• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • Tagged with
  • 19
  • 19
  • 19
  • 19
  • 14
  • 13
  • 10
  • 9
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Express?o de genes relacionados ? absor??o e metabolismo de nitrog?nio em arroz sob alto e baixo suprimento de nitrato

Bucher, Carlos Alberto 23 February 2011 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-09T12:24:30Z No. of bitstreams: 1 2011 - Carlos Alberto Bucher.pdf: 775464 bytes, checksum: 84e941a946068132678bc3f55c09561d (MD5) / Made available in DSpace on 2016-08-09T12:24:30Z (GMT). No. of bitstreams: 1 2011 - Carlos Alberto Bucher.pdf: 775464 bytes, checksum: 84e941a946068132678bc3f55c09561d (MD5) Previous issue date: 2011-02-23 / Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do RJ - FAPERJ / Nitrogen is one of the nutrient elements most limiting for plant growth. Thus, increasing plant nitrogen usage efficiency (NUE) is an essential factor for sustainable agriculture, leading to an increased food production with less fertilizer input and less environment impact. NUE in plant involves the uptake and accumulation efficiency, and N use efficiency for grain production. Understanding the mechanisms regulating these processes is crucial for the improvement of NUE in crops. Therefore, is essential to comprehend plants response to different N regimes, mainly N limitation. The usage of plants or varieties with differences in nutrient use efficiency is another important factor to determine the main mechanisms involved in these processes. The objectives of this study were to evaluate N metabolism and expression of genes involved in N uptake and assimilitation of two rice varieties (Piau? and IAC-47), under different N supply conditions. The N metabolism was evaluated by quantification of nitrogen fractions in plant tissue and enzymatic activity, expression of genes that code for high and low affinity N transporters, and N assimilation enzymes. Two experiments were conducted: the first, to investigate the plants behavior when grown under high and low N supply; and the second to verify plants response to NO3 - resupply. The IAC-47 variety showed greatest mass accumulation in all treatments. When plants were grown for a long period under low N supply it was observed a higher nitrate (NO3 -) content in the tissue of Piau? variety, which is adapted to low fertility conditions, as well as a high activity of nitrate reductase and glutamine synthetase in the roots of these plants. When under high NO3 - supply for a long period, Piau? variety had higher NO3 - concentrations in roots and sheaths, but no differences were observed in enzymes activity. The nitrate transporters expression was higher in roots of Piau? plants under low supply of NO3 - when compared to Piau? plants under high N supply. Nitrate transporters expression in roots of IAC-47 plants showed a pattern opposite to the one observed for Piau? plants. When plants were resupplied with NO3 -, after a 72 hours period without N, there was a rapid increase, after 6 hours of resupply, in the expression of high affinity nitrate transporters genes (OsNRT2.1) and the plastidial glutamine synthetase (GS2) in the Piau? variety roots, and a higher expression of these in IAC-47 roots after a 24 hours of N resupply. The efficiency of Piau? variety is related to the differentiated control of N absorption and assimilation mechanisms, which allow bigger expression of high affinity nitrate transporters in tissue with high levels of soluble N, high N status, indicating that the control of nitrogen uptake system may be essential for the nitrogen usage efficient. / O nitrog?nio ? um dos elementos minerais que mais limita o desenvolvimento das plantas. Assim, aumentar a efici?ncia de uso de nitrog?nio (EUN) ? um fator ? essencial para uma agricultura sustent?vel, levando a um aumento da produ??o de alimentos com menor uso de insumos e menos impactos ao ambiente. A EUN envolve a efici?ncia de absor??o e ac?mulo e a efici?ncia de utiliza??o de N para produ??o. Compreender os mecanismos envolvidos nesses processos e como eles s?o controlados ? fundamental para a melhoria da EUN nas plantas cultivadas. Para isso, ? essencial entender a resposta e comportamento das plantas a diferentes regimes de N, principalmente ? limita??o de N. O uso de plantas ou variedades com diferen?as na EUN ? outro fator importante para verificar os principais mecanismos envolvidos. Este trabalho teve por objetivo desse trabalho foi verificar o metabolismo e a express?o de genes envolvidos na absor??o e assimila??o de nitrog?nio nas variedades de arroz Piau? e IAC-47 sob diferentes condi??es de disponibilidade desse nutriente. O metabolismo de N foi avaliado atrav?s da quantifica??o das fra??es nitrogenadas no tecido e atividade enzim?tica, a express?o de genes que codificam para transportadores de N de alta e baixa afinidade e enzimas de assimila??o de N. Foram realizados dois experimentos: o primeiro para verificar o comportamento das plantas quando cultivadas sob alto e baixo suprimento de N; e o segundo, para verificar as repostas ao ressuprimento de N. O ac?mulo de massa foi maior na variedade IAC-47 em todos os tratamentos. Quando as plantas foram cultivadas por um longo per?odo sob baixo suprimento de N foi observado maior teor de nitrato (NO3 -) no tecido da variedade Piau?, adaptada a condi??es de baixa fertilidade, assim como uma alta atividade da nitrato redutase e glutamina sintetase nas ra?zes dessas plantas. Sob alto suprimento de NO3 -, por um longo per?odo, a variedade Piau? apresentou maiores teores de NO3 - nas bainhas e ra?zes, mas n?o foram observas diferen?as na atividade de enzimas. A express?o dos transportadores de nitrato na variedade Piau? foi mais elevada nas ra?zes das plantas sob baixo suprimento de NO3 - quando comparado as plantas sob alto suprimento de N. Na variedade IAC-47 a express?o dos transportadores de NO3 - teve comportamento oposto ao observado para a Piau?. Quando as plantas receberam NO3 -, ap?s um per?odo de 72 horas sem N, houve um r?pido aumento, ap?s 6 horas do ressuprimento, na express?o do gene que codifica para o transportador de NO3 - de alta afinidade OsNRT2.1 e glutamina sintetase plastidial (GS2) nas ra?zes da variedade Piau?, e 24 horas ap?s o ressuprimento a express?o foi maior na variedade IAC-47. A efici?ncia da variedade Piau? esta relacionada ao controle diferenciado dos mecanismos de absor??o e assimila??o de N, que permite a maior express?o dos transportadores de nitrato de alta afinidade em tecido com altos teores de N sol?vel, alto status de N, indicando que o controle do sistema de absor??o de N pode ser essencial para a efici?ncia no uso de nitrog?nio.
12

