Thesis advisor: Eric S. Folker / Skeletal muscle is a syncytial cell type in which the multiple nuclei are evenly spaced along the cell periphery. During muscle development, the myonuclei undergo an elaborate set of movements to achieve this precise positioning throughout the muscle. The importance of proper nuclear positioning is highlighted by the correlation between mispositioned nuclei and muscle disease. However, the mechanisms that govern this energetically expensive process as well as the influence nuclear positioning has on muscle cell function remains to be elucidated. The goal of this thesis is to determine the molecular factors and subsequent mechanisms that regulate nuclear movement and how such pathways are disrupted in various muscle diseases. Since many of the key cellular features are conserved between Drosophila and mammalian muscles, we utilize Drosophila musculature as a model system to study myonuclear positioning during muscle development. In this thesis, we provide the first evidence that nuclei experience attractive and repulsive interactions with one another as they actively migrate. Furthermore, we demonstrate that these nucleus-nucleus interactions are critical for proper nuclear positioning, and that they are distinctly regulated by genes that are associated with two different muscle diseases, Emery-Dreifuss muscular dystrophy and Centronuclear myopathy (Chapter 2). We then elaborate upon the genetic mechanisms through which CNM-linked genes regulate nuclear positioning (Chapter 3). Finally, we show that proper nuclear movement requires both the separation of nuclei from their neighbors as well as the transmission of force, that is generated from the cytoskeleton, to move nuclei within the cell (Chapter 4). Together, the work presented in this thesis provides new perspective and mechanistic insights into the genetic factors and physical forces that regulate nuclear movement during muscle development and how such pathways are disrupted in disease, while emphasizing the importance of studying such dynamic processes within an in vivo system. / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

The establishment of cell polarity is a vital requirement for cellular processes such as proper cell division, growth and movement. Cell polarization relies on different internal and external cues in order to reorient the cell growth machinery along the axis of polarity. The core mechanisms involved in establishment of polarized growth are highly conserved from yeast to humans. Cells of the fission yeast Schizosaccharomyces pombe grow in a highly polarized fashion, with cell growth restricted to the cell tips, making fission yeast an excellent model system to study polarized growth. Here I describe a system for long-term live-cell imaging of fission yeast polarized growth that is stress free, physiological and accessible to media change and drug addition. I use this improved imaging system along with yeast genetics and drug perturbations to address how cell polarity is established and maintained in fission yeast. I have shown that fission yeast growth polarity depends on competition and cooperation among three distinct internal polarity cues: 1) A microtubule-based cue involving Tea1/Tea4 polarity proteins positively regulates polarized growth, initially at the “old” cell end (i.e., the end that pre-existed in the mother cell) and later at the “new” cell end (i.e. the end that is generated by septation), in order to initiate the transition from monopolar to bipolar growth (also known as New End Take-Off, or “NETO”). 2) An actin cable-based cue “clears” polarity proteins from the new end immediately after cytokinesis thereby reinforcing old-end growth. As a result perturbation of actin cable-based transport by either deleting actin cable nucleator For3 or cable-based transporter Myo52 results in premature bipolar growth. 3) A novel “memory-based” growth polarity cue helps to establish polarized growth in the absence of the microtubule-based cue. This memory-based cue is dependent on the predicted transmembrane proteins Rax1/Rax2. In the absence of both Tea1/Tea4 cue and Rax1/Rax2 cue, cells depend on septation cue and grow exclusively from the cell ends generated by septation. Furthermore, both Tea1/Tea4 and Rax1/Rax2 cue are important to maintain polarized growth under various environmental stresses. In fission yeast, during interphase, nucleus is positioned at the centre of the cell and this precise positioning of nucleus, which is important for defining the position of cytokinetic ring is thought to be exclusively MT-dependent. Here I show that MT-independent nuclear movement exists in fission yeast and this nuclear movement is mediated by actin cables and type myosin myo52. Furthermore, I show that actin cable might be important for buffering the pushing forces generated by MTs on the nucleus. In this way both microtubules and actin cables are involved in nuclear movement in fission yeast.

