In response to extra-cellular cues, cells activate signal transduction pathways to elicit a biological response. Cell surface growth factor receptors such as the Met receptor tyrosine kinase (RTK) activate signals that result in cellular proliferation, survival, migration, as well as epithelial morphogenesis. In order for signal transduction to occur, docking proteins are recruited to the activated RTK, become phosphorylated on tyrosine residues, which then serve as docking sites for the recruitment of other signaling proteins. Docking proteins function to diversify the signal by assembling multi-protein complexes. The Gab1 docking protein is the most tyrosine phosphorylated protein upon Met receptor activation and is required for Met mediated signaling and biology. / Gab1 belongs to a family of docking proteins including the highly related Gab2 protein. Gab1 promotes signals for epithelial morphogenesis downstream of the Met receptor, however Gab2 is unable to do so. Insertion of the Gab1 Met binding Motif (MBM) which confers direct binding to the Met receptor, as well as membrane targeting of Gab2 is sufficient to switch the capacity of Gab2 to activate the morphogenic program, cell scatter and lamellipodia formation. This is achieved via activation of sustained signaling pathways, and redistribution of the Gab protein, and associated molecules to sites of lamellipodia formation at the peripheral edge of the cell. / Activation of the Met RTK, promotes the formation of dorsal ruffles on the apical surface of epithelial cells. The Met receptor, Gab1 and Gab1 associated molecules Shp2, Crk, and p8S subunit of PI3K, are localized to these structures, however only the Gab1erk complex is required to drive dorsal ruffle formation. Gab1 is required for Met induced dorsal ruffles as well as downstream the PDGF and EGF RTKs. These are a signaling micro-environment which results in enhanced receptor degradation. Inhibition or enhancement of Met mediated dorsal ruffle formation correlates with receptor stability. / Dorsal ruffle formation downstream of Met requires the enzymatic activity of PI3K and PLCgamma, both enzymes that metabolize PIP2, and form complexes with Gab1 downstream of Met. PLCgamma and the PIP3 lipid product of PI3K are co-localized with Gab1 in dorsal ruffles. Gab1 engages with elements of the cytoskeleton, actin and cortactin, providing a link between growth factor signaling and remodeling of the actin cytoskeleton. Gab1 is localized to membrane protrusions of the basal surface in organoid cultures and is required for actin protrusions of the basal surface of breast cancer cells.