Express?o g?nica relacionada ? produ??o de ?leo essencial e avalia??o do metabolismo de Mentha arvensis L. sob diferentes condi??es de cultivo / Gene expression related to production of essential oil and evaluation of Mentha arvensis metabolism under different conditions of cultivation

Souza, Marco Andre Alves de 18 January 2010 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-03-30T12:28:08Z No. of bitstreams: 1 2010 - Marco Andre Alves de Souza.pdf: 5657340 bytes, checksum: becf46e090a1ebcc4a731b733c77fb6a (MD5) / Made available in DSpace on 2017-03-30T12:28:08Z (GMT). No. of bitstreams: 1 2010 - Marco Andre Alves de Souza.pdf: 5657340 bytes, checksum: becf46e090a1ebcc4a731b733c77fb6a (MD5) Previous issue date: 2010-01-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / The cultivation of aromatic specimens for obtaining essential oils have great economic importance, mainly by increasing demand in the food, cosmetic and pharmaceutical industry. Brazil is the largest producer of essential oil, however, is what earns less in money value, because, its production is mainly of orange essential oil, with low added value. The essential oil of M. arvensis is rich in menthol (70-80%), a natural products with higher demand in daily life of modern man. Currently, Brazil has become a major importer of menthol which has contributed negatively to the brazilian trade balance. Thus, for the development of this work was chosen to be a specimens of economic interest and social demand, the Mentha arvensis. The purpose of study was to evaluate whether changes in light intensities and different levels of phosphorus promote changes in biomass production and nutrition, with consequences for the biosynthesis of essential oils. We also analyzed the influence of leaf age on the quality of essential oil. To this end, the plant of M. arvensis was grown under the effect of different conditions, which allowed the analysis of the levels of soluble fractions, of photosynthetic pigments, the activities of enzymes related to nitrogen assimilation and the anatomical and histochemical study of trichomes, morphological structure where it is produce the essential oil. The study also included analysis of the expression of genes related to the route of menthol synthesis. The essential oil was obtained by extraction with hydrodestillation in modified Clevenger and the chemical analysis of substances obtained by GC-MS. The Kovats index was used to collaborate in identification of the main substances in essential oil. The results showed that the essential oil quality is determined by physiological conditions and leaf age and that the production is dependent on the synthesis efficiency and density of trichomes on the leaves. In addition, it was found that different concentrations of phosphorus affected some aspects of plant metabolism, which reflected the production of biomass in the soluble fraction, with consequences on production and quality of essential oils. Also showed that variations in light levels affected the expression of six of the eight genes involved in the route of synthesis of menthol, in plants of M. arvensis and that changes in gene expression are probably associated with a transcription factor, which could be acting on the whole pathway. All of this information showed that environmental conditions and / or nutritional affected some aspects of plant metabolism, which reflected the production of biomass, of trichomes and on the expression of genes related to the route of menthol, which reflect on the quality and the production of essential oils / O cultivo de esp?cies arom?ticas para a obten??o de ?leos essenciais tem grande import?ncia econ?mica, principalmente, pela crescente demanda nas ind?strias de alimentos, de cosm?ticos e a farmac?utica. O Brasil ? o maior produtor de ?leo essencial, entretanto, ? o que menos arrecada em valores monet?rios, pois, sua produ??o ? basicamente de ?leo essencial de laranja, com baixo valor agregado. O ?leo essencial de Mentha arvensis L. ? rico em mentol (70-80%), uma dos produtos naturais com maior demanda no dia-a-dia do homem moderno. Atualmente, o Brasil tornou-se um grande importador de mentol o que tem contribu?do negativamente para a balan?a comercial brasileira. Deste modo, para o desenvolvimento deste trabalho escolheu-se a planta M. arvensis. O objetivo do estudo foi avaliar se varia??es nas intensidades luminosas e diferentes concentra??es de f?sforo promovem altera??es na produ??o de biomassa e em aspectos nutricionais, com reflexos na bioss?ntese de ?leos essenciais. Tamb?m foi avaliada a influ?ncia da idade da folha sobre a qualidade do ?leo essencial. Com esta finalidade, a planta de M. arvensis foi cultivada sob o efeito de diferentes condi??es, o que permitiu a an?lise dos teores das fra??es sol?veis, dos pigmentos fotossint?ticos, das atividades das enzimas relacionadas com a assimila??o do nitrog?nio e o estudo histoqu?mico e anat?mico dos tricomas secretores, estrutura morfol?gica onde ? produzido o ?leo essencial. Tamb?m foram realizadas analises da express?o dos genes relacionados com a rota de s?ntese do mentol. O ?leo essencial foi obtido por hidrodestila??o em Clevenger modificado e as analises qu?micas das subst?ncias realizadas por CG/EM. A utiliza??o do ?ndice de Kovats auxiliou na identific??o das principais subst?ncias no ?leo essencial. Os resultados permitiram concluir que a qualidade do ?leo essencial ? determinada pelas condi??es fisiol?gicas e a idade das folhas e que a produ??o ? dependente da efici?ncia de s?ntese e a densidade de tricomas secretores nas folhas. Al?m disso, foi constatado que as diferentes concentra??es de f?sforo afetaram alguns aspectos do metabolismo vegetal, os quais refletiram na produ??o de biomassa, nas fra??es sol?veis, com conseq??ncias na produ??o e qualidade dos ?leos essenciais. Tamb?m, mostraram que varia??es nos n?veis de luminosidade afetaram a express?o de seis entre os oito genes envolvidos com a rota de s?ntese do mentol, em plantas de M. arvensis e que as altera??es na express?o dos genes provavelmente est?o associados a um fator de transcri??o, o qual deve estar atuando sobre toda a rota metab?lica
13

Algoritmos de agrupamento aplicados a dados de express?o g?nica de c?ncer: um estudo comparativo

