Les recherches sur les ARN non codants et leurs rôles biologiques ont transformé la conception des propriétés des génomes et de la régulation de l'expression génétique. Ces recherches sont ici analysées dans une perspective historique et philosophique. Elles permettent de caractériser certaines transformations théoriques, conceptuelles et méthodologiques affectant la biologie moléculaire contemporaine. La diversité des démarches d'investigation employées dans les travaux sur les ARN non codants est soulignée. Parmi ces démarches, les expériences exploratoires occupent une place importante, et sont à l'origine de bouleversements conceptuels et théoriques majeurs. L'affirmation selon laquelle la découverte des ARN non codants constitue une révolution scientifique est nuancée, et les apports de cette découverte sont caractérisés dans toute leur diversité. Les limites rencontrées par le concept de gène dans la biologie post-génomique sont précisées, et reliées à l'histoire de ce concept. Un statut possible pour le gène est alors proposé ; il reconnaît la diversité des éléments génétiques fonctionnels, la dimension historique des génomes, et les différents niveaux d'étude de la relation entre génotype et phénotype. Les recherches sur les ARN non codants affaiblissent par ailleurs la pertinence théorique du discours informationnel pour décrire la diversité des fonctions assurées par les acides nucléiques. Enfin, ce travail montre que les explications du rôle régulateur des ARN mettent en jeu différents types explicatifs, dépassant le cadre mécaniste. Un pluralisme explicatif est défendu, et le statut du concept de mécanisme dans la biologie moléculaire contemporaine est clarifié. / Research on non-coding RNAs and their biological roles has transformed the way biologists conceptualize genomic properties and the regulation of genetic expression. This work analyzes this research from both a historical and philosophical perspective. It helps characterize some theoretical, conceptual and methodological transformation currently affecting moleculau biology. I stress that multiple modes of investigation are employed in research on non coding RNAs. Particularly important among them is exploratory experimentation, which brings about major conceptual and theoretical changes. I temper the claim that the discovery of non-coding RNAs has triggered a scientific revolution and characterize the multifaceted contributions of this discovery. I identify some limits faced by the gene concept in post-genomic biology, and relate them to the history of this concept. I suggest a possible status for the gene, which to study the relation between genotype and phenotype. Besides, research on non-coding RNAs leads to question the theoretical relevance of informational concepts to describe the diverse functions fulfilled by nucleic acids. Finally, I show that explanations of the regulatory roles of RNAs involve different explanatory schemes, which do not fit the mechanistic framework. I advocate an explanatory pluralism, and clarify the status of the concept of mechanism in contemporary molecular biology.

In this dissertation, I examine how biological data practices enable researchers to interact with and enact biological life in statistical ways, and how this poses challenges to the use and integration of biological knowledge with clinical practices. Instead of considering data as a pre-existing cognitive representation of the world, I combine scholarship on the anthropology of science with scholarship from science and technology studies to consider data as a form of material practice. I consider, in other words, how data is intertwined with technologies, people, and values, such that data is used to make normative and naturalized claims about biology and disease. To explore the generation, interpretation, and use of biological data, I focus on the field of “metabonomics”—the post-genomic study of metabolism—as it is carried out within the Biomolecular Medicine Laboratory (BMM) at Imperial College London. In doing so, I examine how metabonomics researchers use biochemical techniques and multivariate statistics to investigate metabolism and disease. After providing an overview of the literature, central questions, and methodology that frame this dissertation, I examine how multivariate statistical practices are central to the historical identity and epistemic culture of metabonomics research at the BMM. From there, I demonstrate how multivariate statistics require and enable metabonomics to enact metabolism as an inherently complex entity. Consequently, I examine how researchers struggle to assign the categories of “normal” and “abnormal” to dynamic notions of metabolism and health. I then explore how the translation of metabonomics knowledge into clinical practices places value on multivariate forms and large volumes of information, eclipsing the importance of human interpretation and judgment. Finally, I examine how metabonomics research is used to develop personalized medicine, but in ways that make it difficult to address the health of individual patients.