Dans le but de déterminer le rôle des Rho GTPases et de leurs régulateurs dans les cellules hématopoïétiques, une analyse des niveaux d’expressions de 300 gènes codant pour des protéines impliquées dans les voies de signalisation dépendantes de Rho a été faite à partir d’échantillons de patients atteints de leucémies de type T-ALL. Il a ainsi pu être mis en évidence qu’un groupe de gènes incluant notamment RacGAP1, Ect2, Citron et ARHGAP19 variaient parallèlement. A l’exception de ARHGAP19, ces gènes avaient une fonction connue au cours de la mitose. Il a donc été entrepris de caractériser ARHGAP19 qui, d’après les banques de données, est spécifique du système hématopoïétique, et pour laquelle aucune fonction n’avait encore été déterminée.Afin de déterminer la fonction biologique de GAP19, un anticorps a été généré. Cet outil nous a permis de montrer que l’expression de la protéine est régulée au cours du cycle cellulaire et que sa localisation varie au cours de la mitose. Par ailleurs, nous avons montré que GAP19, joue un rôle essentiel dans le changement de forme des lymphocytes en mitose, la ségrégation des chromatides sœurs et le recrutement membranaire des effecteurs de RhoA au cours de la mitose. Nous avons aussi mis en évidence le mécanisme par lequel GAP19 permet le changement de forme dans les lymphocytes.Nous avons aussi montré que GAP19 est phosphorylée par CDK1 sur deux résidus présents dans la partie C-Terminale. Afin de mettre en évidence le rôle de ces phosphorylations, nous avons généré des cellules Kit225 transfectées avec des plasmides pour les formes non-phosphorylables de la protéine. Ceci nous a permis de mettre en évidence que la phosphorylation des résidus T404 et T476 permet la localisation cytoplasmique de GAP19 en début de mitose. Nous avons aussi pu observer lors de l’anaphase la formation de ponts de chromatines, ainsi qu’une augmentation significative de cellules multinucléées. Par ailleurs, nous avons procédé à des expériences de cytogénétique et d’immunofluorescence afin de déterminer, si les ponts de chromatines avaient pour origine soit des défauts de condensation de la chromatine, soit un stress réplicatif.Enfin, un possible modèle de la protéine ARHGAP19 a été généré et des simulations de dynamiques moléculaires réalisées afin de comprendre le rôle des phosphorylations par CDK1 a un niveau structurel. / In an attempt to understand the role of Rho GTPases and their regulators in hematopoietic cell lines, expression levels of 300 genes were analyzed for proteins involved in Rho dependent signaling pathways from patients with T-ALL leukemia.It was shown that a group of genes consisting of RacGAP1, Ect2 and Citron varied concomitantly. With the exception of ARHGAP19, all already had a known function during mitosis. Consequently, it was decided to characterize ARHGAP19, which according to databases is specific of hematopoietic cell lines, and whose function was unknown. In order to determine the biological function of ARHGAP19, a specific antibody has been generated. This allowed us to demonstrate that the level of expression of the protein vary during the cell cycle and its localization varies during mitosis. In addition, we have shown that ARHGAP19 plays a central role in regulating cell shapes changes, sister chromatids segregation and RhoA effectors membrane recruitment during mitosis. We have also shown that this occurs by a previously undescribed pathway involving RhoA-ROCK-Vimentin.Finally, we have demonstrated that ARHGAP19 is a substrate of CDK1. It is phosphorylated on two residues located in the C-Terminal region of the protein. For investigating the role of these phosphorylations, we have generated Kit225 cell lines transfected with plasmids coding for the non-phosphorylable forms of the protein. This allowed us to show that phosphorylation of residue T404 and T476 are involved preventing GAP19 recruitment at the equatorial cell cortex during mitosis.In addition, we have observed the formation of chromatin bridges, as well as an increase in multinucleated cells. Thus, we have performed cytogenetic experiments for determining if chromatin bridges are due to chromosome condensation defects, or replicative stress. Finally, a possible tertiary structure of ARHGAP19 has been created de novo, and molecular dynamics simulations were generated in order to understand the role of these phosphorylations by CDK1 at a structural level.

No description available.

No description available.

Chondroplasia, the development of cartilage-like characteristics in tendinous tissue, is a form of degeneration found in tendons including those of the rotator cuff. The molecular mechanism of its development is currently unknown. An examination of the features of the torn rotator cuff and the cartilage literature led to the identification of several potential drivers of chondroplasia including cell shape change/actin cytoskeleton and hypoxia. Lovastatin caused actin cytoskeleton disruption and promoted cartilage matrix deposition in the ATDC5 model. It was the most effective member of a panel of cytoskeletal inhibitors, increasing expression of the chondrocytic markers Sox5 and Sox9 and decreasing expression of COL1A1 and COL3A1 in primary human tenocytes. Its effects were dose dependent, reversible by mevalonate addition and long term treatment induced de novo expression of collagen II. Short term hypoxia upregulated VEGF-A and chondrocytic marker gene DEC1 expression but not other chondrocyte markers. Combination treatment with hypoxia did not enhance the effects of lovastatin. These data suggest that modulation of pathways that regulate the actin cytoskeleton and cell shape may alter tenocyte phenotype.