Ara?jo, Daniel Sabino Amorim de 11 November 2008 (has links)
Made available in DSpace on 2014-12-17T15:47:48Z (GMT). No. of bitstreams: 1 DanielSAA.pdf: 691771 bytes, checksum: c2a3333a69e8d426409687ac8cfac27f (MD5) Previous issue date: 2008-11-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The use of clustering methods for the discovery of cancer subtypes has drawn a great deal of attention in the scientific community. While bioinformaticians have proposed new clustering methods that take advantage of characteristics of the gene expression data, the medical community has a preference for using classic clustering methods. There have been no studies thus far performing a large-scale evaluation of different clustering methods in this context. This work presents the first large-scale analysis of seven different clustering methods and four proximity measures for the analysis of 35 cancer gene expression data sets. Results reveal that the finite mixture of Gaussians, followed closely by k-means, exhibited the best performance in terms of recovering the true structure of the data sets. These methods also exhibited, on average, the smallest difference between the actual number of classes in the data sets and the best number of clusters as indicated by our validation criteria. Furthermore, hierarchical methods, which have been widely used by the medical community, exhibited a poorer recovery performance than that of the other methods evaluated. Moreover, as a stable basis for the assessment and comparison of different clustering methods for cancer gene expression data, this study provides a common group of data sets (benchmark data sets) to be shared among researchers and used for comparisons with new methods / O uso de t?cnicas de agrupamento na descoberta de subtipos de c?ncer tem atra?do grande aten??o da comunidade cient?fica. Enquanto bioinformatas prop?em novas t?cnicas de agrupamento que levam em considera??o caracter?sticas dos dados de express?o g?nica, a comunidade m?dica prefere utilizar as t?cnicas cl?ssicas de agrupamento. De fato, n?o existem trabalhos na literatura que realizam uma avalia??o em grande escala de t?cnicas de agrupamento nesse contexto. Diante disso, este trabalho apresenta o primeiro estudo em grande escala de sete t?cnicas de agrupamento e quatro medidas de proximidade para a an?lise de 35 conjuntos de dados de express?o g?nica. Mais especificamente, os resultados mostram que a t?cnica mistura finita de gaussianas, seguida pelo k-means, apresentam os melhores resultados em termos de recupera??o da estrutura natural dos dados. Esses m?todos tamb?m apresentam a menor diferen?a entre o n?mero real de classes e o n?mero de grupos presente na melhor parti??o. Al?m disso, os m?todos de agrupamento hier?rquico, que v?m sendo bastante utilizados pela comunidade m?dica, apresentaram os piores resultados quando comparados com os outros m?todos investigados. Este trabalho tamb?m apresenta, como uma refer?ncia est?vel para a avalia??o e compara??o de diferentes algoritmos de agrupamento para dados de express?o g?nica de c?ncer, um conjunto de bases de dados (benchmark data sets) que pode ser compartilhado entre pesquisadores e usado na compara??o de novos m?todos
14

An?lise filogen?tica e funcional de dois genes de reparo hom?logos a AP endonuclease em cana-de-a??car: ScARP1 e ScARP3

Medeiros, Nathalia Maira Cabral de 21 March 2014 (has links)
Made available in DSpace on 2014-12-17T14:03:44Z (GMT). No. of bitstreams: 1 NathaliaMCM_DISSERT.pdf: 2544480 bytes, checksum: eab320fea2fc6e6b04c8d45099041a93 (MD5) Previous issue date: 2014-03-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The genome of all organisms constantly suffers the influence of mutagenic factors from endogenous and/or exogenous origin, which may result in damage for the genome. In order to keep the genome integrity there are different DNA repair pathway to detect and correct these lesions. In relation to the plants as being sessile organisms, they are exposed to this damage frequently. The Base Excision DNA Repair (BER) is responsible to detect and repair oxidative lesions. Previous work in sugarcane identified two sequences that were homologous to Arabidopsis thaliana: ScARP1 ScARP3. These two sequences were homologous to AP endonuclease from BER pathway. Then, the aim of this work was to characterize these two sequence using different approaches: phylogenetic analysis, in silico protein organelle localization and by Nicotiana tabacum transgenic plants with overexpression cassette. The in silico data obtained showed a duplication of this sequence in sugarcane and Poaceae probably by a WGD event. Furthermore, in silico analysis showed a new localization in nuclei for ScARP1 protein. The data obtained with transgenic plants showed a change in development and morphology. Transgenic plants had slow development when compared to plants not transformed. Then, these results allowed us to understand better the potential role of this sequence in sugarcane and in plants in general. More work is important to be done in order to confirm the protein localization and protein characterization for ScARP1 and ScARP3 / O genoma de todos os organismos sofre constantemente a influ?ncia de fatores mutag?nicos que podem ser de origem end?gena e/ou ex?gena, estes podem resultar em danos ao material gen?tico. Se esses danos n?o forem corrigidos pode levar ao aparecimento de muta??es. As plantas por serem organismos sesseis est?o continuamente expostas a estes fatores. Considerando isto, os organismos (animais e vegetais) possuem diferentes vias de reparo de DNA para manter a integridade do material gen?tico. Dentro destas vias, h? a via de Reparo por Excis?o de Bases (BER) que ? composta por diferentes enzimas, e dentro dessa via h? a enzima AP endonuclease que ? alvo deste estudo. Trabalhos anteriores em cana-de-a??car identificaram duas sequ?ncias de cDNA hom?logas a esta prote?na que foram denominadas ScARP1 e ScARP3. Com isso, o objetivo deste trabalho foi caracterizar estas duas sequ?ncias por meio de an?lises filogen?ticas utilizando sequ?ncias presentes dentro do reino Plantae, e de an?lises estruturais dos genes de AP endonuclease por an?lise in silico e por plantas transg?nicas contendo cassetes de super-express?o. Al?m disso, foi realizado transforma??es e a obten??o plantas transg?nicas de Nicotiana tabacum contendo cassetes de super-express?o em orienta??o anti-senso. Foi tamb?m analisado a rela??o filogen?tica de genes DNA ligase I presentes no organismo vegetal de estudo. Os resultados obtidos permitiram verificar que as sequ?ncias ScARP1 e ScARP3 correspondem a uma duplica??o, provavelmente devido a um processo de duplica??o do genoma como um todo (WGD) que deve ter ocorrido no grupo das gram?neas (Poaceae). Refor?ando estes dados, foi verificado um poss?vel direcionamento da prote?na para organelas diferentes, sendo que a ScARP1 pode ser encontrada no n?cleo e a ScARP3 em mitocondrias e/ou cloroplasto. Com rela??o as plantas transg?nicas contendo o cassete em orienta??o anti-senso foi observado que estas apresentaram crescimento lento quando comparado com a planta selvagem (n?o transformada). Al?m disso, seu fen?tipo abrange altera??es morfol?gicas no crescimento foliar, baixa estatura e diminui??o na produ??o de sementes. Entretanto, ainda se faz necess?rio a obten??o da linhagem homozigota para aprofundar essas observa??es. Desta forma, estes resultados permitem compreender um pouco melhor do poss?vel papel da enzima AP endonuclease em cana-de-a??car e em plantas
15

