O presente trabalho analisou as etapas de formação de rudimentos seminais e grãos de pólen de Passiflora elegans e P. haematostigma. As espécies foram analisadas fazendo-se o uso de microscopia fotônica e microscopia eletrônica de varredura e transmissão. O gineceu apresenta um estigma com emergências estigmáticas, estilete sólido e ovário tricarpelar e unilocular. O ovário apresenta inúmeros rudimentos seminais que formam-se a partir de divisões periclinais da camada central. Os rudimentos são crassinucelados e os tegumentos têm origem dérmica. A célula arquesporial divide-se mitoticamente antes da meiose. A meiose resulta em uma tétrade linear, com ginósporo calazal viável. A ginogametogênese é do tipo Poligonum e, durante a diferenciação do ginófito, os estratos parietais do nucelo são parcialmente consumidos e a epiderme nucelar divide-se periclinalmente na porção apical. As antípodas são efêmeras e o ginófito maduro apresenta duas sinérgides com aparelho fibrilar desenvolvido, oosfera e núcleo secundário no pólo micropilar. O rudimento seminal é anátropo, arilado, bitegumentado e com micrópila em “zig-zag”. O androceu é constituído por cinco anteras tetrasporangiadas. Os estratos parietais desenvolvem-se do tipo Dicotiledôneo e as camadas médias são persistentes na antera madura de P. haematostigma. As células do tapete são poliplóides e colapsam liberando os conteúdos no interior do lóculo. A citocinese é do tipo simultânea e as tétrades são tetraédricas na maioria. O pólen é liberado na fase bicelular, apresenta número de colpos variável em P. elegans e seis colporos em P. haematostigma. A esporoderme não apresenta camada basal em P. elegans e é mais espessa do que em P. haematostigma. Plastídios e mitocôndrias são englobados durante a formação da célula generativa e persistem até a fase de pólen maduro. / The present work analyzed the different developmental stages of the ovule and of the pollen grain in Passiflora elegans and P. haematostigma. The species were analyzed using photonic microscopy and scanning and transmission electron microscopy. The gynoecium has a stigma with stigmatic outgrowths, solid style and tricarpelar and unilocular ovary. The ovary has several seminal rudiments that are originated from the periclinal divisions of the central layer. The ovule is crassinucelate and the dermal layer originates the integuments. The arquesporial cell divides mitotically before meiosis. The meiosis results into a linear tetrad and only the chalazal gynospore is viable. The gynogametogenesis is of the Poligonum type, the nucellus parietal layers are partially degraded during the gynophyte differentiation, and nuclear epidermis divides periclinally in the apical portion. The antipodal cells are ephemeral and the mature gynophyte has two synergids with a developed filiform apparatus, egg cell and secondary nuclei in the micropilar pole. The ovule is anatropous, arillate, bitegmic and with zig-zag micropile. The androecium is constituted of five tetrasporangiate anthers. The parietal layers develop like the Dicotiledoneous type and middle layers are persistent in the mature anther of P. haematostigma. The tapetal cells are polyploids and collapse releasing their contents to the locus. The cytokinesis is of the simultaneous type and most of the tetrads are tetrahedral. The pollen is released during the bicellular stage, has a variable number of colpus in P. elegans and six colporus in P. haematostigma. The sporoderm does not have a basal layer in P. elegans and is thicker than in P. haematostigma. Plastids and mitochondria are enclosed during the generative cell formation and persist until the mature pollen stage.