Cette thèse vise l’élaboration d’un cadre d’analyse des conduites motrices des élèves engagés dans une tâche motrice en EPS. Cet objectif s’ancre dans le constat d’un déficit de connaissances des enseignants d’EPS en matière de lecture de la motricité des élèves et de guidage de leurs apprentissages. En appui sur le constat que les enseignants experts perçoivent les conduites motrices des élèves indissociablement comme forme et sens, le cadre de la Gestalttheorie a été retenu pour considérer ces conduites comme des totalités dynamiques et signifiantes. L’ancrage phénoménologique de la Gestalttheorie a conduit à recueillir deux types de données empiriques sur le terrain de l’enseignement de trois APSA (gymnastique, natation et danse) : a) des données descriptives de type morphologique, relatives aux formes de corps et de mouvements corporels donnés à voir par les élèves ; b) des données interprétatives relatives à leur expérience vécue, obtenues, d’une part, en faisant des inférences sur le sens de cette expérience à partir des formes observées et, d’autre part, en utilisant la rétroaction vidéo dans l’esprit de l’explicitation psychophénoménologique pour conduire des entretiens avec les participants. Le traitement des données a permis de faire émerger des catégories fonctionnelles de la motricité de deux ordres : des catégories infraintentionnelles et des catégories intentionnelles. Le « remplissement » de ces catégories au fil des trois études présentées, ainsi que leur mise en relation dans la structure d’ensemble que représente la conduite motrice comme gestalt, ont permis d’établir une lecture compréhensive de l’organisation motrice des participants et de mettre en évidence la cohérence de « comportements privilégiés », c’est-à-dire des conduites motrices momentanément adossées certes à un certain « vouloir », mais indissociablement à un certain « pouvoir » actuels. Les résultats montrent qu’avec l’augmentation du degré d’élaboration de l’organisation motrice, les différentes fonctions considérées pour l’analyse s’intègrent de plus en plus dans une unité fonctionnelle fédérée par une visée intentionnelle polarisée par la finalité de l’action. La synthèse des résultats montre la possibilité de baliser des éléments d’une morphogenèse des conduites motrices, dont un aspect générique saillant converge avec le principe de concrétisation énoncé par Simondon à propos des objets techniques en général. / This thesis aims to elaborate an analytical framework of pupil motor skills when takingpart in motor skills tasks in a Physical Education class. The fundamental reasoning behind thisstudy is the observation of a general lack of understanding among P.E. teachers of how tointerpret pupils’ motor skills and how to best guide pupils’ learning. Considering also theobservation that specialist Physical Education teachers perceive pupils’ motor skills as aninseparable item in both form and meaning, the Gestalttheory framework has been used toconsider these skills as dynamic and meaningful totalities. The phenomenological basis ofGestalt theory led us to collect two sorts of empirical data in fieldwork when teaching threeactivities (gymnastics, swimming and dance): a) descriptive data of a morphological type,relative to the corporeal forms and body movement made by the pupils ; b) interpretive datarelative to their actual experiences, obtained, on the one hand, by making inferences tomeaning of these experiences based on the forms observed and, on the other hand, by usingvideo replays as in a psycho-phenomenological explication to conduct interviews with theparticipants.The processing of this data allowed us to show the existence of two functional categoriesof motor skills : infra-intentional and intentional categories. The “completion” of thesecategories during the three studies mentioned, as well as the connection with the overallstructure which shows motor skills as essentially Gestalt, enabled us to establishcomprehensive understanding of the participants’ motor organisation and to underline thecoherence of “privileged behaviour”, in other words motor skills linked, be it momentarily, toa certain current “desire” but also inseparable from a certain current “ability”. The resultsshow that as the degree of elaboration of motor skills increases, the different functions studiedare constantly integrated into a functional unit mobilised by focalising an intention polarisedby the final result of the action. The synthesis of the results gives us the possibility to markout the elements of motor skills morphogenesis, whose most salient generic aspect is theconvergence with the principle of concretisation as stated by Simondon in reference totechnical objects in general.