Orientador: Fernanda Miori Pascon / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-26T01:46:29Z (GMT). No. of bitstreams: 1 Joaquim_NataliaMartins_M.pdf: 1245977 bytes, checksum: c5a3811c7ba1d723505963537d831210 (MD5) Previous issue date: 2014 / Resumo: Endodontia em dentes decíduos é um procedimento de suma importância para manter a integridade e saúde dos dentes e tecidos de suporte. Sendo assim, o uso de materiais obturadores de canais radiculares que apresente o máximo de propriedades desejáveis é indispensável. O objetivo do presente estudo foi analisar a citotoxicidade de diferentes materiais obturadores em fibroblastos do ligamento periodontal humano (PDL) e em células osteoblásticas de osteossarcoma humano (Saos-2). Os fibroblastos foram cultivados em meio de cultura (meio Eagle modificado por Dulbeco - DMEM) suplementado com 1% soro fetal bovino (FBS) e antibióticos. Os osteoblastos foram cultivados em meio de cultura McCoy¿s suplementado com 15% FBS e antibióticos. Próximos de atingir a confluência, as células foram plaqueadas na concentração de 7x103 células por poço e foram expostas aos seguintes materiais, conforme os grupos: G1- Meio de cultura sem material obturador (controle negativo), G2- Dimetiilsulfóxido (DMSO) (controle positivo), G3- Calen®, G4- Calen® associada ao Óxido de Zinco, G5- Calen® associada ao Iodofórmio, G6- Óxido de zinco e eugenol (OZE), G7- Vitapex® e G8- UltraCal®XS. A manipulação dos materiais foi realizada em condições assépticas. A citotoxicidade dos materiais obturadores foi analisada em intervalos de tempos (8, 24 e 48 horas) pelo método de redução MTS e classificado como não citotóxico, citotoxicidade leve, moderada e grave. O grupo controle negativo foi composto apenas por células, sem o uso de material obturador. A análise morfológica das células foi realizada por meio da microscopia de fluorescência. Os dados obtidos foram submetidos à análise de variância dois fatores e ao teste Tukey para comparação entre os grupos, com nível de significância 5%. As imagens obtidas por meio da microscopia de fluorescência foram analisadas de forma descritiva. Os resultados mostraram que para os fibroblastos, Calen®(85,91±10,01), Calen® associada ao Óxido de Zinco (85,91±8,16) e Calen® associada ao Iodofórmio (83,96±13,95) diferiram do controle negativo (100±0) e positivo (19.72±5,70) após 8 horas de exposição. Para os osteoblastos, Calen® associada ao Óxido de Zinco (75,87±19,16), Calen® associada ao Iodofórmio (75,5±12,40) e o OZE (68,71±22,19) foram os únicos grupos que em 8 horas diferiram do controle negativo (100±0) e positivo (22,18±6,77). Pode-se concluir que todos os materiais avaliados, para fibroblastos do ligamento periodontal humano, não foram citotóxicos ao longo do tempo. No entanto, Calen® associada ao Iodofórmio apresentou toxicidade leve em 48 horas para os osteoblastos. Vitapex® foi o material que apresentou menor toxicidade celular nos osteoblastos em 8 e 48 horas, comparando-se os outros materiais avaliados. Calen® associado ao Óxido de zinco, Calen® associado ao Iodofórmio e OZE foram capazes de modificar a morfologia dos fibroblastos, mas para os osteoblastos não foram observadas alterações morfológicas / Abstract: Endodontics in primary teeth is an important procedure to maintain the integrity and health of the teeth and supporting tissues. Using a root canal filling material that shows desirable properties is indispensable. The aim of the present study was to evaluate the root filling materials cytotoxicity on periodontal ligament fibroblasts (PDL) and osteoblastic human osteosarcoma cells (Saos-2). Fibroblasts were cultured in culture medium (Dulbeco modified Eagle medium - DMEM) supplemented with 1% fetal bovine serum (FBS) and antibiotics. The osteoblasts were cultured in McCoy's culture medium supplemented with 15% FBS and antibiotics. Next to reach confluence, the cells were plated at a concentration of 7x103 cells per well and were exposed to materials, according to the groups: G1 - culture medium without filling material (negative control); G2- Dimethyl sulfoxide (DMSO) (positive control); G3 ¿ Calen®; G4 - Calen® associated with Zinc Oxide; G5 - Calen® associated with Iodoform; G6 ¿ Zinc Oxide and eugenol (ZOE); G7 - Vitapex®; G8 - UltraCal® XS. The materials were prepared under aseptic conditions. Cytotoxicity was evaluated by cell viability at time intervals (8, 24 and 48 h) by MTS assay and rated as non-cytotoxic, mild, moderate and severe cytotoxicity. The negative control group was composed only of cells without the use of filling material. Cells morphological were observed by fluorescence microscopy. Data were submitted to two-way analysis of variance with post-hoc comparisons base on Tukey's multiple comparisons, with the significance level fixed at 5%. The images obtained at fluorescence microscopy were evaluated using descriptive analysis. The results showed that for fibroblasts, Calen®(85.91±10.01), Calen® associated with Zinc Oxide (85.91±8.16) e Calen® associated with Iodoform (83.96±13.95) was differ from the negative control (100±0) and positive (19.72±5.70), at 8 h. For osteoblasts, Calen® associated with Zinc Oxide (75.87±19.16), Calen® associated with Iodoform (75.5±12.40) and ZOE (68.71±22.19) differed from negative control (100±0) and positive (22.18±6.77) in 8 h. It can be concluded that all materials were non- cytotoxic to human fibroblasts cells over time. However, Calen® + Iodoform showed higher cytotoxicity to osteoblasts at 48 h. Vitapex® was the material that showed the less cell cytotoxicity in osteoblasts at 8 and 48 h, compared to the other materials tested. Calen® associated with Zinc Oxide, Calen® associated with Iodoform and ZOE was able to modify the morphology of fibroblasts, but osteoblasts but no morphologic alterations were observed / Mestrado / Odontopediatria / Mestra em Odontologia