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-21T15:38:16Z No. of bitstreams: 1 Agna Rita dos Santos Rodrigues.pdf: 1761082 bytes, checksum: 33ad0d0702f86a28c68a0fe70066f3f7 (MD5) / Made available in DSpace on 2016-11-21T15:38:16Z (GMT). No. of bitstreams: 1 Agna Rita dos Santos Rodrigues.pdf: 1761082 bytes, checksum: 33ad0d0702f86a28c68a0fe70066f3f7 (MD5) Previous issue date: 2012-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Insecticides and natural enemies are used or preserved sharing the same objective of reducing pest populations in the crop ecosystems. However, the examples of simultaneous action with additive or synergistic outcomes are rare. The resistance in lady beetles to the insecticide lambda-cyhalothrin, which is widely used against pests nontarget of the lady beetles, can result in simultaneous use of chemical and at least partial biological control. In this study was investigated the susceptibility of 28 Brazilian and 2 North American lady beetle populations to the lambda-cyhalothrin. Furthermore, studies were conducted to characterize the mechanisms and the inheritance of resistance for those species exhibiting high levels of tolerance to lambda-cyhalothrin. Among the studied populations resistance ratios were determined varying from 115- to 38-fold in four populations of Eriopis connexa Germar and 220-fold in one North American population of Hippodamia convergens Guérin-Méneville; therefore, there is strong evidence for selection of resistance to lambda-cyhalothrin in the field. Further, 22 and 96% of the Brazilian populations exhibited LD50 value that exceed the recommended lambda-cyhalothrin dose to spray cotton fields and the LD50 calculated for boll weevil (Anthonomus grandis Boh.). The lady beetle E. connexa exhibited autosomal and incompletely dominant inheritance of resistance to lambda- cyhalothrin; while the knockdown effect for H. convergens was sex linked and incompletely recessive. The tests indicated polygenically inherited resistance for both species with effective dominance varying as function of the dose applied. Resistance in E. connexa was completely inhibited with piperonyl butoxide (PBO), while the resistance in H. convergens was only partially inhibited with this synergist. High level of esterase activity was found in the resistant population of E. connexa. These results show the first record of resistance for lady beetles in Brazil and the first characterization of inheritance of resistance and metabolism related to insecticide resistance in lady beetles in the world. / Inseticidas e inimigos naturais são empregados nos agroecossistemas dividindo o mesmo objetivo de reduzir populações de pragas. No entanto, raros são os exemplos da ação simultânea com resultados aditivos ou sinergistas de controle. A resistência em joaninhas ao lambda-cialotrina, produto utilizado para o controle de pragas não alvo das joaninhas, pode resultar em uso simultâneo do controle biológico e químico. Assim, neste estudo foi investigada a suscetibilidade de 28 populações brasileiras de oito espécies de joaninhas e duas populações de joaninhas norte americanas ao inseticida lambda-cialotrina, bem como a caracterização dos mecanismos e herança da resistência em espécies com alto grau de tolerância. Entre as populações e espécies estudadas foram determinadas razões de resistência variando de 11- a 38-vezes em quatro populações de Eriopis connexa Germar e de 220-vezes para a população americana de Hippodamia convergens Guérin-Méneville, sendo assim consideradas como selecionadas em campo para resistência ao lambda-cialotrina. Além disso, baseado na DL50 de sete espécies estudadas com ocorrência natural em algodoeiro, 22 e 96% das populações foram mais tolerantes à maior dose recomendada do lambda-cialotrina para uso na cultura do algodão e a DL50 estimada para Anthonomus grandis Boh., respectivamente. A população estudada de E. connexa possui herança da resistência autossomal e incompletamente dominante, enquanto que a resistência knockdown em H. convergens é ligado ao sexo e incompletamente recessiva. Os testes indicaram herança poligênica para E. connexa. Para E. connexa e H. convergens, a dominância efetiva variou em função da dose utilizada. O butóxido de piperonila (PBO) inibiu completamente o metabolismo do lambda-cialotrina em E. connexa, tornando a população resistente similar a população suscetível, enquanto que em H. convergens, o metabolismo foi apenas parcialmente inibido por este sinergista.Vale ressaltar que foi observada alta atividade de esterases na população resistente de E. connexa. Estes resultados compõem o primeiro relato de resistência de joaninhas à inseticida no Brasil e a primeira caracterização da herança e metabolismo quanto à resistência de joaninhas no mundo.