Introdução: As glândulas salivares humanas passam por diversos e complexos processos durante o período de desenvolvimento, até que adquiram maturidade estrutural para desempenhar sua função, a formação e secreção de saliva. Considerada essencial à saúde e homeostase da cavidade oral, a saliva é um fluido aquoso que depende de um mecanismo de transporte entre as membranas celulares por meio das aquaporinas. A família de proteínas aquaporinas possui treze membros. Somente algumas dessas proteínas atuam nas glândulas salivares formando poros na bicamada lipídica das membranas celulares facilitando o transporte de água e pequenos solutos, cruciais à regulação da qualidade e quantidade de saliva secretada. Proposição: Diante deste cenário, avaliamos por meio da técnica de imunoistoquímica o padrão de expressão das aquaporinas 1, 3 e 5 de glândulas salivares em desenvolvimento, com o intuito de contribuir com informações de base para futuras pesquisas. Metodologia: 47 espécimes parafinados de glândulas salivares em desenvolvimento, de diferentes sítios da cavidade oral de 20 fetos humanos, com idade entre 14 e 25 semanas, foram submetidos à técnica de imunoperoxidase. Os resultados foram analisados, de acordo com o estágio da morfogênese glandular e localização da expressão das aquaporinas. Resultados: Na fase de botão, houve a expressão das aquaporinas 1, 3 e 5 em todas as células epiteliais; na fase pseudoglandular, a expressão dessas proteínas foi vista nos ductos rudimentares (com exceção da aquaporina 1) e nas porções terminais (futuros ácinos); na fase canalicular as aquaporinas foram principalmente detectadas nos ácinos rudimentares e ductos. Finalmente, na fase de botão terminal, as aquaporinas 3 e 5 foram detectadas nas membranas das células acinares e os ductos expressaram todas as aquaporinas. Conclusão: O presente trabalho evidenciou a imunoexpressão das aquaporinas 1, 3 e 5 nas glândulas salivares humanas durante o período de embriogênese. A análise topográfica dessas proteínas nos permitiu identificar diferenças no padrão de expressão entre as diferentes regiões estruturais e estágios do desenvolvimento glandular, sugerindo diferentes papéis para cada proteína / Introduction: The human salivary glands morphogenesis depends on complex processes during the development period until they reach full structural maturity to perform its function - the synthesis and secretion of saliva. The saliva is a complex aqueous fluid considered essential to health and homeostasis of the oral cavity; its synthesis depends on several molecular mechanisms, including the transport of water, solutes, ions, amongst others across the cell membranes. The aquaporin family of proteins is essential in this process. This protein family consists of thirteen members that form channels across the cell membrane facilitating water and small solutes transportation, crucial to the regulation of quality and quantity of secreted saliva. Aims: In this scenario, we evaluated, using the immunohistochemistry technique, the expression pattern of aquaporins 1, 3 and 5 in the different phases of salivary glands development, in order to understand the role of these protein in the formation of human salivary gland morphogenesis. Methodology: 47 specimens of paraffin embedded human salivary glands at various developmental phases were included in the study. The specimens were derived from various sites of the oral cavity of 20 human fetuses aged between 14 and 25 weeks of gestation. All specimens were subjected to the imunohistochemical immunoperoxidase technique. The results were qualitatively and semiquantitatively analyzed according to the stage of glandular morphogenesis and express location of aquaporin. Results: In the bud stage, there was expression of aquaporin 1, 3 and 5 in all glandular epithelial cells; in pseudoglandular stage, the expression of these proteins was seen in rudimentary ducts (except aquaporin-1) and the terminal end buds (future acini); in the canalicular phase the aquaporins were mainly detected in the rudimentary ducts and acini. Finally, in terminal bud stage, the aquaporin 3 and 5 were detected in the membranes of the ducts and acinar cells expressed all aquaporins. Conclusion: This study showed the presence of aquaporins 1, 3 and 5 in human salivary glands during embryogenesis period. The topographic analysis of these proteins allowed us to identify differences in the expression pattern between the different structural regions and stages of glandular development, suggesting different roles for each of these proteins

A natureza e a magnitude das respostas morfogênicas em plantas forrageiras variam com a disponibilidade de fatores climáticos de crescimento e com as metas de manejo utilizadas, modificando as características estruturais do dossel forrageiro. Nesse cenário, intensidades de desfolhação determinam alterações de forma e função nas plantas forrageiras que, por sua vez, definem e caracterizam estratégias de crescimento e perenização e a resistência das plantas ao pastejo. O objetivo deste estudo foi descrever e caracterizar as respostas morfogênicas e as características morfológicas do amendoim forrageiro (Arachis pintoi cv. Belmonte) submetido a intensidades de pastejo sob lotação contínua de janeiro de 2013 a março de 2014. Os tratamentos corresponderam a quatro níveis de intensidade de pastejo (severo - S, moderado - M, leniente - L, e muito leniente - ML) representados pelas alturas de pasto de 5, 10, 15 e 20 cm, e foram alocados às unidades experimentais (piquetes de 210 m2) segundo um delineamento de blocos completos casualizados, com 4 repetições. Foram identificados dez estágios de desenvolvimento das folhas de amendoim forrageiro que foram utilizados como referência para a realização das avaliações das respostas morfogênicas. Os folíolos apresentaram simetria dentro dos pares, não havendo a necessidade de mensuração dos quatro folíolos, apenas de um dos folíolos de cada par. A relação relativamente estável entre comprimento e largura dos folíolos permitiu que a área foliar fosse calculada de forma direta desde que um fator de correção (0,71) para a forma elíptica dos folíolos fosse utilizado. Estratégias distintas de crescimento foram utilizadas pelo amendoim forrageiro ao longo do ano. Estas foram caracterizadas por uma relação inversa entre as variáveis indicadoras de tamanho das plantas (comprimento do estolão, comprimento médio entre nós, entre pontos de crescimento e de enraizamento) e aquelas indicadoras de número de