Les mouvements nucléaires sont importants pour une multitude de fonctions cellulaires et sont induits par des forces produites par des protéines moteurs et le cytosquelette. Lors de la formation et régénération de myofibres, les noyaux migrent du centre à la périphérie de la cellule pour son bon fonctionnement. De plus, certaines maladies musculaires sont caractérisées par une accumulation de noyaux centraux. En utilisant une approche théorique et empirique, nous démontrons que le mouvement de noyaux vers la périphérie des myofibres est induit par des forces centripètes autour des noyaux ainsi que par des changements locaux de rigidité nucléaire. Ces forces centripètes sont générées par la contraction de myofibrilles et par leur réticulation autour des noyaux. Les changements de rigidité nucléaire relèvent d’une asymétrie de la distribution de la lamin A/C. En débutant par BIN1, gène muté dans les myopathies centro-nucléés (CNM), nous avons identifié la cascade moléculaire à l’origine du mouvement des noyaux. Nous montrons que l’Amphiphysin 2 (BIN1) est indispensable pour le recrutement de N-WASP, activateur du complexe Arp2/3 afin de promouvoir la polymérisation de l’actine. Cette cascade est nécessaire au mouvement des noyaux vers la périphérie et pour la formation de triades transversales. Cet enchainement est perturbé chez certains patients portant des mutations de BIN1 car cela affecte la bonne localisation de l’Amphiphysin 2. Bien que provenant de la même cascade, le mouvement des noyaux vers la périphérie et la formation transversale de triades sont des processus indépendants. Un complexe de Arp2/3 contenant Arpc5L avec la γ-actine organisent la desmine et donc la réticulation des myofibrilles important pour le mouvement nucléaire. En revanche, un complexe de Arp2/3 contenant Arpc5 avec la β-actine est nécessaires à la formation de triades transversales. / Nuclear movements are important for multiple cellular functions and are driven by forces originating from motor proteins and cytoskeleton. During skeletal myofiber formation or regeneration, nuclei move from the center to the periphery of the myofiber for proper muscle function. Furthermore, centrally located nuclei are found in different muscle disorders. Using theoretical and experimental approaches, we demonstrate that nuclear movement to the periphery of myofibers is mediated by centripetal forces around the nucleus in combination with local changes of nuclear stiffness. The centripetal forces are generated by myofibril contraction, cross-linking and zipping around the nucleus. Local changes of nuclear stiffness are achieved by asymmetric distribution of lamin A/C. Beginning with BIN1, gene mutated in centronuclear myopathies (CNMs); we identified the molecular cascade involved in nuclear movement to the periphery. We show that Amphipysin 2 (BIN1) is important for N-WASP recruitment which itself activates the Arp2/3 complex to induce actin polymerization. This cascade is important for nuclear movement to the periphery and transversal triad formation. This pathway is perturbed in certain patients harboring BIN1 mutations as it leads to mis-localized amphiphysin 2. Despite originating from the same pathway, peripheral nuclear movement and transversal triad formation are independent processes. An Arp2/3 complex containing Arpc5L together with γ-actin organize desmin to cross-link and zip myofibrils for nuclear movement whereas an Arp2/3 complex containing Arpc5 together with β-actin is required for transversal triad formation.