As ataxias hereditárias autossômicas recessivas compõem um grupo de doenças heterogêneas, que necessitam de criteriosa avaliação clínica, de exames complementares e, algumas vezes, de testes genéticos para o diagnóstico. A partir da revisão da literatura, foi elaborado um algoritmo para auxiliar a investigação diagnóstica deste grupo. Esta tese tem como objetivo apresentar os resultados da investigação de três formas de ataxias recessivas: 1. Síndrome de Joubert, caracterizada por hipotonia precoce, atraso do desenvolvimento neuropsicomotor, ataxia e padrão respiratório irregular no período neonatal ou anormalidades na motricidade ocular extrínseca. Apresenta amplo espectro clínico, assim como heterogeneidade genética. Alterações renal, hepática e da retina são freqüentes. A presença de hipoplasia do vermis cerebelar, alongamento dos pedúnculos cerebelares superiores e aumento da fossa interpeduncular, aos cortes axiais da ressonância magnética (RM) do encéfalo, constituem o sinal do dente molar, considerado critério radiológico obrigatório para o diagnóstico. Aqui é apresentada uma série de cinco pacientes que preenchem critérios clínicos e radiológico de síndrome de Joubert e tem grande variabilidade fenotípica: duas crianças têm a forma pura (subtipo 1), uma tem associadamente retinopatia (subtipo 3), uma tem amaurose congênita de Leber e alteração renal (subtipo 4) e a outra apresenta associadamente coloboma corioretiniano e alterações hepáticas (subtipo 5); 2. Ataxia com Deficiência de Vitamina E, que apresenta fenótipo semelhante ao da ataxia de Friedreich, progressão mais lenta, baixo nível sérico de -tocoferol e é tratável com reposição da vitamina E. Frequente no sul da Itália e norte da África, sem relatos no Brasil. Foram investigados quatro pacientes pertencentes a duas famílias: três apresentavam o quadro clínico típico acompanhado de distonia em mãos, manifestação pouco relatada, mas que pode contribuir para a diferenciação clínica com ataxia de Friedreich. O outro paciente foi identificado em fase pré-sintomática, após o diagnóstico ser estabelecido em dois irmãos, e permanece com sinais sutis de alteração do equilíbrio após de 5 anos de reposição de vitamina E. Nos demais, a reposição de vitamina E promoveu melhora dos sintomas e impediu que a doença se agravasse; 3. Xantomatose Cerebrotendínea, que está relacionada à alteração no metabolismo do colesterol, com redução na produção dos ácidos biliares e acúmulo de colestanol, um metabólito tóxico. Catarata congênita ou juvenil e diarréia crônica são manifestações precoces. Ataxia cerebelar, paraparesia espástica, declínio cognitivo e xantomas tendíneos completam o quadro clínico. Na RM do encéfalo, a presença de hipersinal nos núcleos denteados, nas sequências T2-pesada e FLAIR, é sugestiva da doença. Três pacientes, pertencentes a duas famílias, com alterações clínicas e radiológica foram investigados. Em todos, o colestanol sérico encontravase elevado. A espectrocopia por RM detectou no cerebelo pico em 1,2-1,4 ppm, sugestivo de lipídio, achado até o momento não descrito. Após início do tratamento com ácido quenodeoxicólico, observou-se melhora da marcha. / Autosomal recessive hereditary ataxias belong to a group of heterogeneous disorders, for which detailed clinical evaluation, ancillary exams, and sometimes, genetic tests, are required for diagnosis. After literature review, an algorithm was built to help the investigation of this group. The objective of this thesis is to present the results of investigation of three forms of recessive ataxias: 1. Joubert syndrome is a condition characterized by early hypotonia, developmental delay, ataxia and neonatal respiratory disturbances or abnormal eye movement. It has a wide clinical spectrum and is genetically heterogeneous. Renal, hepatic and retina abnormalities are often seen. A combination of midline cerebellar vermis hypoplasia, deepened interpenducular fossa, and thick, elongated superior cerebellar penduncles gives to the axial view of the midbrain an appearance of a molar tooth at brain magnetic ressonance image (MRI) study. Molar tooth sign is considered as obligatory radiologic criteria to