indivíduos (densidade de estolões, de nós, de pontos de crescimento e de pontos de enraizamento), com as maiores diferenças registradas nos pastos submetidos aos tratamentos L e VL. De forma geral, o aumento nas variáveis indicadoras de tamanho esteve associado com a diminuição daquelas indicadoras de número de indivíduos. Essa relação parece descrever um processo de segmentação das plantas caracterizado pela formação de unidades menores e autônomas durante o outono que voltam a aumentar de tamanho durante a primavera e verão. Esse processo viabiliza a reprodução clonal das plantas e contribui para a persistência da espécie na área. Pastos submetidos aos tratamentos S e M apresentaram maior taxa de aparecimento de folhas, menor filocrono e menor tamanho final de folhas que pastos submetidos aos tratamentos L e ML. Esse padrão de crescimento resultou em valores relativamente estáveis de IAF para as intensidades de pastejo. O IAF dos pastos variou apenas com a época do ano, refletindo a estacionalidade natural de crescimento das plantas. O amendoim forrageiro apresenta elevada plasticidade fenotípica e capacidade de adaptação ao pastejo, mas é preciso evitar estresses que possam interromper o processo de segmentação durante o outono, uma vez que isso poderia interferir com a perenização das plantas e favorecer o início de processo de degradação da área. / The nature and the magnitude of morphogenetic responses of forage plants vary with the availability of climatic growth factors and with management targets, modifying sward structural characteristics. In this context, defoliation intensity determines changes in plant form and function, which, in turn, define and characterise growth and perennation mechanisms and plant resistance to grazing. The objective of this study was to describe and characterise morphogenetic responses and morphological characteristics of forage peanut (Arachis pintoi cv. Belmonte) subjected to grazing intensities under continuous stocking from January 2013 to March 2014. Treatments corresponded to four levels of grazing intensity (severe - S, moderate - M, lenient - L, and very lenient - VL) represented by the sward management heights of 5, 10, 15 and 20 cm, and were allocated to experimental units (210 m2 paddocks) according to a complete randomised block design with four replications. Ten stages of leaf development were identified and used as reference for evaluations of plant morphogenetic responses. Leaflets were symmetrical within pairs, indicating the possibility of measuring leaf expansion in just one leaflet of each pair. The relatively stable leaflet length:width ratio allowed direct calculations of leaf area since a correction factor (0.71) for the elliptical form of the leaflets was used. Forage peanut used different growth mechanisms throughout the year. These were characterised by an inverse relationship between plant size (stolon length, internode length, distance between growing points and between rooting points) and plant number (stolon density, node density, growing point density and rooting point density), with greater differences recorded on swards subjected to treatments L and VL. In general, the increase in plant size was associated with a reduction in plant number. This relationship seems to describe a plant segmentation process that results in small autonomous units during autumn, that increase again in size during spring and summer. This process ensures plant clonal reproduction and favours persistence. Swards subjected to treatments S and M showed higher rates if leaf appearance, smaller phyllochron and smaller leaves than swards subjected to treatments L and VL. This resulted in LAI values relatively stable across treatments. LAI values varied only with season of the year, reflecting the seasonality of plant growth. Forage peanut is highly phenotypically plasticand adaptated to grazing, but stresses may interrupt the segmentation process during autumn, and this may interfere with plant perennation and favour the beginning of a degradation process.

Le travail présenté dans ce manuscrit est l'aboutissement de trois différents projets sur le couplage entre la mécanique et la croissance. Le premier chapitre est une revue concernant la mécanique et l'élongation des cellules à parois, où l'accent est placé sur les travaux numériques. Le deuxième chapitre présente quelques modèles de la mécanique du développement avec plus de détails techniques. Le troisième chapitre est une étude de l'établissement et de la stabilisation de la polarité chez les spores de la levure à fission, un phénomène qui repose sur un couplage entre mécanique, polarité, et croissance. Le quatrième chapitre est une étude numérique d'un modèle chimio-mécanique de phyllotaxie chez les plantes. Les motifs d'hormone de croissance sont créés par l'intermédiaire d'une rétro-action entre la mécanique des cellules et le transport polaire de cette hormone. Nous nous sommes demandé si le champ à l'origine de la rétro-action est la déformation ou la contrainte, une question ignorée dans la plupart des travaux sur le couplage entre mécanique et biochimie. Le cinquième chapitre concerne aussi un couplage entre polarité et mécanique. Nous étudions la manière dont la contrainte générée par la croissance ou la courbure des tissus peut se substituer aux indications géométriques qui orientent les divisions cellulaires à l'apex de la tige. / The work presented here is the result of three different projects about the coupling of mechanics and growth. The first chapter is a review about mechanics and elongation of walled cells, focused on the computational studies. The second chapter presents some models of the mechanics of development with more technical details. The third chapter is a study of the establishment and stabilization of polarity in fission yeast spores, a phenomenon that relies on a coupling between mechanics, polarity, and growth. The fourth chapter is the computational study of a chemomechanical model of plant phyllotaxis. Patterns of growth hormone are achieved thanks to a feedback with cell mechanics and polar transport. We focused our attention on the question of stress- or strain-sensing, ignored in most other studies of the interaction between biochemistry and mechanics. The fifth chapter is also about a coupling between polarity and mechanics. We investigate how the mechanical stress generated by growth or curvature of the tissues can override the geometrical cues to orient the cell divisions in the shoot apical meristem.

