The mosquito Aedes aegypti is responsible for 50 million dengue fever infections in humans each year. A novel control strategy, named RIDL (Release of Insects carrying a Dominant Lethal) relies on releasing large numbers of genetically sterile male insects in order to control pest populations. This thesis describes the development of new tools to improve the efficiency of RIDL against Ae. aegypti and assessment of candidate strains for field release. <strong>Chapter 3</strong> describes a new selection system for Ae. aegypti based on ethanol susceptibility conferred by the alcohol dehydrogenase gene (Adh) from Drosophila melanogaster. I observed that the susceptibility of Ae. aegypti larvae to ethanol can be triggered by expression of Adh in larvae. <strong>Chapters 4</strong> and <strong>5</strong> focus on RIDL strains with a genetic sexing mechanism, for easy and stringent selection for males before mass-releases, eliminating disease- transmitting females. In <strong>Chapter 4</strong>, I describe the creation of a late-acting sexing strain of Ae. aegypti based on the Ae. aegypti doublesex (Aedsx) alternative splicing system. In <strong>Chapter 5</strong>, I describe an attempt to create an early-acting sexing system. Killing the females of the release generation early would free space and resources for the production of males. This was done by combining the Adh gene and the Aedsx alternative splicing system described in <strong>Chapters 3</strong> and <strong>4</strong>. <strong>Chapter 6</strong> reports the results of a comparison, in terms of quality and productivity, between an existing Ae. aegypti RIDL strain and a wild-type control. Results showed equivalent female quality and productivity between the two strains, while RIDL males were less fertile in comparison with wild-type males. RIDL eggs also seemed more susceptible to long- term storage. The results of this work show promise for development of novel RIDL strains that may be used in the field to control disease-transmitting mosquitoes.

Made available in DSpace on 2016-04-27T18:15:45Z (GMT). No. of bitstreams: 1 Edson Cinaqui Filho.pdf: 2131297 bytes, checksum: aef7f7cc013ddbf281ee30bc79baa5a2 (MD5) Previous issue date: 2015-03-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Transgenic organisms have inserted into its genome one or more DNA sequences of a species of interest, to ensure the inserted genic expression. Of these genes. These sequences (genes) may come from any living organismo (bactéria, fungus, plants, animals, protozoan) or nonliving (vírus). The permission for planting and commercialization of these organisms which are modified to resist various environmental pressusres raised the debate about its biosafety to the environment and to human and animal health. In this research were analyzed and discussed the decision-making processes involved in the approval of three varieties of transgenic corn in Brazil: the Liberty Link herbicide tolerant, insect resistant MON810 and Bt11 also resistant to insects. The choice of analyzing corn soybeans, is due the fact that Brazil is one of the centers of diversity of this plant and also for its importance to indigenous tribes and traditional communities. The studies submitted by the companies planning release the transgenic seeds were inadequate perfomed at short notice and grounded in statistical methods poorly documented. The samples were not representative and the number of repetitions insuficiente. Studies on the possible effects of there transgenic varieties on populations of non-target organisms were performed improperly, disregarding its ecological importante. The releases of these three varieties of transgenic com in Brazil contradicted Article 225 of the Federal Constitution which states that everyone has the right to a balanced environment which is essential to a healthy quality of life, and the Government should protect and preserve it for presente and future generations.The permission for planting and sala of transgenics occurred throught a comission in which the majority of members were interested in a transgenic research funded by multinationals. In addition to the political nature of problems, the release of transgenic corn wounded three basic environmental principles: precaution, sustainability and responsibility, for damage. Currently several studies attest problems in human and animal health and in the environment arising from transgenic organisms. Thus, the adoption of the Precautionary Principle should be essential before the release of transgenic corn in Brazil, to ensure