This thesis examines how the first 10 seasons of CSI: Crime Scene Investigation (CBS, 2000–) engage with discourses on science. Investigating CSI’s representation of scientific practices and knowledge, it explicitly attempts to look beyond the generic assumption that forensic crime dramas simply ‘celebrate’ science. The material is analysed at three different levels, studying CSI’s wider cultural discursive context, genre linkages, and audio-visual form. In order to fully account for the series’ specificity, the thesis undertakes comparative analyses of earlier forensic crime dramas and other relevant audio-visual material. Close textual readings of certain thematic tropes, narrative devices and visual imagery in CSI are thus supplemented by historical studies of their extended generic backgrounds. This textual-historical approach generates a general argument that CSI dramatizes and evokes a number of different, and often contradictory, scientific ideas, perspectives and discursive shifts. The thesis concludes that CSI stages a transnational cultural forum, simultaneously engaging with residual, dominant and emergent discourses on science.  Throughout, close attention is paid to the multiple perspectives and viewpoints that allow the series to appeal to a wide and heterogeneous global audience. Furthermore, the thesis asserts that CSI specifically articulates a post-genomic structure of feeling, which begins to express the wider cultural implications of an emergent discursive shift whereby the instrumentalisation of molecular science seemingly offers more possibilities for human intervention into biological processes. Thus, the study demonstrates how CSI’s discourse on science treats recent scientific developments as engendering a cultural process of redefinition, questioning foundational concepts such as truth, identity, body, kinship and emotions.

Made available in DSpace on 2014-08-20T13:32:58Z (GMT). No. of bitstreams: 1 dissertacao_carla_silveira.pdf: 1301704 bytes, checksum: e35505f057e1acb40d6e79b4da74308d (MD5) Previous issue date: 2011-05-26 / Oats (Avena sativa L.) are a winter cereal used for both humans and livestock, giving a great importance on the world stage. In the post-genomic era new sequenced genomes can be used to derive functions of organisms from the knowledge of these systems. In this work were apply this approach to the analysis of gene family of aquaporins in oats. The aquaporins are major intrinsic proteins (MIP) that have been characterized as facilitating the water flow. They are also known as water channels, glycerol facilitators and aquaglyceroporins, recent data suggest that they facilitate the movement of other molecular low weight metabolites. The presence of these genes is importance for the development and adaptation of plants, however, until now there are not studies reporting the identification of aquaporins in the oat genome. In this report we identified two sequences identified as potential aquaporins present in the genome of oat. Considering the number of aquaporin genes present in genome of rice, Arabidopsis, maize and wheat and the complexity of its polyploid genome, it is estimated that oats may have around 20 or more copies of these genes in each genome. Given the growing problems of flooding and drought, the need for cultivation in areas affected by salinity and the proven role of MIPs on plant response to stresses related to water availability, the investigations of these genes are essential in oats too. However a greater number of these genes can be identified in the future, this study was an important step in its characterization. / A aveia (Avena sativa L.) é um cereal de inverno utilizado tanto para a alimentação humana quanto animal, apresentando uma grande importância no cenário mundial. Na era pós-genômica novos genomas sequenciados podem ser utilizados para inferir funções de organismos a partir do conhecimento de outros sistemas. Neste trabalho foi aplicada essa abordagem à análise de genes da familia das aquaporinas em aveia. As aquaporinas são proteínas intrínsecas de membrana (MIP) que têm sido caracterizadas como facilitadoras do fluxo de água. São também conhecidas como canais de água, glicerol facilitadores e aquagliceroporinas. Dados recentes sugerem que elas facilitam a circulação de outros metabólitos de baixo peso molecular. A presença dos genes que codificam essas proteínas é de suma importância para o desenvolvimento e adaptação das plantas, contudo, até hoje não existiam estudos relatando a identificação de genes de aquaporinas no genoma da aveia. O sequenciamento e caracterização in silico das sequências obtidas neste trabalho propõem a presença de genes que codificam prováveis aquaporinas. Foram identificadas duas sequências como prováveis aquaporinas presentes no genoma da aveia. Considerando o número de genes de aquaporinas presentes no genoma do arroz, Arabidopsis, milho e trigo e a complexidade de seu genoma poliplóide, estimase que a aveia possua mais cópias desses genes. Tendo em vista os crescentes problemas de alagamento e/ou seca, a necessidade de cultivo em áreas afetadas pela salinidade, e o comprovado papel das MIPs na resposta das plantas a estresses relacionados com a disponibilidade de água, as investigações desses genes em aveia são essenciais. Contudo um número maior desses genes poderão ser identificados e caracterizados, esse estudo representa uma etapa importante para sua caracterização.