Avalia??o do status antioxidante, express?o g?nica e polimorfismos dos genes SOD1, SOD2 e GPx1 em crian?as, adolescentes e adultos jovens com diabetes tipo 1

Oliveira, Yonara Monique da Costa 27 February 2012 (has links)
Made available in DSpace on 2014-12-17T14:16:36Z (GMT). No. of bitstreams: 1 YonaraMCO_DISSERT.pdf: 1678750 bytes, checksum: 32e7b234c6a83f6881e86eb536e38bec (MD5) Previous issue date: 2012-02-27 / Studies report that the pathophysiological mechanism of diabetes complications is associated with increased production of Reactive Oxygen Species (ROS)-induced by hyperglycemia and changes in the capacity the antioxidant defense system. In this sense, the aim of this study was to evaluate changes in the capacity of antioxidant defense system, by evaluating antioxidant status, gene expression and polymorphisms in the genes of GPx1, SOD1 and SOD2 in children, adolescents and young adults with type 1 diabetes. We studied 101 individuals with type 1 diabetes (T1D) and 106 normoglycemic individuals (NG) aged between 6 and 20 years. Individuals with type 1 diabetes were evaluated as a whole group and subdivided according to glycemic control in DM1G good glycemic control and DM1P poor glycemic control. Glycemic and metabolic control was evaluate by serum glucose, glycated hemoglobin, triglycerides, total cholesterol and fractions (HDL and LDL). Renal function was assessed by measurement of serum urea and creatinine and albumin-to-creatinine ratio (ACR) in spot urine. Antioxidant status was evaluate by content of reduced glutathione (GSH) in whole blood and the activity of erythrocyte enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD). We also analyzed gene expression and gene polymorphisms of GPx1 (rs1050450), SOD1 (rs17881135) and SOD2 (rs4880) by the technique of real-time PCR (Taqman?). Most individuals with DM1 (70.3%) had poor glycemic control (glycated hemoglobin> 8%). Regarding the lipid profile, individuals with type 1 diabetes had significantly elevated total cholesterol (p <0.001) and LDL (p <0.000) compared to NG; for triglycerides only DM1NC group showed significant increase compared to NG. There was an increase in serum urea and RAC of individuals with DM1 compared to NG. Nine individuals with type 1 diabetes showed microalbuminuria (ACR> 30 mg / mg). There was a decrease in GSH content (p = 0.006) and increased erythrocyte GPx activity (p <0.001) and SOD (p <0.001) in DM1 group compared to NG. There was no significant difference in the expression of GPx1 (p = 0.305), SOD1 (.365) and SOD2 (0.385) between NG and DM1. The allele and genotype frequencies of the polymorphisms studied showed no statistically significant difference between the groups DM1 and NG. However, the GPx1 polymorphism showed the influence of erythrocyte enzyme activity. There was a decrease in GPx activity in individuals with type 1 diabetes who had a polymorphic variant T (p = 0.012). DM1 patients with the polymorphic variant G (AG + GG) for polymorphism of SOD2 (rs4880) showed an increase in the RAC (p <0.05). The combined data suggest that glucose control seems to be the predominant factor for the emergence of changes in lipid profile, renal function and antioxidant system, but the presence of the polymorphisms studied may partly contribute to the onset of complications / Estudos relatam que o mecanismo fisiopatol?gico das complica??es do diabetes est? associado ao aumento na produ??o de Esp?cies Reativas de Oxig?nio (ERO) induzido pela hiperglicemia persistente e altera??es na capacidade de defesa do sistema antioxidante. Nesse sentido, o presente estudo teve como objetivo avaliar altera??es na capacidade de defesa do sistema antioxidante, atrav?s da avalia??o do status antioxidante, express?o g?nica e pesquisa de polimorfismos nos genes da GPx1, SOD1 e SOD2 de crian?as, adolescentes e adultos jovens com Diabetes Mellitus tipo 1 (DM1). Foram estudados 101 indiv?duos com diabetes tipo 1 (DM1) e 106 indiv?duos normoglic?micos (NG) com idade entre 6 e 20 anos. Os indiv?duos com DM1 foram avaliados como um grupo total e subdivididos de acordo com o controle glic?mico em DM1NC diab?tico n?o-compensado e DM1C diab?ticos compensados. Para avaliar o controle glic?mico e metab?lico foram realizadas as dosagens de glicose s?rica, hemoglobina glicada, triglicer?deos, colesterol total e fra??es (HDL e LDL). A fun??o renal foi avaliada pelas dosagens de ureia e creatinina s?ricas e a rela??o albumina/creatinina (RAC) urin?ria. Os par?metros antioxidantes avaliados foram o conte?do da glutationa reduzida (GSH) em sangue total e a atividade eritrocit?ria das enzimas glutationa peroxidase (GPx) e super?xido dismutase (SOD). Tamb?m foi avaliada a express?o g?nica e a pesquisa dos polimorfismos dos genes GPx1 (rs1050450), SOD1(rs17881135) e SOD2 (rs4880) pela t?cnica da PCR em tempo real (Taqman?). A maioria dos indiv?duos com DM1 (70,3%) apresentou controle glic?mico insatisfat?rio (hemoglobina glicada >8%). Em rela??o ao perfil lip?dico, indiv?duos com DM1 apresentaram valores significativamente elevados de colesterol total (p<0,001) e LDL (p<0,000) em rela??o ao NG; para os triglicer?deos s? o grupo DM1NC apresentou aumento significante em rela??o ao NG. Observou-se o aumento na ur?ia s?rica e na RAC dos indiv?duos com DM1 em rela??o ao NG. Nove dos indiv?duos com DM1 apresentaram microalbumin?ria (RAC> 30 &#956;g/mg). Houve diminui??o no conte?do de GSH (p=0,006) e aumento na atividade eritrocit?ria da GPx (p<0,001) e SOD (p<0,001) do grupo DM1 em rela??o ao NG. N?o foi observada diferen?a significante na express?o de GPx1 (p=0,305), SOD1 (0,365) e SOD2 (0,385) entre NG e DM1. As freq??ncias genot?picas e al?licas dos polimorfismos estudados n?o mostraram diferen?a estatisticamente significante entre os grupos DM1 e NG. Por?m o polimorfismo da GPx1 mostrou influ?ncia na atividade eritrocit?ria da enzima, observando-se diminui??o da atividade nos indiv?duos com DM1 que possu?am a variante polim?rfica T (p=0,012). J? para o polimorfismo Ala16Val da SOD2 observou-se eleva??o da RAC para aqueles indiv?duos diab?ticos que possu?am o alelo G (p<0,05). O conjunto dos dados sugere que o controle glic?mico parece ser o fator predominante para o surgimento de altera??es no perfil lip?dico, fun??o renal e no sistema antioxidante, por?m a presen?a dos polimorfismos estudados possam, pelo menos em parte, contribuir para o aparecimento de complica??es
16