that with so many scientific uncertainties the environment small farmers and the health human beings and other animals would be sabe. , to ensure that with so many scientific uncertainties, the environment, small farmers and the health of human beings and other animals would be safe / Organismos transgênicos possuem inseridos em seu genoma uma ou mais sequências de DNA de uma espécie de interesse, de modo a garantir a expressão gênica destes genes inseridos. Essas sequências (genes) podem provir de qualquer organismo vivo (bactérias, fungos, plantas, animais, protozoários) ou não vivo (vírus). A liberação para plantio e comercialização destes organismos modificados e resistentes a diversas pressões ambientais levantaram o debate sobre a biossegurança destes ao meio ambiente, saúde humana e animal. Neste trabalho foram analisados e discutidos os processos decisórios envolvidos na aprovação de três variedades de milhos transgênicos no Brasil: o Liberty Link tolerante a herbicida, o MON810 resistente a insetos e o Bt11 também resistente a insetos. A escolha de analisar o milho e não a soja, se deve ao fato do Brasil ser um dos centros de diversidade dessa planta, e também por sua importância para os povos indígenas e para as comunidades tradicionais. Os estudos apresentados pelas empresas que pleiteavam liberar suas sementes transgênicas foram inadequados, realizados à curto prazo e embasados em métodos estatísticos mal documentados. As amostragens não foram representativas e os números de repetições insuficientes. Estudos sobre os possíveis efeitos destas variedades transgênicas em populações de organismos não-alvo foram realizados de forma inadequada, desprezando a importância ecológica destes. As liberações destas três variedades de milho transgênico no Brasil contrariaram o Artigo 225 da Constituição Federal que afirma que todos têm direito ao meio ambiente em equilíbrio e essencial à sadia qualidade de vida, e que caberia ao Poder Público defende-lo e preservá-lo para as gerações presentes e futuras. As liberações para plantio e comercialização de transgênicos ocorreram por meio de uma comissão cuja maioria dos membros estavam interessados em pesquisas de transgenia com financiamento de multinacionais. Além dos problemas de cunho político, a liberação do milho transgênico feriu três princípios ambientais básicos: da precaução, da sustentabilidade e da responsabilidade por danos. Atualmente diversos estudos atestam problemas na saúde humana, animal e ao meio ambiente decorrentes de organismos transgênicos. Desta forma, a adoção do Princípio da Precaução se fazia fundamental antes da liberação do milho transgênico no Brasil, para garantir que diante de tantas incertezas científicas o meio ambiente, o pequeno agricultor e a saúde do ser humano e demais animais estariam seguros

The Anterior Gradient 2 (AGR2) protein has been implicated in a variety of biological systems linked to cancer and metastasis, tamoxifen-induced drug resistance, pro-inflammatory diseases like IBD and asthma, and limb regeneration. The molecular mechanisms by which AGR2 mediates these various phenotypes in disease progression in both cancer and IBD are poorly understood, as is the biological function(s) of AGR2 under non-disease conditions. Here, we use a combination of biochemical techniques, organ culture, cell biology and mouse genetics to investigate the biological significance of AGR2 both in cell lines and in vivo. We present data based on phage-peptide inter-actomics screens suggesting a role for AGR2 in mediating the maturation and trafficking of a class of membrane and secretory proteins, and investigate a putative interaction between AGR2 and one member of this class of proteins. We also describe the construction of a universal vector for use in making a variety of transgenic animals, and then present data showing its use as a promoter reporter, and attempt to investigate the temporal and spatial expression of AGR2 in the developing and adult mouse. Further, we present data describing the localisation pattern of AGR2 in the developing murine kidney using a combination of organ culture and antibody staining, and suggest a role for AGR2 in the developing kidney based on this data that is in agreement with a chaperone function for membrane and secretory proteins. Together, these data suggest that AGR2 has an intrinsic consensus docking site for a subset of its client proteins, that AGR2 plays a role in protein maturation in ciliated cell types, and provides a novel biological model to dissect the role of AGR2 in ER-trafficking.