diagnosis. In this study we present a series of five patients that have clinical and radiologic criteria to Joubert syndrome and a large phenotypic variability: Two children have a pure form (subgroup 1), one child has an associated retinopathy (subgroup 3), the other has Leber congenital amaurosis and kidney abnormalitties (subgroup 4), and another has chorioretinal coloboma and hepatic abnormalities (subgroup 5); 2. Ataxia with vitamin E deficiency, which has a phenotype similar to Friederich ataxia but slowest progression, is characterized by low levels of serum -tocopherol and is treatable with vitamin E. This ataxia is common in South Italy and North Africa, but was not reported in Brazil. Four patients from two different families were studied. Three of them have typical clinical features and hands dystonia, a probably underreported feature which might helps its distinction from Friedreich ataxia. The other case was identified in a presymptomatic stage, after family investigation. After five years of treatment with vitamin E, subtle balance disturbance was still present. The remaing three patientes improved with vitamin E supplementation and disease progression stopped; 3. Cerebrotendinous xantomathosis (CTX) is a disorder of cholesterol metabolism, characterized by reduction of bile acid synthesis and accumulation of cholestanol, a toxic metabolic. Congenital or juvenile cataract and chronic diarrhea are early manifestations. Cerebellar ataxia, spastic paraplegia, cognitive impairment and tendinous xanthomas are also seen. Brain MRI T2-weighted and FLAIR sequences disclosed dentate nucleus hypersignal, a quite feature in CTX. Three patients from two different families, with clinical and radiologic features were studied. In all, serum cholestanol was elevated. MRI spectroscopy demonstrated in cerebellum a peak in 1,2-1,4 ppm, which is an possibly a lipid, not previously described. Treatment with chenodeoxycholic acid improved their gait.

Informações sobre a herança de caracteres relacionados à eficiência e resposta ao P em milho, obtidas em ensaios conduzidos até a maturação em ambientes tropicais são limitadas, sendo prérequisitos para se estabelecer estratégias de seleção eficientes. O objetivo deste trabalho foi estudar a herança e as relações entre caracteres de eficiência e resposta ao P em milho tropical. Foram utilizadas seis linhagens e sete F1´s entre elas, contrastantes quanto à sua eficiência ao P. Os genitores, F1´s, F2´s, RC1P1, RC1P2, RC2P1 e RC2P2 de cada um dos sete F1´s, foram avaliados em três ambientes sob baixo P, e dois ambientes sob alto P no solo. Caracteres de eficiência avaliados foram: peso de grãos (PG), teor de P nos grãos (TPG), quantidade P total na parte aérea (FTOT), eficiência de absorção (EFABS), de utilização (EFUTIL), e de uso de P(EFUSO), índice de colheita de P (ICP) e quociente utilização (QUTIL). Caracteres de resposta avaliados foram: diferença PG entre níveis de P (DIFPG), relação PG entre baixo e alto P (RELPG), eficiência recuperação aparente (EFREC), eficiência fisiológica (EFIS) e eficiência agronômica (EFAGR). Foi também avaliado o intervalo entre florescimento masculino e feminino (ASI), que tem sido relacionado à tolerância a estresse de seca. As médias das gerações de cada cruzamento foram utilizadas para estimar o efeito médio (m), efeitos aditivos (a), efeitos de dominância (d) e efeitos epistáticos digênicos (aa, ad e dd) sob baixo e alto P no solo. Deficiência de P causou redução média na produção de 47,10%. Efeitos de dominância, seguidos de efeitos epistáticos (quando detectados) foram superiores aos efeitos aditivos para a maioria dos caracteres estudados. O ambiente afetou a herança dos diversos caracteres e estimativas de dominância para PG foram de maior magnitude nos ambientes sob alto P e efeitos epistáticos foram verificados com maior freqüência, nos ambientes sob baixo P no solo. Quanto à variabilidade observada para eficiência de uso de P, EFABS foi duas a três vezes mais importante que EFUTIL sob baixo e alto P respectivamente, indicando que, processos relacionados à absorção de P em milho, foram mais importantes que àqueles relacionados à utilização