O estudo da morfogênese e da dinâmica de acúmulo de forragem possibilita melhor entendimento dos processos fisiológicos da planta em resposta a práticas de manejo empregadas. O presente estudo foi conduzido em uma área pertencente ao Departamento de Zootecnia da ESALQ/USP, estabelecida com o capim-xaraés [Brachiaria brizantha (Hochst ex A. RICH) STAPF. cv. Xaraés], durante o verão agrostológico de 2006/2007. O objetivo do estudo foi comparar as respostas morfogênicas e estruturais do capim-xaraés submetido a estratégias de pastejo rotativo em janelas temporais pré-estabelecidas, perfazendo um verão agrostológico, para estabelecer possíveis contrastes nas respostas dessa espécie a intervalos de rebrotação variáveis. O experimento envolveu três tratamentos baseados em intervalo de pastejo: a cada 28 dias ou sempre que a interceptação de luz (IL) pelo dossel forrageiro atingisse 95% ou 100% durante a rebrotação. O delineamento experimental utilizado foi o completamente casualizado, com três repetições. Os dados foram coletados em três momentos durante o verão agrostológico, correspondentes aos meses de Out/Nov, Dez/Jan e Fev/Mar. Foram avaliadas as seguintes variáveis-reposta: densidade populacional de perfilhos (DPP) aéreos e basais, altura do dossel, massa de forragem, relação folha:colmo pré-pastejo (F:C), índice de área da folhagem (IAFo), taxa de alongamento de folhas (TAlF), taxa de senescência de folhas (TSeF), taxa de alongamento de colmos (TAlC), comprimento final da folha (CFF), comprimento do colmo (colmo + pseudo-colmo) (CC), número de folhas vivas por perfilho (NFV), filocrono (Fil), duração de vida da folha (DVF) e taxa de crescimento de folhas (TCF). O tratamento 100% IL resultou nos maiores valores de massa de forragem pré- (5200 kg ha-1 MS) e pós-pastejo (1330 kg ha-1 MS), assim como no maior acúmulo médio de forragem (3870 kg ha-1 MS). O tratamento de 28 dias resultou em níveis variáveis de IL pré-pastejo, embora, na média, tenha sido semelhante ao tratamento 95% IL. O tratamento 95% IL e o 28 dias resultaram nos menores valores de IAFo pré-pastejo (3,62 e 3,75, respectivamente), mas os maiores IAFos pós-pastejo. A relação F:C não variou entre os tratamentos, assim como a DPP aéreos e total. O tratamento 100% IL gerou a menor DPP basal (1189 perfilhos m-2) e o tratamento 95% IL a maior (1260 perfilhos m-2). Não houve diferença entre os tratamentos para a TApF, Fil, DVF e NFV nas épocas avaliadas. O tratamento 100% IL resultou nos maiores valores de CFF e TCF e 95% IL nos menores. Conclui-se que o uso da IL como indicador do momento de interrupção da rebrotação e início do pastejo resulta em variações no comprimento do período de descanso em pastos sob lotação intermitente. Além disso, fica evidente que o componente colmo é o principal responsável pelas altas taxas de acúmulo de forragem de gramíneas tropicais em situações de períodos prolongados de descanso. Estudos que estabeleçam padrões de idades fisiológicas podem explicar melhor os contrastes existentes entre tratamentos cujos intervalos de pastejo se baseiam em níveis de interceptação luminosa pelo dossel forrageiro durante a rebrotação. / The study of morphogenesis and the dynamics of forage accumulation allows for a better understanding of plant physiological processes in response to management practices. This study was conducted in Piracicaba, SP, on a pasture established with Xaraés palisadegrass [Brachiaria brizantha (Hochst ex A. Rich) Stapf. cv. Xaraés], during the summer growing season of 2006/2007. The objective was to compare the structural and morphogenic responses of this forage grass subjected to intermittent defoliation strategies during the summer growing season, and try to establish possible contrasts in the responses of this species to varying regrowth intervals. Treatments were three grazing frequencies applied as rest periods: grazing every 28 days or when the light interception (LI) by sward reached 95% or 100% during the regrowth. The experimental design was completely randomized, with three replications. Data were collected and then divided into three portions of the growing season, corresponding to the months of Oct/Nov, Dec/Jan and Feb/Mar. The following responses were measured: tiller (basal and aerial) population density (TPD), canopy height, pre- and post-graze forage mass, pre-graze leaf:stem ratio (L:S), leaf area index (LAI), leaf elongation rate (LER), stem elongation rate (SLR), final leaf length (FLL), stem length (stem+pseudo-stem) (SL), number of live leaves per tiller (NLL), phyllochron (Phy), leaf life span (LLS), and leaf growth rate (LGR). The 100% LI treatment resulted in higher pre-graze forage mass (5200 kg DM ha-1) as well as and post-graze forage mass (1330 kg DM ha-1), as well as higher mean herbage accumulation (3870 kg DM ha-1). The 28-d treatment resulted in varying