Thesis advisor: Eric S. Folker / Thesis advisor: David R. Burgess / Skeletal muscle is a multinucleated cell type in which the many nuclei are precisely positioned to maximize the distance between adjacent nuclei. In order to reach this final positioning, nuclei undergo an elaborate set of movements during muscle development. The disruption of this process is evident throughout muscular dystrophies and myopathies. However, the contribution of aberrant nuclear positioning toward disease progression is unclear and the mechanisms regulating nuclear movement and positioning are poorly defined. The goal of this thesis is to determine the contribution of disease-linked genes to the regulation of nuclear movement and positioning and how these mechanisms are coordinated in skeletal muscle. In this thesis, we utilize Drosophila melanogaster skeletal muscle as an in vivo model system to investigate nuclear positioning throughout muscle development and correlate aberrant nuclear positioning with a decrease in muscle function. We provide the first evidence of distinct mechanisms that are independently regulated by genes that are associated with two different muscle diseases, Emery-Dreifuss muscular dystrophy and Centronuclear myopathy (Chapter 2). We also provide evidence that Emerin-dependent regulation of the LINC complex is a critical determinant of nuclear positioning and for the first time demonstrate a division of Emerin functions among the two Drosophila emerin homologs, bocksbeutel and otefin (Chapter 3). Finally, we conduct a proof-of-concept screen to identify novel regulators of muscle development and function (Chapter 4). Together, the work presented in this thesis provides a framework to further our understanding of the mechanisms regulating nuclear movement and positioning as well as muscle development as a whole. Using the tools and techniques developed throughout this thesis, we provide novel insight into the mechanisms regulating nuclear movement and positioning and strengthen Drosophila as an in vivo model for investigating muscle development and function. / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

本研究は、トルコで40年以上にわたり続く反原発運動の特徴や戦略を分析するとともに、環境運動がトルコの民主化過程において果たした役割を考察したものである。社会運動研究の枠組みを採用し、運動参加者の用いる表現など文化的側面にも注目して、運動のフレーミング戦略を分析した。反原発運動は自らを「自由と民主主義を求める運動」としてフレーミングし、運動スタイルの祝祭性や創造性を通じて、運動過程においても民主的空間を予示的政治として実現させていることを明らかにした。 / This study evaluates the role of environmental movements in Turkey’s democratization process, with a specific focus on anti-nuclear movement, which has continued since the middle of the 1970s. To analyze the anti-nuclear movement’s features and strategy, this study uses theories of social movement and flaming analysis, focusing on how the movement appeals to the public and expresses itself. This study found out that the anti-nuclear movement in Turkey flames itself as a movement for freedom and democracy. Besides, as prefigurative politics, the movement embodies freedom and democracy within the ongoing practice of the movement through its festival-like style and creativity. / 博士(グローバル社会研究) / Doctor of Philosophy in Global Society Studies / 同志社大学 / Doshisha University

La contestation antinucléaire au Rhin supérieur marqua le début des mouvements antinucléaires en France et en Allemagne. Tandis que le mouvement en Allemagne trouva bientôt un large soutien dans la société puis dans la sphère politique, le mouvement ne parvint pas à s’imposer en France. En outre, les origines du mouvement en Alsace sont presque tombées dans l’oubli. Ma thèse propose de retracer le développement du mouvement antinucléaire au Rhin supérieur. A partir d’une histoire croisée1, il s’agit d’analyser la coopération des groupes antinucléaires badois et alsaciens dans leur lutte contre l’industrialisation de la vallée du Rhin et contre la construction des centrales nucléaires le long du Rhin dans les années 1970 et 1980. Sur la base d'une analyse de la structure et des activités des initiatives des citoyens, elle examine la confrontation des militants antinucléaires avec les responsables politiques dans les deux pays, leur présence dans l’espace public, par exemple dans la presse régionale, les aspects culturels du mouvement antinucléaire ainsi que la création d'un espace public oppositionnel. Partant d’une analyse au niveau régional, j’aimais également faire des déductions sur l’évolution du mouvement antinucléaires au niveau national des deux pays. / Protests against nuclear power plants in the upper Rhine region in the early 1970s marked the beginning of the anti-nuclear movements in France and Western Germany. On both sides of the Rhine, citizens founded action groups to fight against the construction of nuclear power plants in Fessenheim and Wyhl and against the industrialization of the region in general. By using new forms of protest such as the peaceful occupation of construction sites, the activists had critical impact on the culture of civil protest and the evolution of the new social movements in France and especially in Western Germany. By way of a histoire croisée, this doctoral thesis takes a close look on how German and French citizens’ initiatives cooperated and which forms of protest they chose to draw the attention of the people and the governments to their cause. Various action groups from Baden and Alsace formed the “Badisch-Elsässischen Bürgerinitiativen, joining their forces to articulate their dissent towards decisions taken by the governments and the energy providers. Furthermore, the interaction and spill-over-effects between the anti-nuclear activists in the “Dreyeckland”, an imaginary region brought to life by German, French and Swiss anti-nuclear activists are examined. By stressing common cultural roots such as local dialect and the regional history, the anti-nuclear activists in the upper Rhine region tried to distinguish themselves from the authorities in Paris and Stuttgart. Finally, based on a regional study, it is analyzed which influence the citizens’ initiatives had on the anti-nuclear movements in Germany and France in general.