interna do P na planta, nos ambientes estudados. EFABS mostrou baixa correlação sob baixo e alto P, sugerindo que diferentes mecanismos de aquisição de P podem estar atuando nestes ambientes. EFUTIL mostrou alta correlação entre ambientes sugerindo que mecanismos de utilização interna de P semelhantes podem estar agindo sob baixo e alto P. ASI mostrou correlação média e negativa com PG sob baixo P. Critérios de seleção mais adequados para os diversos componentes de eficiência e resposta ao P seriam: PG sob baixo P no solo para determinar a EFABS nestes ambientes; baixo teor de P nos grãos obtido sob alto P no solo, para determinar a EFUTIL; DIFPG para determinar a resposta ao P; menores valores de ASI sob baixo P como critério auxiliar de seleção. Correlações entre variáveis de eficiência e resposta ao P indicaram ser viável obter genótipos eficientes e responsivos ao P nas condições deste estudo. / Low information is available concerning the inheritance of phosphorus (P) efficiency and responsiveness in tropical maize, obtained from trials conducted until maturity in tropical environments. This information is the basis to establish selection strategies for these characteristics. The objective of this study was to investigate the inheritance and relationships between characteristics related to phosphorus efficiency and responsiveness in tropical maize. Six tropical maize lines with contrasting P use efficiency and seven F1´s derived from them were used. The parental lines, F1´s, F2´s, RC1P1, RC1P2, RC2P1 e RC2P2 from each of the seven crosses were evaluated at three low P and two high P environments. Efficiency traits evaluated were: grain weight (GW), grain P concentration (GPC), total P in the shoot (PTOT), P uptake efficiency (PUPE), P internal utilization efficiency (PUTIL), P use efficiency (PUE), P harvest index (PHI) and quotient of utilization (QUTIL). Responsiveness traits evaluated were: grain difference between high and low P environments (DIFGW), ratio GW of low and high P environments (RGW), P apparent recover (PAR), P physiological efficiency (PFIS) and P agronomic efficiency (PAGR). Anther silk interval (ASI), which has been related to drought tolerance, was also determined. The generation means from each cross in each group of environments (low and high soil P) were used to estimate the parameters mean effect (m), additive effects (a), dominant effects (d) and epistatic digenic effects (aa, ad, dd). A 47,10 % mean yield reduction was observed across soil P levels. Dominance effects, followed by epistatic effects (when detected) were more important than additive effects for the majority of the traits studied. Soil P level affected the inheritance of many traits. Dominance estimatives for GW were higher at high P environments than at low P environments and generally,epistatic effects were detected more frequently at low P environments. The component PUPE showed to be two to three times more important than the component PUTIL for the variability observed for P use efficiency under low and high P environments respectively, indicating that mechanisms related to P acquisition were more important than mechanisms related to P internal utilization efficiency in the environments and genotypes studied. PUPE showed low correlation under low and high P environments, suggesting that different mechanism of soil P acquisition should be acting at these environments. PUTIL showed high correlation under low and high P environments suggesting that similar plant internal mechanisms should be acting at low and high P environments. A mediun and negative correlation was observed between ASI and GW at low P environments. Selection criteria that showed to be more adequate to select for P efficiency and responsiveness were: GW under low P environments to determine PUPE under low P soils; grain P concentration under high P environments to determine PUTIL; DIFGW to determine P responsiveness and short ASI at low P environments as an additional selection criteria. Correlations between efficiency and responsiveness traits indicated that it would be possible to obtain efficient and responsive genotypes in the conditions of this study.