levels of pre-graze LI, although, on average, it was similar to the 95% LI treatment. The 95% LI and the 28-d resulted in lower pre-graze LAI (3.62 and 3.75, respectively), but the highest post-graze LAI. The L:S ratio did not vary across treatments, and neither did the TPD (total and aerial). The 100% LI treatment resulted in lowest basal DPP (1189 tillers m-2) and the 95% LI in the highest DPP (1260 tillers m-2). There was no difference among treatments for LAR, Phy, LLS, and NLL in any of the periods within the growing season. The 100% LI treatment resulted in higher FLL and LGR and the 95% LI in the lowest values for these responses. It is concluded that the use of LI as an indicator of the time for termination of regrowth and the beginning of grazing results in variations in the length of rest period in pastures under intermittent stocking. In addition, it is clear that the stem is the main component responsible for high rates of accumulation of tropical forage grass in situations of prolonged periods of rest. Studies to establish standards of \"physiological age\" may explain the contrast between the grazing treatments whose intervals are based on levels of light interception by the canopy during pasture regrowth.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-14T14:53:53Z No. of bitstreams: 1 Emanoel Cabral de Medeiros.pdf: 910531 bytes, checksum: a49d49dbcc2fa0475cf92eaff69ab023 (MD5) / Made available in DSpace on 2017-02-14T14:53:53Z (GMT). No. of bitstreams: 1 Emanoel Cabral de Medeiros.pdf: 910531 bytes, checksum: a49d49dbcc2fa0475cf92eaff69ab023 (MD5) Previous issue date: 2011-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Opuntia stricta Haw, cactus of great economic importance as forage in northeastern Brazil, was subjected to different in vitro systems and their performance was assessed by physiological and biochemical variables. We established three different cropping systems: temporary immersion system (TIS), with low frequency of immersion (immersion of one minute every 48 hours) and high-frequency TIS (immersion for five minutes every three hours); static culture in semi-solid medium (6.0 g.L-1 agar); static culture in liquid medium. The middle for inducing proliferation in vitro consisted of Murashige and Skoog (1962) salts and vitamins plus 30.0 g.L-1 sucrose and 0.0, 0.25, 0.5 or 1.0 mg.L-1 6-benzilaminpurine (BAP). Cultures were maintained in a growth room with 25 ± 2 º C under cool white light (40 mol.m-2.s-1), with 16 hours photoperiod. The experimental design was completely randomized factorial arrangement with 4 x 4 (cropping systems x BAP concentrations in the middle). After cultivation in vitro shoots of each treatment were acclimatized. Biochemical and biometrics analysis were performed on the material in vitro and biometrics on the acclimatized material. The static culture on solid medium, provided more stability since the multiplication by the acclimatization of the seedlings, while the systems with liquid presented limitations in some stages of micropropagation. The vitrification and the presence of betacyanin can be used as quality indicators physiological of the Elephant Ear Mexicana and its potential for acclimatization. / A Opuntia stricta Haw, cactácea de grande importância econômica como forrageira na região Nordeste do Brasil, foi submetida a distintos sistemas de cultivo in vitro e seu desempenho foi avaliado mediante variáveis fisiológicas e bioquímicas. Foram estabelecidos quatro diferentes sistemas de cultivo: sistema de imersão temporária (SIT), com baixa freqüência de imersões (imersão de um minuto a cada 48 horas); alta freqüência (imersão de cinco minutos a cada três horas); cultivo estático em meio semi-sólido (6,0 g.L-1 de ágar); cultivo estático em meio líquido. Os meios para indução de multiplicação in vitro constaram dos sais e vitaminas de Murashige e Skoog (1962) acrescidos de 30,0 g.L-1 de sacarose e 0,0; 0,25; 0,5 ou 1,0 mg.L-1 de 6 benzilaminopurina (BAP). As culturas foram mantidas em sala de crescimento com 25±2ºC, sob luz branca fria (40 μmol.m-2.s-1), com 16 horas de fotoperíodo. O desenho experimental foi o inteiramente casualizado com arranjo fatorial 4 x 4 (sistemas de cultivo x concentrações de BAP no meio). Após o cultivo in vitro, brotações de cada tratamento foram aclimatizadas. Análises bioquímicas e biométricas foram realizadas no material in vitro e biométricas no material aclimatizado. O cultivo estático em meio sólido, proporcionou mais estabilidade desde a multiplicação até a aclimatização das mudas, enquanto os sistemas com meio líquido apresentaram limitações em alguma das fases da micropropagação. A hiperidricidade e a presença de betacianina podem ser usadas como indicadores da qualidade fisiológica das mudas micropropagadas da Orelha de Elefante Mexicana e do seu potencial para aclimatização.