Prospec??o e caracteriza??o de genes associados ao processo de indu??o floral em cana-de-a??car

Furtado, Cristiane Miranda 28 February 2007 (has links)
Made available in DSpace on 2014-12-17T15:18:12Z (GMT). No. of bitstreams: 1 CristianeMF.pdf: 69057 bytes, checksum: 86b55b192a6c5915d66e542325da022c (MD5) Previous issue date: 2007-02-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The northeastern region is responsible to 14.32% of sugarcane national production. This lowered contribution is due to edaphoclimatic condition. Flowering is a vital process to plant which consumes lots of energy and it culminates in a process called isoporization. This one can give in a decreasing of 60% on alcohol and water production. It may consider that cropped sugarcane has a hibrid with octaploid genome, there are varieties with a flowering standard until of non flowering. Using this natural genetic potential on different croppings of sugarcane, the aim of this work was to understand as this process occurs by the usage of subtractive approaches. The total RNA was extracted using Trizol of peaks of merisematics of croppings with induced flowering and other with late flowering. From this total RNA were built four subtractives libraries (B1- induced early flowering subtracted on late flowering not induced; B2- late flowering not induced subtracted induced early flowering; B3- induced early flowering subtracted of not induced early flowering; B02- not induced early flowering subtracted from induced early flowering) using kits Super Smart cDNA synthesis and BD Clontech kit select cDNA subtraction (Clontech). This material was clone don vector pGEM T-easy(Promega) and changed in competent cells of E.coli DH10B. Given analysis sequence was carried out a program BLASTn against database of NCBI and genome of Arabidopsis thaliana, rice and maize. Clones were grouped in 9 different classes according to function. Some factors already related as couples of flower induction were identified at different libraries. And grouped proteins with cell cycle and it controls were presents, mainly kinases proteins. Related factors to proteic sinthesis, metabolism, defence, cell communication were also given in both libraries .Some identified genes did not show similarity on database or homology with hypothesis function, and it can represents new genes to be deposited in international database. These results offers that some identified on sugarcane, classified as on factors classes, cell cycle and cell communication, trough unknown genes, can be linked with genetic changing to the flowering process found in the northeastern region / A regi?o nordeste ? respons?vel por 14,32% da produ??o nacional de cana-de-a??car. Esta contribui??o reduzida ? devido ?s condi??es edafo-clim?ticas da regi?o. A flora??o ? um processo vital para a planta que consome muita energia e culmina num fen?meno denominado de isoporiza??o do colmo. Esta isoporiza??o pode acarretar numa redu??o de at? 60% na produ??o de ?lcool e a??car. Considerando que a cana-de-a??car cultivada corresponde a um h?brido com o genoma octaploide, existem variedades com um padr?o de florescimento precoce at? um padr?o de n?o florescimento. Utilizando este potencial gen?tico natural presente nas diferentes cultivares de cana-de-a??car na regi?o nordeste, o objetivo do presente trabalho foi de compreender como ocorre esse processo de flora??o por meio da metodologia de bibliotecas subtrativas. O RNA total foi extra?do utilizando o reagente Trizol (Invitrogen) de ?pices meristem?ticos de cultivares com florescimento precoce induzida e n?o induzida e outra com florescimento tardio. A partir deste RNA total foram constru?das as quatro bibliotecas subtrativas (B1 florescimento precoce induzida subtra?da da tardia n?o-induzida; B2 florescimento tardio n?o-induzida subtra?do da precoce induzida; B3 precoce induzida subtra?da da precoce n?o-induzida; B02 precoce n?o-induzida subtra?da da precoce induzida), utilizando os kits Super Smart cDNA syntesis e o kit BD Clontech PCR select cDNA subtraction (Clontech). Este material foi clonado no vetor pGEM T-easy (Promega) e transformados em c?lulas competentes de E. coli DH10B. A an?lise das seq??ncias obtidas foi realizada utilizando o programa BLASTn contra o banco de dados do NCBI e do genoma de Arabidopsis thaliana, arroz e milho. Os clones foram agrupados em 9 diferentes classes de acordo com a fun??o. Alguns fatores de transcri??o j? relatados como participantes da via de indu??o floral foram identificados nas diferentes bibliotecas. Al?m disso, prote?nas associadas com o ciclo celular e seu controle tamb?m estavam presentes, destacando-se nesse grupo as prote?nas quinases. Fatores relacionados ? s?ntese prot?ica, metabolismo, defesa, transporte e comunica??o celular, tamb?m foram obtidos em ambas bibliotecas. Alguns genes identificados nas bibliotecas n?o apresentaram similaridade nos bancos de dados ou apresentaram homologia com genes de fun??o hipot?tica, e podem representar novos genes a serem depositados em bancos de dados internacionais. Estes resultados sugerem que alguns dos genes identificados em cana-de-a??car, classificados tanto na classe de fatores de transcri??o, ciclo celular e comunica??o celular, al?m dos genes n?o conhecidos, possam estar associados com a variabilidade gen?tica para o processo de flora??o encontrada na regi?o nordeste
17

Rela??o da express?o g?nica do ECHDC3 com perfil de ?cidos graxos e fatores nutricionais na doen?a arterial coronariana

