen für Dpp und Wingless Signale in der Förderung und Aufrechterhaltung der elongierten kolumnaren Zellform von Flügelimaginalscheibenzellen. Darüber hinaus suggerieren sie, dass Dpp und Wingless Signale die Zellform durch die Regulierung des Aktin-MyosinII/E-cadherin-Netzwerks kontrollieren.

Animal morphogenesis is largely driven by concerted changes in the shape of individual cells. However, how cell shape changes are regulated and coordinated in developing animals is not well understood. Here we show that the two perpendicular signaling gradients of the morphogens Dpp, a TGF-β homologue, and Wingless, a Wnt family member, maintain tissue homoeostasis and control cell shape changes in the developing Drosophila wing. Clones of cells lacking Dpp or Wingless signaling invaginate apically, shorten apico-basally and subsequently extrude basally without disruption of the epithelium. During early larval development, the onset of Dpp and Wingless signaling correlates with the cuboidal-to-columnar cell shape transition of wing disc cells. Gradients in apical-basal length of columnar cells correlate during late larval development with the gradients of Dpp and Wingless signaling activities. Cells receiving high levels of Dpp and Wingless signaling are most elongated and apically constricted. Low levels of Dpp and Wingless signaling correlate with a shorter and apically wider cell morphology. Dpp and Wingless signaling is cell-autonomously required for maintaining the elongated columnar cell shape of late larval wing disc cells. Overactivation of these pathways results in precocious cell elongation during early larval development. These morphogenetic responses to Dpp and Wingless require the transcription factor complexes Mad and Tcf/β-catenin, respectively, indicating that they are mediated by changes in gene expression. The morphogenetic function of Wingless is in part mediated by one of its target genes, the transcription factor Vestigial. Wingless signaling promotes an enrichment of E-cadherin at the adherens junctions, and we show that E-cadherin is required to maintain apical-basal cell length. Dpp signaling controls the subcellular distribution of the activities of the small GTPase Rho1 and the regulatory light chain of non-muscle myosin II (MRLC). Alteration of Rho1 or MRLC activity has a profound effect on apical-basal cell length. Finally, we demonstrate that a decrease in Rho1 or MRLC activity rescues the shortening of cells with compromised Dpp signaling. Our results identify cell-autonomous roles for Dpp and Wingless signaling in promoting and maintaining the elongated columnar shape of wing disc cells. Furthermore, they suggest that Dpp and Wingless signaling control cell shape by regulating the actin-MyosinII/E-cadherin network. / Morphogenese in Tieren wird in hohem Maße von konzertierten Zellformveränderungen einzelner Zellen bewirkt. Es ist jedoch noch nicht hinreichend verstanden, wie Zellformveränderungen in sich entwickelnden Tieren reguliert und koordiniert werden. Hier zeigen wir, dass die zwei zueinander senkrecht stehenden Signalgradienten der Morphogene Dpp, eines TGF-β Homologs, und Wingless, eines Mitglieds der Wnt Familie, im sich entwickelnden Drosophila-Flügel Gewebe-Homöostase aufrechterhalten und Zellformveränderungen kontrollieren. Klone von Zellen, denen Dpp oder Wingless Signalaktivität fehlt, invaginieren von ihrer apikalen Seite her, verkürzen sich in apiko-basaler Richtung und extruieren im Folgenden auf der basalen Seite des Epithels, ohne es zu zerstören. Während der frühen Larvalentwicklung korreliert das Anschalten der Dpp und Wingless Signale mit der Zellformveränderung der Flügelscheibenzellen von kuboidal zu kolumnar. Gradienten in der apiko-basalen Länge von kolumnaren Zellen korrelieren während der späten Larvalentwicklung mit den Gradienten der Dpp und Wingless Signalaktivitäten. Zellen, die hohe Werte an Dpp und Wingless Signalen empfangen, sind am meisten elongiert und apikal konstringiert. Niedrige Werte von Dpp und Wingless Signalen korrelieren mit kürzerer und apikal weiterer Zellmorphologie. Dpp und Wingless Signale werden zellautonom gebraucht für die Aufrechterhaltung der elongierten Zellform von späten larvalen Flügelscheibenzellen. Die Überaktivierung dieser Signalwege führt zu vorzeitiger Zellverlängerung während der frühen Larvalentwicklung. Diese morphogenetischen Antworten auf Dpp und Wingless benötigen die Transkriptionsfaktor-Komplexe Mad beziehungsweise Tcf/β-catenin, was darauf hindeutet, dass sie durch Änderungen in der Genexpression vermittelt werden. Die morphogenetische Funktion von Wingless wird teilweise durch eines seiner Zielgene, Vestigial, vermittelt. Wingless Signale fördern die Anreicherung von E-cadherin an den Adherensverbindungen. Wir zeigen hier, dass E-cadherin gebraucht wird, um apiko-basale Zelllänge aufrechtzuerhalten. Dpp Signale kontrollieren die subzelluläre Verteilung der Aktivitäten der kleinen GTPase Rho1 und der regulatorischen leichten Kette von nicht-muskulärem Myosin II (MRLC). Eine Änderung in der Rho1 oder MRLC Aktivität hat weitreichende Auswirkungen auf die apiko-basale Zelllänge. Schließlich zeigen wir noch, dass eine Verringerung der Rho1 oder MRLC Aktivitäten die Zellverkürzung von Dpp-Signal kompromittierten Zellen rettet. Unsere Resultate identifizieren zellautonome Rollen für Dpp und Wingless Signale in der Förderung und Aufrechterhaltung der elongierten kolumnaren Zellform von Flügelimaginalscheibenzellen. Darüber hinaus suggerieren sie, dass Dpp und Wingless Signale die Zellform durch die Regulierung des Aktin-MyosinII/E-cadherin-Netzwerks kontrollieren.