Submitted by (edna.saturno@ufrpe.br) on 2017-03-17T15:56:06Z No. of bitstreams: 1 Amanda Ferreira de Lima.pdf: 377887 bytes, checksum: fd40358a75475fdcdaedd3f5aa3cd8bc (MD5) / Made available in DSpace on 2017-03-17T15:56:06Z (GMT). No. of bitstreams: 1 Amanda Ferreira de Lima.pdf: 377887 bytes, checksum: fd40358a75475fdcdaedd3f5aa3cd8bc (MD5) Previous issue date: 2009-07-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The morphogenic characteristics of Panicum maximum Jacq. clones were evaluated during the regrowth period under water stress. The experiment was carried out in a greenhouse at the Animal Science Department - UFRPE, from March to September 2008. Samples collected in the of Sergipe state, municipalities of Pernambuco (São José da Coroa Grande, São Bento do Una and Itambé) and the Mombaça, Tanzania and Massai cultivars were evaluated. The seedlings were transplanted to experimental pots and fertilized with limestone and nitrogen. Two standardization cuts were performed and 27 days after the 2nd cut the clones were submitted to water stress. The establishment period until the application of water stress lasted 27 days. The experimental treatments were of 7, 14, 21 and 28 days without irrigation in order to evaluate the morphogenic characteristics in the regrowth period at 2, 4, 6, 8, 10, 12 and 14 days. A completely randomized design as a 4 x 7 (four periods of water stress x seven clones) factorial arrangement was used. Seven evaluations were performed in alternated days during the regrowth period. Estimates of plant height, leaf blade length, number of emerging green leaves, number of dead leaves and total number of tiller were the morphogenic characteristics evaluated during the regrowth period. Clone means were submitted to Tukey test at 5% of probability. Number of tillers, leaf blade length, plant height, number of dead leaves and number of green leaves were submitted to the analysis of variance in a repeated measure model within each stress period. No significant effect on clone regrowth under water stress from 7 to 28 days was detected. The highest water stress level favor the plant development after cutting. / Objetivou-se avaliar as características morfogênicas de clones de Panicum maximum Jacq. durante o período de rebrote após períodos de suspensão hídrica. O experimento foi realizado no Telado do Departamento de Zootecnia da UFRPE, no período de março a setembro de 2008. Foram avaliados materiais coletados nos municípios de Sergipe, São José da Coroa Grande, São Bento do Una e Itambé e os cultivares Mombaça, Tanzânia e Massai. As mudas foram transplantadas para vasos com capacidade para 7,5kg, preenchidos com solo previamente destorroado e corrigido, na proporção de 2 t/ha, fevereiro de 2008. Realizou-se adubação nitrogenada, na proporção de 50 kg/ha, em abril de 2008. Após o período de estabelecimento foram aplicados os períodos de suspensão hídrica. Foram realizados dois cortes de uniformização e 27 dias após o 2o corte os clones foram submetidos à suspensão hídrica. O período de estabelecimento até a aplicação dos períodos de estresse durou 37 dias. Os tratamentos experimentais constaram de submeter os clones a períodos de suspensão hídrica (sete, quatorze, vinte e um e vinte e oito dias sem irrigação) e avaliar as características morfogênicas no período de rebrota. O delineamento experimental utilizado foi o inteiramente casualizado, em um arranjo fatorial quatro x sete. Foram realizadas sete avaliações em dias alternados no período de rebrote. As variáveis estudadas foram altura da planta, comprimento da lâmina foliar, número de folhas verdes em expansão, número de folhas mortas e número total de perfilhos. Para comparação entre médias de clones utilizou-se o teste Tukey, a 5% de probabilidade. A rebrota dos clones avaliados pouco diferenciam após níveis de suspensão hídrica de 7 a 28 dias. O maior nível de suspensão hídrica avaliado favorece o desenvolvimento da planta após o corte.