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Ausgehend von der Fragestellung, wie es möglich ist, dass der Körper durch bestimmte Erscheinungen und Handlungen zur Ressource visueller Kommunikation im Protest wird, leistet die vorliegende Dissertation zwei innovative Forschungsbeiträge: Zum einen wird die Rolle des Körpers in der Interaktionsordnung kollektiven Handelns theoretisch aufgearbeitet. Damit werden zwei miteinander verwobene Lücken im Bereich der Protest- und Bewegungsforschung adressiert: Die unzureichende Auseinandersetzung mit visuellen Aspekten der Aktivität sozialer Bewegungen und die, trotz einiger Aufmerksamkeit für soziale Inszenierung, weitgehende Ausblendung der Rolle des Körpers bei der Betrachtung von Bewegungshandeln. Zum anderen wird auf Grundlage der theoretischen Erkenntnisse eine Methodologie entwickelt, die sich besonders für die Erforschung von Körperlichkeit in Verbindung mit den Interaktionsdynamiken im Protest eignet. Den Körper operationalisiere ich als Visualisierungsmedium im Konzept des Bild-Körpers mit Anleihen bei der Bild- und Drama-Theorie. Die empirische Analyse von Videomaterial zu den Anti-Castor-Protesten in der Region Wendland (Deutschland) des Jahres 2008 zeigte, dass der Körper als Symbolträger in Mikrodramen - kurzen dramatischen Interaktionsfolgen - in Erscheinung tritt, über die der Protest selbst zum mobilisierenden Ereignis wird. Durch Mikrodramen werden die Akteure unmittelbar mit den Narrativen und Master-Frames des Protests verbunden. Der sonst rhetorische Konflikt zwischen Aktivisten und Protestadressaten wird physisch manifest in Zeit und Raum. Die Verkörperung normativ geladener Konstellationen von antagonistischen Charakteren ist dabei ein wesentliches Moment. Die notwendige Spannung wird durch die Kompositionen der Bild-Körper vor allem im Sinnbild der Grenzverletzung konstruiert, worin der Angriff und die Verteidigung des Körpers eine Verbindung zu den emotionalen Konstruktionen der Würde und des Anstands herstellen. / By asking how the human body becomes a crucial resource of visual communication in protest, this research advances scholarship in two main ways. First, I theorize the role of the body in terms of its appearances and actions, and in relation to collective action. Despite some scholarship attending to performative politics, this inquiry addresses several gaps in the theorizing about social movements such as the visual and embodied aspects of protest. Second, to anchor my theorization of the socially and physically situated body, I develop a methodology for researching corporality in association with protest interaction dynamics. I identify and conceptualize the body as a medium of visualization, which I call the pictorial body. Linking the pictorial body concept to the interface between scripts, narratives, and genres (SNG complex) lends the analyses to accounts of visual and dramaturgical theory. Empirically, I use original video data of the 2008 Anti-Castor protest campaign in Germany's Wendland. Findings show that the pictorial body is a primary carrier of symbolism in protest micro-dramas - short dramatic interaction episodes between challengers, targets, and third parties. As the most proximate medium, corporeal mobilizing experience - the call for action - can be treated as an outcome of protest action rather than only as a precondition. I argue that the embodied nature of micro-dramas during protest directly connects actors to movement narratives and master frames by making physically manifest in both space and time what is otherwise a rhetorical conflict. The embodiment of normatively framed constellations of antagonist characters is essential to this. More specifically, a conflictual relationship was crafted primarily by the composition of pictorial bodies in images of border violations, in which the attack and defense of the body connects to the emotionalizing constructs of dignity and decency.