Duarte, Mychelle Kytchia Rodrigues Nunes 06 December 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-21T18:51:09Z No. of bitstreams: 1 MychelleKytchiaRodriguesNunesDuarte_DISSERT.pdf: 2556724 bytes, checksum: 7d5fee1d4fe61eba6aa3c5ddd4fa6747 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-28T00:32:58Z (GMT) No. of bitstreams: 1 MychelleKytchiaRodriguesNunesDuarte_DISSERT.pdf: 2556724 bytes, checksum: 7d5fee1d4fe61eba6aa3c5ddd4fa6747 (MD5) / Made available in DSpace on 2017-03-28T00:32:58Z (GMT). No. of bitstreams: 1 MychelleKytchiaRodriguesNunesDuarte_DISSERT.pdf: 2556724 bytes, checksum: 7d5fee1d4fe61eba6aa3c5ddd4fa6747 (MD5) Previous issue date: 2016-12-06 / A doen?a arterial coronarina ? uma das principais causa de ?bitos em todo o mundo e pode ser desencadeada por altera??es no perfil s?rico de ?cidos graxos, nos padr?es de express?o g?nica, no consumo alimentar e diet?tico e por desequil?brios antropom?tricos e/ou de composi??o corporal. O diagn?stico precoce desta doen?a ? um desafio na medicina translacional, visto que os m?todos utilizados s?o onerosos e/ou invasivos. O trabalho ent?o teve como objetivo identificar biomarcadores para o diagn?stico precoce da aterosclerose por meio do perfil serico de ?cidos graxos, express?o do RNAm da enoil-coA-hidratase (ECDHC3) e de fatores nutricionais em pacientes sem les?es e com diferentes extens?es da les?o ateroscler?tica. Realizou-se um estudo observacional, com a amostragem coletada por conveni?ncia, formada por pacientes que iriam realizar pela primeira vez a cinecoronariogradia no setor de Hemodin?mica do Hospital Universit?rio Onofre Lopes. Na primeira casu?stica participam 59 pacientes (n1, 2011-2013) e na segunda 41 (n2, 2014-2015), ambos com idade entre 30-74 anos. Determinou-se a extens?o das les?es por meio do ?ndice de Friesinger, o perfil bioqu?mico (glic?mico,lipid?mico) por espectrometria semiautomatizado; concentra??o s?rica de ?cidos graxos pela cromatografia gasosa; express?o do RNAm do ECHDC3 pela rea??o de cadeia de prolimerase (PCR) em tempo real; consumo alimentar e diet?tico por dois recordat?rios de 24h, par?metros antropom?tricos e composi??o corporal pela balan?a com bioimped?ncia el?trica, fita m?trica e estadiometro. Os pacientes foram classificados em grupos: sem les?o (n1=18/n2 =8), poucas les?es (n1=17/n2=6), intermedi?rias (n1=17/n2=15) e graves (n1=7/n2=12). Na primeira casu?stica foi encontrado elevadas concentra??es s?ricas de ?cido ol?ico e de ?cidos graxos monoinsaturados nos pacientes com poucas les?es e intermedi?rias, quando comparado com pacientes sem les?o (p<0,05). A express?o do ECHDC3 foi 1,2 vezes mais alta em pacientes com poucas les?es que em pacientes sem les?o (p=0,023), e 1,8 vezes mais baixa em pacientes com les?o grave que em pacientes sem les?o (p=0,020). Na segunda casu?stica, a express?o do ECHDC3 foi 1,93 mais alta em pacientes com les?o intermedi?ria do que com poucas les?es (p = 0.011) e 1,91 vezes mais alta em pacientes com les?o grave que em poucas les?es (p = 0.013). A an?lise de Spearman mostrou uma correla??o entre os grupos de Friesinger com a express?o do ECHDC3 (r = 0.327, p =0.037) , e deste com o percentual de gordura visceral (r = 0.416, p =0.009). O ?ndice de Friesinger tamb?m mostrou uma correla??o com o consumo de carboidrato (r = 0.754, p = 0.002), vitamina B1 (r = 0.507, p = 0.001), vitamina B2 (r = 0.388, p = 0.012), folato (r = 0.599, p = 0.000) e magn?sio (r = 0.528, p = 0.003). Verificou-se que o aumento de ?cido ol?ico s?rico, da express?o do ECHDC3 e da gordura visceral podem contribuir para a progress?o da aterosclerose, uma vez que estes podem favorecer a ? ? oxida??o, rea??o que favorece a forma??o de esp?cies reativas de oxig?nio, desencadeando inflama??o, um dos principais gatilhos para a aterosclerose. Tamb?m foi visto que o consumo de carboidratos e alguns micronutrientes podem favorecer a progress?o da aterosclerose, j? que o aumento da ingest?o destes nutrientes pode propiciar a defici?ncia na absor??o ou estresse oxidativo, que implica diretamente na etiologia desta doen?a. / Coronary arterial disease is a at leading cause of death worldwide and can be triggered by alterations in the serum profile of fatty acids, by patterns of gene expression, changes in dietary intake, and alteration anthropometric. The early diagnosis of this pathophysiology is a challenge in translational medicine, since the methods used are expensive and / or invasive. The aim in the study was to identify biomarkers for the early diagnosis of atherosclerosis through the relationship of serum fatty acid profile, enoyl-coA hydratase (ECDHC3) mRNA expression and nutritional factors in patients without lesions and with different extensions of the atherosclerotic lesion. The study was observational, with the sample collected for convenience in two casuistry in the Hemodynamics sector of the Onofre Lopes University Hospital (HUOL). In the first series, 59 patients partipated (n1, 2011-2013) and in the second 41 individuals ( n2, 2014-2015), both aged 30-74 years and who were undergoing coronariography for the first time. The extent of atherosclerotic lesions was determined by Friesinger index, the biochemical profile by semi-automated spectrometry; the concentration of fatty acids by gas chromatography; gene expression of ECHDC3 mRNA by real-time PCR; food consumption and dietary intake for two 24-hour dietary intake recalls, anthropometric parameters and corporal composition by the electric bioimpedance, measuring tape and stadiometer scale.Patients were classified into groups: no lesion (n1 = 18 / n2 = 8), low lesions (n1 = 17 / n2 = 6), intermediate lesions (n1 = 17 / n2 = 15) and major lesion (n1= 7 / n2 = 12). In n1 was observed high serum concentrations of oleic acid and monounsaturated fatty acids in patients with low lesions and intermediate when compared to patients without lesions (p <0.05). ECHDC3 expression was 1.2 fold-higher in patients with low lesions than in patients without lesions (p = 0.023), and 1.8 fold- lower in patients with major lesions than in patients without lesions (p = 0.020). In the second casuistry, the expression of ECHDC3 was 1.93 fold-higher in patients with intermediate lesions than in low lesions (p = 0.011) and 1.91 fold-higher in patients with severe lesions than in low lesions (p = 0.013). Spearman's analysis showed a positive correlation showed a between ECHDC3 mRNA expression and Friesinger index (r = 0.327, p = 0.037), between the gene and visceral fat (r = 0.416, p = 0.009). The Friesinger index also showed a correlation with the consumption of carbohydrate (r = 0.754, p = 0.002), vitamin B1 (r = 0.507, p = 0.001), vitamin B2 (r = 0.388, p = 0.012), folate (r = 0.599, p = 0.000), magnesium (r = 0.528, p = 0.003). It was verified that oleic acid, ECHDC3 expression, percentage of visceral fat could favors ?-oxidation, trigger for inflammation and CVD; while the greater consumption of carbohydrate and some micronutrients, also could be associated with the CVD development, since the excess or decreased absorption can favors the oxidative stress, that favors the atherosclerosis.
18