The technique of Object Oriented Analysis (OOA) has emerged only in the last decade. Although the technique of OOA is still new, its popularity has been increasing and it has already entered the mainstream of object oriented system development. This thesis makes a summary of four OOA methods and investigates the behaviors of all methods under different criteria. Through comparing the four methods, differences between methods are shown and analysts can select the appropriate one to meet his/her requirements. / Polhemsgatan 27A 37140 Karlskrona Sweden Huanday@hotmail.com

Cette thèse interroge le concept d’hérédité biologique, ses récentes mutations et leur incidence sur la théorie synthétique de l’évolution, qui est fondée sur une vision strictement génétique de la variation héritable. Elle propose une clarification conceptuelle à l’heure où une abondante littérature décrit des mécanismes de transmission qui défient la théorie génétique et où l’extension du champ de l’héréditaire pourrait modifier le regard des biologistes sur les processus évolutifs. Revenant sur l’histoire d’une notion introduite dans les sciences du vivant en tant que métaphore et associée dès le XIXe siècle à une réflexion sur l’évolution biologique, notre travail de recherche examine la façon dont le concept d’hérédité a été modelé au XXe siècle par la génétique et intégré dans les travaux des biologistes de l’évolution. Il offre une synthèse des données relatives à l’hérédité non génétique et étudie un ensemble de critères nécessaires à l’élaboration d’un concept d’hérédité à la fois inclusif, cohérent et théoriquement fécond. La thèse développe une analyse critique des cadres conceptuels «inclusifs» existants avant de présenter les fondements d’une perspective organisationnelle originale. Dans cette perspective, l'hérédité apparaît comme un phénomène de récurrence transgénérationnelle de variations dans des patrons organisationnels partagés. Elle est sous-tendue par la reconstruction d’éléments génétiques et non génétiques constitutifs (vs. environnementaux). La perspective organisationnelle développée dégage quelques pistes de réflexion pour penser l’incidence d’une hérédité plurielle sur les dynamiques évolutives. / This essay questions the concept of biological inheritance, its recent transformations and their potential impact on the theory of evolution, which is grounded on a genetic vision of heritable variation. It proposes a conceptual clarification while an abundant literature highlights various mechanisms of transmission that challenge the genetic theory of inheritance, and while the extension of the field of inheritance could modify the perspectives of evolutionary biologists on evolutionary processes. This work goes back to the history of a notion introduced in the life sciences as a metaphor and associated, since the 19th century, with concerns about biological evolution. It describes how the concept of biological inheritance was designed by genetics (Mendelian and molecular) during the 20th century and how it was integrated into the studies of evolutionary biologists. It presents data regarding non-genetic inheritance, underlines the necessity to make a selection among them and proposes criteria necessary to the construction of an inclusive, consistent and theoretically fecund concept of biological inheritance. It offers an analysis of existing inclusive conceptual frameworks and offers some foundations for an original organizational perspective. The perspective describes inheritance as a phenomenon of trans-generational reoccurrence of variation in shared organizational patterns underpinned by the reconstruction of genetic and non-genetic constructive elements (vs. environmental). The organizational perspective developed in the essay provides original considerations regarding the impact of a multidimensional inheritance on evolutionary dynamics.

The thesis includes the analysis of the fideicommissum institute, which is one of the elements of the Czech Inheritance Law that were reintroduced into the new Czech Civil Code, which came into effect on the 1st of Janurary 2014. The theme is highly actual due to the new important possibilities of expressing the will of the testator for the occasion of his death. The thesis is focused on the analysis of the current enactment and describes the historic development of the fideicommissum institute The text contains four fundamental parts. The first presents the fideicommissum institute and its role and development in the Inheritance Law from the time of Roman Law. The author deals in this chapter with the intertemporal provisions and other coherent institutes, which go along with the fideicommissum institute. We talk about hereditas iacens and administration of the inheritance. In the next chapter, the author explains the current enactment in the Civil Code in detail and mentions the procedural enactment of the special Code on Specific Civil Proceedings as well. It consists of the foundation of the fideicommissum and the inheritance regime. The last chapter consists of comparison of the Czech and Slovak enactment. Taking into account that in the Slovac Republic is currently being prepared the new...