Made available in DSpace on 2016-04-28T20:12:51Z (GMT). No. of bitstreams: 1 2005- Camila Moreno.pdf: 773163 bytes, checksum: a0f615c8421820319c67af6265ee6496 (MD5) Previous issue date: 2005-12-08 / This work seeks to relate the ressurgence and protagonism of the peasant movements on the space of world articulation and alternatives building to neoliberalism, identified with the World Social Forum (WSF) process. On the peasants discourse to globalization in this context, the opposition to the genetically modified organisms (transgenics) in its introduction in agriculture has served as a catalytic element and mobilized other movements and segments of civil society, beyond the farms and rural areas. Such effect is due to the political characterization in framing the introduction of this technology; this has been obtained exceedingly by the peasant s discourse on defense of its territories and the Food Sovereignty of peoples and States, facing the control of the global agro-food systems by some few transnational corporations of the sector, as in the emblematic case of transgenic soy, the Monsanto company. Located within the macro debate on agriculture liberalization in the World Trade Organization (WTO); the juridical international framework to protect intellectual property; and the risks of genetic contamination of ecosystems, the opposition to transgenics in agriculture offers a red thread to comprehend the dynamics of how capitalism operates today. In the process through peasants became proletarians, the genetic control and privatization of the seeds serve as a corner stone. In this sense, transgenics update and give new meaning to the nucleus of themes and problems known for the marxist tradition as the Agrarian Question. Also, the peasant movements restate to theoretical framing the centrality of the labor process in apprehending the contradictions in reality, highlighting the ecological dimensions, and qualifying the productive activity that directly transforms nature; from there it is associated a critic to the ideology of technological progress as if dissociated of a political project. These imbrications are specially suitable to recover Marx today, freed from Marxism, seeking to update the critical perspective of political economy in relation to the contemporary concept of environmental rationality, thus incorporating the ecological dimension to politics as to economy. In this view, the peasant movements would be on the avant-garde of contesting the capitalist structures of production, as would they be pointing to on the interface of politics and ecology the ways to build a socialist project for the XXI century. / Este trabalho trata de relacionar a emerg?ncia e o protagonismo dos movimentos camponeses no espa?o de articula??o mundial de constru??o de alternativas ao neoliberalismo, identificado no processo do F?rum Social Mundial (FSM). No discurso ? globaliza??o dos camponeses nesse contexto, o tema da oposi??o aos organismos geneticamente modificados (transg?nicos) em sua introdu??o na agricultura tem servido de elemento catalisador e mobilizado outros movimentos e grupos da sociedade civil, para al?m do campo e do rural. Este efeito deve-se ? caracteriza??o pol?tica da introdu??o dessa tecnologia, lograda sobremaneira no discurso campon?s em defesa dos territ?rios e da soberania alimentar dos povos e dos Estados nacionais frente ao controle do sistema agroalimentar mundial por algumas empresas transnacionais do setor, como no caso emblem?tico da soja transg?nica, a Monsanto. Inserida no debate macro das negocia??es agr?colas no ?mbito da Organiza??o Mundial do Com?rcio (OMC), do marco jur?dico internacional de prote??o da propriedade intelectual e dos riscos ambientais da contamina??o gen?tica dos ecossistemas, a oposi??o aos transg?nicos na agricultura oferece um fio condutor para compreender a din?mica de funcionamento do capitalismo hoje, onde a proletariza??o dos camponeses, com o controle gen?tico e a privatiza??o das sementes, serve de pedra de toque. Dessa forma, os transg?nicos atualizam e ressignificam o n?cleo de temas e problemas que ficou conhecido na tradi??o marxista como a Quest?o Agr?ria. Ainda, os movimentos camponeses reafirmam para a problematiza??o te?rica a centralidade do trabalho na apreens?o das contradi??es da realidade, ressaltando a dimens?o ecol?gica, na qualifica??o do processo produtivo que diretamente transforma a natureza, incluindo desde a? a cr?tica ? ideologia do progresso tecnol?gico como dissociado de um projeto pol?tico. Esta imbrica??o ? especialmente oportuna para recuperar Marx hoje, depurado do marxismo, buscando atualizar a perspectiva cr?tica da economia pol?tica em rela??o ao conceito contempor?neo de racionalidade ambiental, incorporando a dimens?o da ecologia ? pol?tica tanto como ? economia. Nessa leitura, os movimentos camponeses estariam na vanguarda da contesta??o ?s estruturas de produ??o capitalistas hoje, bem como apontariam, na indissociabilidade entre ecologia e pol?tica, os rumos de constru??o de um projeto socialista para o s?culo XXI.

One of the challenges in the 21st Century is to overcome the recalcitrance of lignocellulose for the production of liquid biofuels. Lignin is one of the key factors in this recalcitrance. Grasses such as Miscanthus and switchgrass could become major sources of lignocellulose. Barley has potential as a genetically-tractable research model for such novel bioenergy crops and also as a bioenergy crop itself. This thesis concerns the 4CL and the CCR enzymes on the lignin pathway which were chosen as the targets to manipulate lignin in barley. They were selected because there is evidence that suppression of each of them in dicot species can lead to increased saccharification. The 4CL and CCR genes constitute multigene families where members have different expression patterns. RNAi was used to down-regulate 4CL1 and CCR1 using a constitutive promoter via Agrobacterium-mediated transformation of barley. From an extensive screen of the primary transformants for changes in protein level and lignin content, six CCR and four 4CL lines were taken forward for detailed analysis. Antibodies were also raised against barley 4CL and CCR recombinant proteins and these showed substantial reductions in the respective target protein levels in the RNAi lines. Both 4CL and CCR transgenic lines had significant reductions in lignin content, and CCR lines had changes in lignin structure due to changes in the proportions of acid soluble and acid insoluble lignin. No substantial consistent adverse effects on key agronomic traits were apparent in the 4CL and CCR transgenics. Selected 4CL and CCR transgenics had improved saccharification yield after using three different pretreatment methods, which is a desirable feature for biofuel production.