Mieliniza??o cerebral p?s-natal em modelo de autismo induzido por exposi??o pr?-natal ao ?cido valpr?ico / Postnatal brain myelination in an animal model of autism induced by prenatal exposure to valproic acid

Sousa, Carolina Ara?jo 31 August 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-10-04T23:54:46Z No. of bitstreams: 1 CarolinaAraujoSousa_DISSERT.pdf: 4069494 bytes, checksum: 9b768a46fbe08e2407ed147faed6bc74 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-10-16T20:38:12Z (GMT) No. of bitstreams: 1 CarolinaAraujoSousa_DISSERT.pdf: 4069494 bytes, checksum: 9b768a46fbe08e2407ed147faed6bc74 (MD5) / Made available in DSpace on 2017-10-16T20:38:12Z (GMT). No. of bitstreams: 1 CarolinaAraujoSousa_DISSERT.pdf: 4069494 bytes, checksum: 9b768a46fbe08e2407ed147faed6bc74 (MD5) Previous issue date: 2017-08-31 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / A forma??o de circuitos neurais durante o desenvolvimento se d? atrav?s de uma complexa intera??o entre fatores gen?ticos e ambientais, que influenciam m?ltiplos eventos como a neurog?nese, a sinaptog?nese e a mieliniza??o. Em transtornos do desenvolvimento, como o transtorno do espectro autista (TEA), intercorr?ncias nesse processo levam ? m?-forma??o da circuitaria neural e, consequentemente, a d?ficits de intera??o social, interesses restritos e movimentos estereotipados, entre outros. Recentemente, realizamos em nosso laborat?rio a an?lise do transcriptoma do c?rtex frontal no modelo animal de autismo induzido por exposi??o a ?cido valpr?ico (VPA) in utero. Observamos que ratos com 15 dias de idade (P15) apresentam aumento da express?o de genes relacionados ? estabilidade sin?ptica e redu??o de genes relacionado ? mielina, sugerindo poss?veis mecanismos moleculares para as varia??es comportamentais previamente observadas nestes animais. Portanto, o objetivo desta disserta??o foi aprofundar este estudo investigando o padr?o de mieliniza??o no enc?falo de animais tratados com VPA em diferentes idades p?s-natais (infantil: P15 e adulta: P60). Para tanto, os grupos experimental e controle foram gerados, respectivamente, atrav?s da inje??o de VPA (500 mg/kg i.p.) ou salina em f?meas gr?vidas durante o dia embrion?rio 12.5 (E12.5). A an?lise da integridade da mielina foi realizada por duas abordagens: (1) an?lise da express?o de genes relacionados ? mielina (Mobp, Plp1, Mag e Klhl1), por PCR quantitativo, no c?rtex frontal de animais em P15; e (2) quantifica??o histol?gica da distribui??o de mielina em cinco sub-regi?es do c?rtex frontal e corpo caloso de animais P15 e P60. Dos quatro genes avaliados, observamos significativa diminui??o na express?o de Mobp e Mag em animais VPA em P15. A an?lise histol?gica de mielina mostrou redu??o significativa na intensidade de marca??o no c?rtex cingulado anterior em animais VPA em P60, por?m n?o detectou diferen?a na intensidade de marca??o em animais VPA em P15 quando comparados aos controles. Conclu?mos assim que animais VPA neonatos t?m reduzida express?o de genes relacionados a compacta??o da mielina, por?m sem altera??es no conte?do lip?dico da mielina nas ?reas analisadas. Animais adultos, por sua vez, apresentaram altera??es no conte?do lip?dico da mielina no c?rtex cingulado anterior. Em conjunto, estes resultados sugerem que dist?rbios na comunica??o entre circuitos frontais neste modelo de autismo podem ocorrer inicialmente devido altera??es na organiza??o da mielina, levando a redu??es de mielina no adulto. / The formation of brain circuits during neural development occurs through the interaction between timely regulated genetic and environmental signals, which influence multiple events such as neurogenesis, synaptogenesis, and myelination. In developmental disorders, such as autism spectrum disorders (ASD), deficits in these processes may lead to neural circuitry malformations and, in consequence, to social interaction deficits, restricted interests, and stereotyped movements, among others. Recently, we performed a transcriptome analysis of the frontal cortex of an animal model of autism induced by valproic acid (VPA) in utero in our lab. We observed that VPA animals at the postnatal age 15 (P15) show an increased expression of genes related to synaptic stability and a decrease in the expression of myelin-related genes, suggesting possible molecular mechanisms for the behavioral deficits previously observed in these animals. Therefore, the aim of this Master?s thesis was to further investigate the myelination pattern in the forebrain of VPA-treated rats at different postnatal ages (infant: P15 and adult: P60). For that, experimental and control groups were generated by injecting pregnant dams with 500 mg/Kg i.p. VPA or saline, respectively, on embryonic day 12.5 (E12.5). Analysis of myelin integrity was conducted by two different approaches: (1) gene expression analysis of myelin-related genes (Mobp, Plp1, Mag, and Klhl1) in dissected samples of the frontal cortex of P15 rats by quantitative real-time PCR; and (2) histological quantification of myelin distribution in five sub-regions of the frontal cortex and corpus callosum of P15 and P60 animals. Of all genes analyzed, we observed a significant decrease in Mobp and Mag expression in P15 VPA animals. Myelin analysis showed a significant reduction in myelin staining in the anterior cingulate cortex of VPA animals at P60, but no differences were observed at P15. In conclusion, infant VPA rats showed reduced expression of genes related to myelin assembly, without alterations in the lipid content of myelin in the areas analyzed. Adult animals, in contrast, showed a decrease in lipid content of myelin in the anterior cingulate cortex. Together, these results suggest that communication abnormalities in frontal circuits in this animal model of autism may occur initially due to alterations in myelin organization, leading to myelin reduction in adulthood.
19