This thesis deals with changes in the scope of autonomy of the devisor's will in the period from 1 January 1812 until the present days. Using the descriptive and analytical method and comparative method, the aim of this thesis is to explicate development of individual institutes of the law of succession, by means of which the devisor could or in particular can manifest his/her autonomy. This thesis is divided into five main parts, which are further divided into chapters and subchapters. The first part of the thesis represents an introductory excursus to the issue of the law of succession and the stress is put on basic principles of the law of succession and historical development thereof. The second part deals with manifestations of autonomy of the devisor's will under effectiveness of ABGB. Attention is paid to individual institutes of the law of succession and development thereof, special part deals with a testament as the most important manifestation of the freedom of disposition. Interpretation of individual institutes is presented in particular in the light of the comments and judicature of the period of the First Czechoslovak Republic. The third part deals with manifestations of autonomy of the devisor's will under effectiveness of the Civil Code of 1950. The third part endeavors to describe...

This thesis deals with the fideicommissary substitution that has made a reappearance in the civil law of the Czech Republic after fifty years. This change came into effect on the 1st of January 2014, along with a newly effective and modernized Civil Code. The purpose of this thesis is to analyze the reasons for the reintroduction of the fideicommissary substitution into the Czech inheritance law. The thesis is divided into three main sections. The first section focuses on the definition of the fideicommissary substitution. The fideicommissary substitution is also compared to other similar institutions of the Czech inheritance law. The second section focuses on the origins of the fideicommissum in Roman law and its alterations throughout the history, with the emphasis on its adaptations in the Civil Codes effective on the territory of the current Czech Republic. The last section focuses on comparing the institution of the fideicommissary substitution to similar institutions in France, Germany, Spain and Scotland in order to demonstrate the differences and similarities among them.

The membrane system of a eukaryotic cell is a large and complex system handling the transport, exchange and degradation of many kinds of material. Recent research shows that double-stranded RNA (dsRNA) mediated gene silencing (RNA interference) is a membrane related process. After long dsRNA is processed to small interfering RNA (siRNA) by Dicer, the guide strand and passenger strand are separated in the RNA induced silencing complex (RISC) by Argonaute. The process of loading siRNA into RISC has been suggested to occur at the rough Endoplasmic Reticulum (rER).The components of RISC also associate with late endosomes/multivesicular bodies (MVBs). Furthermore, disturbing the balance between late endosomes/MVBs and lysosomes has been shown to affect the efficiency of silencing. We use the nematode Caenorhabditis elegans as our model organism to study two questions: how does membrane transport affect RNAi and spreading of RNAi from the recipient cells to other tissues (systemic RNAi); and how does RNA transport contribute to the multigenerational silencing induced by dsRNA (RNAi inheritance)? Using SID-5, a protein required for efficient systemic RNAi, as bait in a yeast two-hybrid (Y2H) screen, we got 32 SID-5 interacting candidate proteins. Two of these are the SNARE protein SEC-22 and the putative RNA binding protein C12D8.1. In two additional Y2H screens, we found that SID-5 interacts with multiple syntaxin SNAREs, including SYX-6, whereas SEC-22 only interacts with SYX-6. SNAREs usually function in vesicle fusion processes. We found the two SNARE proteins SEC-22 and SYX-6 to be negative regulators of RNAi and to localize to late endosomes/MVBs. In addition, loss of sid-5 leads to an endosome maturation defect. Finally, we found that the putative RNA binding protein C12D8.1 negatively regulates RNAi inheritance and that C12D8.1 mutant animals show impaired RNAi upon targeting a new gene. Taken together, the results presented in this thesis provide us with more evidence for the connection of the membrane transport system and RNAi. The identification of a putative negative regulator of RNAi inheritance further enriches this research field.