Les épithéliums jouent le rôle de barrière physique et chimique chez les Métazoires. Les épithéliums subissent des remodelages pendant l’embryogénèse. La morphogénèse des tissus est dirigée par des déformations cellulaires coordonnées fonctionnant grâce à des réseaux contractiles intracellulaires constitués d’actine et de myosine. Ce réseau d’actomyosine peut être soit pulsatile, soit stable. Un exemple est l’élongation de l’ectoderme ventro-latéral par intercalation cellulaire, le long de l’axe antéro-postérieur (AP) de l’embryon de la Drosophile. Les jonctions parallèles à l’axe dorso-ventral (DV) rétrécissent et forment de manière irréversible de nouvelles jonctions parallèles à l’axe AP. Des pulsations de myosine-II (Myo-II) médio-apicale se déplacent de manière anisotrope vers les jonctions parallèles à l’axe DV. Ceci provoque le rétrécissement graduel des jonctions, rétrécissement stabilisé par une population de Myo-II polarisée dans le plan du tissu et enrichie au niveau de ces jonctions. Les mécanismes cellulaires qui régulent la pulsatilité, la stabilité et la polarité de la Myo-II restent à élucider. Lors de ma thèse, j’ai identifié de nouveaux effecteurs régulant l’activation et la polarité planaire de la voie Rho1-Rok-Myo-II aux niveaux des jonctions. J'ai d'abord caractérisé le rôle de la kinase Misshapen dans l’activation polarisée de la voie Rho1 au niveau des jonctions. Misshapen agit en aval de la signalisation GPCR afin de favoriser l’activation de Rho1 et contrôle la polarisation de cette activation en transmettant l’information des récepteurs Toll. Puis j'ai identifié Pebble comme la RhoGEF régulant Rho1 et l'accumulation de Myo-II aux jonctions. / Epithelial build up strong mechanical and chemical barriers in Metazoans. Epithelia can be dramatically remodeled during embryogenesis. Tissue morphogenesis is driven by coordinated cellular deformations which are powered by intracellular contractile networks constituting actin and Myosin. Actomyosin networks can either be pulsatile or stable. One example is the elongation of the ventral-lateral ectoderm by cell intercalation, along antero-posterior (AP) axis of Drosophila embryo. Junctions parallel to the dorso-ventral (DV) axis shrink and form new junctions along AP axis. Medial apical Myosin-II (Myo-II) pulses flow anisotropically towards junctions aligned in DV axis, resulting in steps of junction shrinkage which are stabilized by a planar-polarized pool of Myo-II enriched at these junctions. Sequential deformation and stabilization drive irreversible tissue deformations akin to a ratchet. The cellular mechanisms that regulate Myo-II pulsatility, stability and polarity remained to be unfurled. During my PhD, I identified new regulators for Rho1-Rok-Myo-II pathway at junctions, and Myo-II planar polarity. On the one hand, I characterized the function of Misshapen kinase in polarized activation of Rho1 pathway at junctions. Misshapen acts downstream GPCR signaling to enhance Rho1 activation, and controls the polarization of this activation by transducing information from Toll receptors. Also, I identified Pebble as RhoGEF regulating Rho1 at junctions and Myo-II accumulation.

Introdução: As glândulas salivares humanas passam por diversos e complexos processos durante o período de desenvolvimento, até que adquiram maturidade estrutural para desempenhar sua função, a formação e secreção de saliva. Considerada essencial à saúde e homeostase da cavidade oral, a saliva é um fluido aquoso que depende de um mecanismo de transporte entre as membranas celulares por meio das aquaporinas. A família de proteínas aquaporinas possui treze membros. Somente algumas dessas proteínas atuam nas glândulas salivares formando poros na bicamada lipídica das membranas celulares facilitando o transporte de água e pequenos solutos, cruciais à regulação da qualidade e quantidade de saliva secretada. Proposição: Diante deste cenário, avaliamos por meio da técnica de imunoistoquímica o padrão de expressão das aquaporinas 1, 3 e 5 de glândulas salivares em desenvolvimento, com o intuito de contribuir com informações de base para futuras pesquisas. Metodologia: 47 espécimes parafinados de glândulas salivares em desenvolvimento, de diferentes sítios da cavidade oral de 20 fetos humanos, com idade entre 14 e 25 semanas, foram submetidos à técnica de imunoperoxidase. Os resultados foram analisados, de acordo com o estágio da morfogênese glandular e localização da expressão das aquaporinas. Resultados: Na fase de botão, houve a expressão das aquaporinas 1, 3 e 5 em todas as células epiteliais; na fase pseudoglandular, a expressão dessas proteínas foi vista nos ductos rudimentares (com exceção da aquaporina 1) e nas porções terminais (futuros ácinos); na fase canalicular as aquaporinas foram principalmente detectadas nos ácinos rudimentares e ductos. Finalmente, na fase de botão terminal, as aquaporinas 3 e 5 foram detectadas nas membranas das células acinares e os ductos expressaram todas as aquaporinas. Conclusão: O presente trabalho evidenciou a imunoexpressão das aquaporinas 1, 3 e 5 nas glândulas salivares humanas durante o período de embriogênese. A análise topográfica dessas proteínas nos permitiu identificar diferenças no padrão de expressão entre as diferentes regiões estruturais e estágios do desenvolvimento glandular, sugerindo diferentes papéis para cada proteína / Introduction: The human salivary glands morphogenesis depends on complex processes during the development period until they reach full structural maturity to perform its function - the synthesis and secretion of saliva. The saliva is a complex aqueous fluid considered essential to health and homeostasis of the oral cavity; its synthesis depends on several molecular mechanisms, including the transport of water, solutes, ions, amongst