Efeito da superexpress?o dos fatores de transcri??o ZmDof1 e OsDof25 sobre a efici?ncia de uso de nitrog?nio em Arabidopsis. / Effects of ZmDof1 and OsDof25 transcriptional factors superexpression on nitrogen usage efficiency in Arabidopsis.

Santos, Leandro Azevedo 03 June 2009 (has links)
Made available in DSpace on 2016-04-26T19:39:32Z (GMT). No. of bitstreams: 1 2009 - Leandro Azevedo Santos.pdf: 3069700 bytes, checksum: dbd1726a5b683e7f290e1829143eacac (MD5) Previous issue date: 2009-06-03 / Funda??o Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / To improve nitrogen usage efficiency in plants the rice transcriptional factor OsDof25 was identified and cloned, whose probably orthologe is the maize ZmDof1, already identified and partially characterized. The ZmDof1 was also cloned for comparative analysis with OsDof25, in order to confirm this last one as ZmDof1 orthologe in rice. The constructions for Arabidopsis superexpression of these transcriptional factors were made using the cloning system of gateway technology (Invitrogen), to obtain the expression vectors 35S:ZmDof1:HA and 35S:OsDof25:HA. Lineages with different expression levels of these genes were obtained, but with only one inserted copy. These transgenic lineages when grown in a half strength of MS medium (10mM of NH4 + and 20mM of NO3 -) showed phenotypes with chloroses and growth difficulty; although when they were cultured in soil they showed great vegetative development and delay in the inflorescence emission. When analyzed the gene expression changes induced by the superexpression of these transcriptional factors, it was observed that both genes produced an increase in the expression levels of high and low affinity ammonium transporters (AMT1.1 and AMT2.1, respectively), indicating that these phenotypes may be due to the toxic effect of an excess of ammonium uptake. We also verified an increase of expression for pyruvate kinase (PK1 and PK2), and phosphoenolpyruvate carboxylase (PEPC1 and PEPC2). Pyruvate kinase converts phophoenolpyruvate (PEP) to pyruvate, and phosphoenolpyruvate carboxylase converts PEP to oxalacetate, which is substrate for malate dehydrogenase to form malate. Both pyruvate and malate may feed the Krebs cycle. In addition, there was an increase in the expression of isocitrate dehydrogenase, which is present in the citosol and mitochondria, needed for converting isocitrate to 2- oxoglutarate. Thus, it was hypothesized that the increase of expression levels of these carbon metabolism enzymes was necessary to increase the production of 2-oxoglutarate and, consequently, to reduce the toxic effect of ammonium uptaked. Besides, it was observed an increase of expression levels and activity of glutamate dehydrogenase (GDH). This enzime may work as much in the direction of glutamate amination as in deamination, when the plants were submitted to ammonium excess or carbon limitation conditions, respectively. / Com o objetivo de aumentar a efici?ncia de uso de nitrog?nio (EUN) em plantas, foi identificado e clonado o fator de transcri??o OsDof25 de arroz, cujo prov?vel ort?logo ? o ZmDof1 de milho, j? identificado e parcialmente caracterizado. Tamb?m foi clonado o ZmDof1 para an?lises comparativas com o OsDof25, a fim de comprovar que este ?ltimo ? realmente ort?logo do ZmDof1. As constru??es para superexpress?o destes fatores de transcri??o em Arabidopis foram feitas utilizando o sistema gateway de clonagem para obten??o dos vetores de express?o 35S:ZmDof1:HA e 35S:OsDof25:HA. Foram obtidas linhagens com diferentes n?veis de express?o destes genes, mas com apenas uma inser??o. As linhagens transg?nicas obtidas quando crescidas em meio MS ? for?a i?nica (10mM de NH4 + e 20mM de NO3 -) apresentaram fen?tipos como clorose e dificuldade de desenvolvimento, ao passo que quando cultivadas em solo mostraram desenvolvimento vegetativo mais intenso e atraso para emiss?o da infloresc?ncia. Quando analisadas as modifica??es de express?o g?nica causadas pela superexpress?o destes fatores de transcri??o, observou-se que ambos os fatores de transcri??o provocaram aumento de express?o dos transportadores de am?nio de alta e baixa afinidades (AMT1.1 e AMT2.1 respectivamente), indicando que o fen?tipo observado pode ser devido ao efeito t?xico do excesso de am?nio absorvido. Verificou-se tamb?m aumento de express?o das enzimas piruvato quinase (PK1 e PK2) e fosfoenolpiruvato carboxilase (PEPC1 e PEPC2). A piruvato quinase converte o fosfoenolpurato (PEP) a piruvato, enquanto a fosfoenolpiruvato carboxilase converte o PEP a oxalacetato (OAA) que pode sofrer a??o da malato desidrogenase originando o malato. Ambos os metab?litos, piruvato e malato, alimentam o ciclo de Krebs. Houve tamb?m aumento de express?o da isocitrato desidrogenase, enzima presente na mitoc?ndria (ciclo de Krebs) e no citosol que converte isocitrato a 2-oxoglutarato (2-OG). Assim, ? prov?vel que o aumento da express?o destas enzimas do metabolismo de carbono foi necess?rio para aumentar a produ??o de 2-OG e, por conseguinte, diminuir o efeito t?xico do excesso de am?nio absorvido. Al?m disso, observou-se aumento de express?o e atividade da glutamato desidrogenase (GDH). Essa enzima pode atuar tanto na dire??o da amina??o, quanto na dire??o da desamina??o, em condi??es de excesso de am?nio e/ou sob condi??es de limita??o de carbono nas plantas, respectivamente.

Page generated in 0.048 seconds