Made available in DSpace on 2014-12-17T15:18:09Z (GMT). No. of bitstreams: 1 JairMS.pdf: 604378 bytes, checksum: 8f3220e89d5c178954aadb5186b98f52 (MD5) Previous issue date: 2009-02-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Hybrids among transgenic plants and related species are expected to occur if they are sympatric and when there are not crossing barriers; as is the case, in Brazil, of cry1Ac transgenic cotton and Gossypium barbadense. This species has been maintained as dooryard plants, and should be preserved as a genetic resource. Hybrids were evaluated about traits related to fitness, leading to infer about its chances of survivor and selection. A barbadense genotype collected at the state of Mato Grosso was outcrossed to the variety DP 404, containing the gene cry1Ac, and to the isoline DP 404. All the F1 individuals and 122 among 170 F2 individuals expressed the toxin, and presented levels of resistance to pink bollworm (Pectinophora gossypiella) and cotton leafworm (Alabama argillacea) equivalent to the transgenic parent and superior to the isoline, barbadense or non transgenic hybrids. The percentage of germination and number of days to germinate did not differ among genotypes. Anthesis of the first flower and opening of the first cotton boll occurred earlier for herbaceous cotton and F1 hybrids than F2 population in average; all the populations presented a number of days to flower and opening of the first boll smaller then barbadense. The highest plants were barbadenses, and herbaceus the smallest, with F1 and F2 populations presenting intermediary heights. The number of seeds per plants were superior for F1 hybrids an herbaceous cotton, F2 populations were in average intermediary; the barbadense genotype produced the smallest number of seeds per plant. Pink bollworm, mainly, and also cotton leafworm, are important barbadense pests, so the transgene positive effect could favor the selection of hybrids, and hence G. hirsutum genome, against the maintenance of pure G. barbadense genome. The selection may be influenced by the plant uses: the smaller size of hybrids when compared to the barbadense may lead them to be differentiated from these parents to which medicinal properties are attributed; on the other hand, the greater boll production may favor hybrids maintenance with the purpose of producing lamp wicks, or use as an ornamental or swab / Espera-se que hibrida??es entre plantas transg?nicas e esp?cies pr?ximas ocorram sempre que haja simpatria e n?o existam barreiras de cruzamento, como ? o caso, no Brasil, do algodoeiro contendo o gene cry1Ac e a esp?cie Gossypium barbadense. Os barbadenses v?m sendo mantidos em quintais, e ? importante sua preserva??o como recurso gen?tico. H?bridos foram avaliados para caracteres relacionados com a adaptabilidade, inferindo sobre suas chances de sobreviv?ncia e sele??o. Para isto, obtiveram-se plantas F1 e F2 do cruzamento entre um algodoeiro barbadense coletado no estado de Mato Grosso com as cultivares DP404, contendo cry1Ac, e de sua isolinha DP4049. Todos os 37 indiv?duos F1 e 122 dentre 170 indiv?duos F2 avaliados expressaram cry1Ac, e apresentaram n?veis de resist?ncia ?s lagartas rosada (Pectinophora gossypiella) e curuquer?-doalgodoeiro (Alabama argillacea) equivalentes ao parental transg?nicos e superiores a isolinha, barbadense e h?bridos que n?o continham o transgene. N?o foram observadas diferen?as significativas para a porcentagem de germina??o ou quantidade de dias para germina??o. O florescimento e abertura do primeiro capulho ocorreram mais cedo nos algodoeiros herb?ceos e nos h?bridos que nas popula??es F2 em m?dia; todas as popula??es apresentaram um n?mero de dias para o florescimento e abertura do primeiro capulho significativamente mais baixo que os barbadenses. As plantas mais altas na matura??o eram os barbadenses, e os herb?ceos as mais baixas, sendo as popula??es F1 e F2 intermedi?rias. O n?mero de sementes por planta foi superior nos h?bridos F1 e algodoeiros herb?ceos, sendo as popula??es F2 intermedi?rias em m?dia, e os barbadenses aqueles que produziram menor n?mero de sementes. A lagarta rosada, principalmente, e tamb?m a curuquer?-do-algodoeiro s?o importantes pragas de G. barbadense, portanto o efeito positivo do transgene pode favorecer a sele??o de h?bridos contendo o transgene, e deste modo favorecer plantas que cont?m genoma de G. hirsutum, em detrimento da pureza do genoma de barbadense. A sele??o deve ser influenciada pelos usos da planta: o fato de os h?bridos serem mais baixos pode diferenci?-los dos pais barbadenses aos quais a propriedades medicinais s?o atribuidas; por outro lado, a produ??o bem maior de capulhos pode favorecer a manuten??o dos h?bridos quando se visa confec??o de pavios ou ornamenta??o de quintais e jardins