Made available in DSpace on 2016-06-02T19:38:52Z (GMT). No. of bitstreams: 1 1667.pdf: 903047 bytes, checksum: 200e210478975256099a0a93897aa338 (MD5) Previous issue date: 2007-02-17 / In this paper I analyze the reading memories narratives of six literacy teachers, teaching in Cycle I (1st to 4th years) of the state education network, in the city council of São Carlos, São Paulo state. As theoretical support, I sought input on studies which dealt with history of life, teacher education, memory and narrative, and the history of reading and literacy. Also with the vestigial paradigm support, I look for trails, signs and signals in their narratives that indicate what their relationship with reading are, not only as teachers, but also as readers, from the past to the present. Data analyzed shows that the teachers are readers of a reading repertoire that is restricted to environmental and/or marginal literacy. (Kleiman, 1998). Taking into consideration that they are responsible for the students reading education, it is concluded that these readings marginal and / or environmental not match with the form of reading to them is required to stimulate in students, most prestigious and valued socially. Their reports also show that the reading past experiences recalling exercise allows a reflection on their pedagogical practice. This school life stories recalling has shown that knowledge is not caught in isolation, and it is possible to find out, through these memory returns, some clues that show, for example, the importance of family and school in the literacy process, and these teachers personal reading conceptions. I believe that on understanding how literacy teachers constitute themselves as readers, it may be possible to think of their reading stories as a starting point or a way in to the expansion of their reading repertoire, aiming to a more equitable distribution of the literate knowledge. / No presente trabalho, analiso as narrativas de memórias de leitura de seis professoras alfabetizadoras, atuantes no Ciclo I (1ª a 4ª séries) da rede estadual de ensino, no município de São Carlos. Para me subsidiar teoricamente, busquei aporte em estudos circunscritos à história de vida e formação docente, memória e narrativa, história da leitura e letramento. Tomando por base o paradigma indiciário, busco em suas narrativas pistas, indícios e sinais que permitam compreender como elas se relacionam com a leitura, como professoras e como leitoras, do passado ao presente. Os dados analisados demonstram que as professoras são leitoras de um repertório de leituras restrito ao letramento ambiental e/ou marginal. (Kleiman, 1998). Levando-se em consideração que elas são as responsáveis pela formação de alunos leitores, conclui-se que essas leituras marginais e/ou ambientais não condizem com a forma de leitura que lhes é exigida desenvolver nos alunos, mais prestigiada e valorizada socialmente. Seus relatos revelam, ainda, que o exercício de rememorar experiências passadas de leitura possibilita uma reflexão sobre sua prática pedagógica. Essa rememoração das histórias de vida escolar mostrou que o conhecimento não é apreendido de forma isolada, sendo possível descobrir, nesses retornos à memória, algumas pistas que evidenciam, por exemplo, a importância da família e da escola no letramento e as concepções pessoais de leitura dessas professoras. Acredito que, compreendendo como as professoras alfabetizadoras se constituem como leitoras, seja possível pensar em suas histórias de leitura como ponto de partida ou via de acesso à ampliação de seu repertório de leituras, visando uma distribuição mais equitativa do saber letrado.

In the age of mass information, globalization, and peer-to-peer social networks, the traditional markers of identity and elective affinities, particularly those of religion and nationalism, are shifting in relation to contemporary trends. The field of Religious Studies has been influenced by a series of ‘post’s: postsecular, postmodern, postcolonial, and post 9/11. The rise of revolutionary religious movements internationally is a hallmark characteristic of the postsecular age. Participants in these movements are variously characterized as religious dissidents, militant secularists, neo-fascist nationalists, and terrorists. However, according to the dialogues within these communities, participants do not think of themselves in these terms. The dualizing labels of ‘religious’ and ‘secular’ do not lend meaning to these contemporary identities. This thesis addresses the question: How do traditional and contemporary theories in the field of Religious Studies evaluate contemporary religious nationalist movements, and how do their analyses compare to how members of the groups in question perceive themselves? To answer this question, this dissertation examines and contrasts four key case studies: the Native Faith Movement and Femen in Ukraine, and the Gezi Park protesters and the Gülen Movement in Turkey. By analyzing group activities through the fora of the curated digital presences of group leaders and members, this research investigates emerging elective affinities and markers of identity which transcend the religious/secular binary. Contemporary theory from the field of Critical Religion and feminist theology transcending the religious/secular binary will be applied to these case studies in order to gain a deeper understanding of the shifting relationships between religion, protest and the nation.

No description available.