others across the cell membranes. The aquaporin family of proteins is essential in this process. This protein family consists of thirteen members that form channels across the cell membrane facilitating water and small solutes transportation, crucial to the regulation of quality and quantity of secreted saliva. Aims: In this scenario, we evaluated, using the immunohistochemistry technique, the expression pattern of aquaporins 1, 3 and 5 in the different phases of salivary glands development, in order to understand the role of these protein in the formation of human salivary gland morphogenesis. Methodology: 47 specimens of paraffin embedded human salivary glands at various developmental phases were included in the study. The specimens were derived from various sites of the oral cavity of 20 human fetuses aged between 14 and 25 weeks of gestation. All specimens were subjected to the imunohistochemical immunoperoxidase technique. The results were qualitatively and semiquantitatively analyzed according to the stage of glandular morphogenesis and express location of aquaporin. Results: In the bud stage, there was expression of aquaporin 1, 3 and 5 in all glandular epithelial cells; in pseudoglandular stage, the expression of these proteins was seen in rudimentary ducts (except aquaporin-1) and the terminal end buds (future acini); in the canalicular phase the aquaporins were mainly detected in the rudimentary ducts and acini. Finally, in terminal bud stage, the aquaporin 3 and 5 were detected in the membranes of the ducts and acinar cells expressed all aquaporins. Conclusion: This study showed the presence of aquaporins 1, 3 and 5 in human salivary glands during embryogenesis period. The topographic analysis of these proteins allowed us to identify differences in the expression pattern between the different structural regions and stages of glandular development, suggesting different roles for each of these proteins

La formation d'un organe repose sur la coordination spatio-temporelle du positionnement et de la différenciation de progéniteurs. La finalité de ces évènements permet la constitution structurelle de l'organe et la production de la diversité cellulaire nécessaire pour assurer ses fonctions. L'épithélium olfactif de l'embryon de poisson-zèbre est issu de la migration de progéniteurs qui vont générer entre autres les neurones olfactifs. Au cours de ma thèse je me suis intéressé aux bases génétiques et moléculaires de la coordination de la morphogenèse et de la neurogenèse de cet épithélium tout en étudiant l'origine de la diversité des types cellulaires olfactifs. L'imagerie en temps réel m'a permis de caractériser la migration de ces progéniteurs en générant une carte morphométrique de leur déplacement. Mon travail de thèse révèle que le proneural Neurog1 régule directement l'expression de cxcr4b, un récepteur au chimiokine, dans les progéniteurs olfactifs assurant leur positionnement. Ainsi, Neurog1 coordonnerait la position et l'identité des progéniteurs olfactifs via ses cibles transcriptionnelles. Au sein de l'épithélium olfactif dans l'embryon, deux populations cellulaires (neurones à GnRH et neurones à microvillosités) ont été décrites comme provenant des crêtes neurales céphaliques (CNC). J'ai pu montrer que l'expression de marqueurs spécifiques de ces populations n'est pas affectée dans un contexte d'absence de différenciation des CNCs (sox10-/-) suggérant que ces types cellulaires ne dérivent pas de ce territoire. Afin d'identifier leur territoire d'origine, j'ai développé une méthode d'imagerie en temps réel, le backtracking, qui m'a permis de déterminer que la région de la placode olfactive, et non les crêtes neurales, génère ces deux types cellulaires. Ainsi j'ai pu définir la source de ces deux populations neuronales tout en minimisant la contribution des crêtes neurales. En conclusion mes résultats suggèrent que la diversité des neurones olfactifs serait produite localement et ceci conjointement à la morphogenèse de l'épithélium. / The correct development of sensory organs relies on the coordination between changes in progenitor positioning over time and the differentiation/specification of different neural subtypes. The outcome of this coordination is proper organ shape and cell diversity, which are required for functionality. The zebrafish embryonic olfactory epithelium arises from progenitor migration and differentiation. During my PhD, I studied the genetic and molecular basis of morphogenesis in this tissue, and how this is coordinated with neurogenesis, as well as revisiting the origin of olfactory cell type diversity.First, I generated a morphometric map of olfactory progenitors through the characterization of their migration in live embryos. Next, I showed that the proneural transcription factor Neurog1 directly regulates cxcr4b expression, a chemokine receptor that has already been shown to govern olfactory progenitor positioning. Thus, Neurog1 orchestrates olfactory progenitor position and the generation of olfactory neurons via distinct transcriptional targets. Secondly, I addressed the origin of olfactory neuron diversity. Within the embryonic olfactory epithelium, two cell populations (GnRH neurons and microvillous neurons) have been described as cephalic neural crest (CNC) derivatives. I found, however, that the expression of specific markers of both populations is unaffected in a genetic context blocking CNC differentiation. To revisit the lineage assignment of these cell types, I developed a backtracking approach through time-lapse live imaging. I found that both populations are derived from classical olfactory placode progenitor and not the CNC. In conclusion, my results indicate that heterogeneity of olfactory cell-types is locally generated, and concomitant with morphogenesis of the placode.