No description available.

Les cellules dans la nature se développent dans un large éventail de formes, suivant divers modèles de croissance. Malgré l'importance de ces processus fondamentaux, la façon dont les cellules régulent leur croissance et leur morphogenèse est encore mal comprise. Dans cette thèse, j'ai exploré ces aspects, avec une approche principalement biomécanique, en concentrant mes investigations sur des cellules à paroi à croissance de pointe et en exploitant en particulier la levure fissipare Schyzosaccharomyces pombe. J'ai d'abord développé de nouvelles méthodes pour mesurer les paramètres mécaniques clés de la paroi cellulaire in vivo et à grande échelle, ce qui a permis les premières observations de la dynamique des parois cellulaires. Ceci a révélé que la paroi cellulaire est plus souple et très variable au niveau des pôles de croissance, et presque stable et plus rigide dans les sites non cultivés. Au cours de l'allongement, il existe une interaction entre la mécanique des parois et la croissance cellulaire, dont le contrôle actif permet l'expansion cellulaire tout en préservant l'intégrité des cellules. De plus, j'ai observé qu'il existe une forte corrélation entre la mécanique des parois cellulaires et la morphologie cellulaire, et des perturbations des propriétés de la paroi affectent directement l'établissement et la maintenance de la forme. Ensemble, mes résultats montrent que la régulation de la paroi est fondamentale dans la détermination de la dynamique cellulaire dans les cellules à parois épaissies. Globalement, cela suggère que l'observation dynamique de la mécanique de surface cellulaire est essentielle pour une compréhension complète des processus multifactoriels et complexes comme la croissance et la morphogenèse. / Cells in nature develop in a wide range of forms, following diverse growth patterns. Despite the importance of these fundamental processes, how cells regulate their growth and morphogenesis is still poorly understood. In this thesis, I explored these processes, focusing my investigations on tip growing walled cells and in particular, by exploiting the fission yeast Schyzosaccharomyces pombe, adopting a mainly biomechanical approach. To this aim, I first developed novel methods to measure key cell wall mechanical parameters in vivo and in large scale, which allowed the very first observations of cell wall dynamics. This revealed that the cell wall is softer and highly variable at growing poles, and almost stable and stiffer at non-growing sites. During elongation, there is an interplay between wall mechanics and cell growth, whose active control allows cell expansion while preserving cell integrity. In addition, I observed that there is a strong correlation between cell wall mechanics and cell morphology, and ectopic perturbations of wall properties directly affect shape establishment and maintenance. Together my results show that the regulation of wall mechanics is fundamental in the determination of cell dynamics in tip growing walled cells. Moreover, this suggests that dynamic observation of cell surface mechanics is crucial for a complete understanding of multifactorial and complex processes as growth and morphogenesis.

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.