Transgenic seeds: A bioethics debate?The aim of this paper is to analyze, from a bioethical perspective, the social, cultural, environmental and moral impacts of the use of biotechnology for breeding transgenic crops. We place greater emphasis with regard to the use of transgenic seeds in agriculture, and their advantages and disadvantages compared to traditional crops. Transgenic crops are genetically modified organisms (GMO). There have been two antagonistic views about transgenic crops only due to its definition. We address the issue of transgenic seeds presenting these two views, and make a bioethical analysis that allows us to make a synthesis that may set what could be the most appropriate standing on this issue in light of bioethical principles. / El propósito del presente artículo es analizar, desde una perspectiva bioética, el impacto social, cultural, ambiental y moral del uso de la biotecnología moderna en el mejoramiento transgénico de los cultivos. Pondremos mayor énfasis en lo referente al uso de semillas transgénicas en la agricultura y sus ventajas o desventajas frente a los cultivos llamados tradicionales. Los transgénicos son organismos vivos genéticamente modificados (OGM). Solo con la definición de lo que es un transgénico, han aparecido dos corrientes antagónicas acerca de qué es y, qué no es lo correcto. Abordaremos el tema de las semillas transgénicas, presentando estas dos opiniones, para posteriormente hacer un análisis bioético que nos permitirá hacer una síntesis con la cual estableceremos qué es lo más adecuado respecto de este tema a la luz de los principios bioéticos

Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-12-29T16:49:58Z No. of bitstreams: 2 Tese - Rafael Choze - 2011.pdf: 2895418 bytes, checksum: 6942b3a804e34024bb7cd13f100e5663 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2014-12-29T16:50:59Z (GMT) No. of bitstreams: 2 Tese - Rafael Choze - 2011.pdf: 2895418 bytes, checksum: 6942b3a804e34024bb7cd13f100e5663 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-12-29T16:50:59Z (GMT). No. of bitstreams: 2 Tese - Rafael Choze - 2011.pdf: 2895418 bytes, checksum: 6942b3a804e34024bb7cd13f100e5663 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2011-04-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work, a new methodology which allows differentiating conventional and transgenic common beans, grown in greenhouse or under field conditions, based on modifications in chemical composition using 1H HRMAS NMR and infrared is proposed. Through NMR it was possible to identify differences in chemical composition between the beans, according to transgenic or conventional source, especially in aromatic hydrogen region. The 1H, gHSQC and gHMBC experiments conducted to the flavonoids quercetin and myricetin structures, present in higher contents in genetically modified cultivars. Moreover, through 1H HR-MAS NMR was also possible to identify, in mixture, the aminoacids threonine, valine, isoleucine, and lysine, and the oligosaccharides stachyose, raffinose, and verbascose. The NMR spectra of Pérola 5.1 and BRS Pontal 5.1, to which the transgene was received from Olathe 5.1, using crosses and backcrosses, showed the same signal pattern observed in Olathe 5.1 bean. This study also demonstrated that the influence of typical variables from field planting conditions had no significant influence on the ability of separation between cultivars transgenic and conventional. This methodology was corroborated by multivariate data analysis of the 1H NMR spectra. On the other hand, the infrared studies showed less conclusive results. The study of the influence of exposure to air indicated a decrease in the flavonoid myricetin content. For quercetin no change was observed. This study also points out the simplicity of using the HR-MAS NMR technique for food analyses. The measurement is highly simplified because it does not require any pretreatment of the sample apart from the addition of a small amount of D2O necessary to produce homogeneous dough and a field frequency lock. Moreover, due to the high concentration of the sample, measurement time in HR-MAS NMR is very short. / Neste trabalho, propõe-se uma metodologia que permita diferenciar feijões convencionais e transgênicos, cultivados em casa de vegetaçao sob condições controladas ou em campo, baseados em modificações na composição química, utilizando RMN 1H HR-MAS e infravermelho. Através da RMN foi possível identificar diferenças na composição química entre os feijões, segundo sua origem convencional ou transgênica, especialmente na região de hidrogênios aromáticos. Os espectros de 1H HR-MAS, gHSQC e gHMBC conduziram às estruturas dos flavonóides quercetina e miricetina, presentes em maior concentração no feijão geneticamente modificado. Além disso, através da técnica de HR-MAS, foi possível caracterizar os aminoácidos treonina, alanina, valina, isoleucina e lisina e os oligossacarídeos estaquiose, verbascose e rafinose, em mistura. As linhagens BRS Pontal 5.1 e Pérola 5.1, derivadas de cultivares de grande aceitação comercial, BRS Pontal e Pérola, e que receberam o transgene do feijão Olathe 5.1, através de cruzamentos e retrocruzamentos, apresentaram o mesmo perfil de variação química observado para as cultivares Olathe Pinto e Olathe 5.1. Esse estudo demonstrou ainda, que as variáveis edafoclimáticas, típicas de condições de plantio no campo, não tiveram influência significativa sobre a capacidade de separação entre cultivares transgênicos e convencionais. Esta metodologia foi corroborada pela análise multivariada dos dados dos espectros de RMN de 1H. Por outro lado, estudos realizados através da técnica de infravermelho demonstraram que os resultados foram menos conclusivos, quando comparados àqueles obtidos através de RMN. O estudo da influencia da exposição da cultivar ao ar, indicou uma variação no teor do flavonóide miricetina, visualizado pelo decréscimo da intensidade de seus sinais no espectro. Para o flavonóide quercetina, nenhuma variação foi observada. Por fim, esse trabalho aponta para a simplicidade do uso da técnica HR-MAS para análises de alimentos. A medida é extremamente simplificada, pois não requer nenhum prétratamento da amostra além da moagem e adição de gotas de D2O.

Although the “genome as a blueprint” metaphor has been pervasive in biology, recent advances in molecular biology have revealed a complex network of regulatory machinery that dynamically regulated molecular processes in response to environmental conditions. However, these patterns, as well as the evolutionary processes that underlie them, remain understudied in natural conditions. In 2010, the Deepwater Horizon oil spill released an estimated 4.9 million barrels of oil into the Gulf of Mexico, making landfall on salt marsh habitat dominated by the foundation species Spartina alterniflora. Despite the severe impacts to phenotype and fitness, S. alterniflora proved remarkably resilient in the face of the crude oil stress. Despite the tragedy of the Deepwater Horizon oil spill, the event represented a unique opportunity to explore the molecular mechanisms of oil tolerance in this highly resilient species. To understand how organisms regulate gene expression in natural settings and to identify best practices in genome-wide expression studies, we first surveyed a ten-year span of transcriptome-wide gene expression studies. We then confirmed the hypothesis that crude oil exposure would induce differential gene expression in affected populations, and whole-transcriptome microarray identified 3,622 genes that responded exclusively to oil stress. To confirm the function of candidate genes involved in resilience to oil stress, we used a highly-differentially expressed subset of these genes to construct gene interaction networks and identify target genes. We obtained T-DNA insertion genotypes of the emerging model grass species Brachypodium distachyon that were disrupted in these target genes for functional confirmation, but were unable to detect significant modulation of oil response through these heterologous knockouts. Finally, we isolated the phenotypic effects of crude oil exposure through greenhouse trials and found evidence that crude oil may have acted as a selective pressure, rather than an inducer of plasticity. Together, these studies identify novel patterns of gene expression in response to a severe but unpredictable stressor that has widespread impacts on a foundational salt marsh grass species. In addition, this dissertation represents a pathway to understanding functional genomics in non-model systems without extensive genomic resources.

No description available.