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Gaiba, Chiara. "Blackface and Freedom of Expression." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13795/.
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With this work I would like to present the reader with a personal consideration about freedom of speech, its limits, and the controversies it has aroused, particularly in relation to the practice of blackface. The question I am trying to answer in this thesis is: should free speech be denied to those who want to use it for overt expressions of racism, such as blackface?
In regard to the structure of this thesis, I start by briefly presenting the history of free speech, from Ancient Greece, up through the French and American Enlightenment, which respectively produced the Declaration of the Rights of Man and the American Constitution. Both of these documents placed cardinal importance on freedom of speech. I then move on to argue that freedom of speech protects those who express opinions that offend, shock or disturb the state or a great part of the population. And, even most importantly, it is my belief that such opinions and expressions should not be banned nor punished. To show this, I present the case study of blackface, which is the practice of applying dark make up on a white person in order to make that person look like a black. Then, I briefly explain the history of such practice. In light of its history, black communities see blackface as extremely insulting and racist, on the one hand because it is a form of cultural appropriation, and on the other hand because it reinforces the unequal relation between Blacks and Whites, where Whites are the most powerful and decide that they have the right to mock black people.
Nowadays blackface is still persistent, and it is possible to find examples of it all over the world: in the Netherlands, with the long-standing tradition of Black Pete, in the UK, with the traditional folk dancers called The Coconutters, and finally in Japan, with many singers singing American songs in Blackface, and especially in the case of the girl band Momoiro Clover Z and the Rats and Stars’ photo in blackface before a show.
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Manning, Harriet Josephine. "Michael Jackson and the blackface mask." Thesis, University of Newcastle upon Tyne, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548013.
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O'Connor, Cheryl E. "Mother-offspring relationships in Scottish blackface sheep." Thesis, University of Edinburgh, 1991. http://hdl.handle.net/1842/15550.
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This thesis gives a complete description of the changes in the ewe-lamb relationship from birth to weaning, and determines those ewe behaviours of greatest importance to lamb survival and growth. Detailed observations on the grooming behaviour of 50 Scottish Blackface ewes illustrated the extent to which grooming behaviour in twin bearing ewes is affected by the birth of the second lamb. Althugh previous experience does not affect grooming behaviour specifically it does affect the ability of primiparous ewes to cope initially with grooming twin lambs. Previous experience does however, strongly affect ewes responses to active lambs, shown in uncooperative movement by primiparous ewes as lambs attempt to suckle. It was also found, using crossbreeding, that although a lamb, such as the Mule, may have a high birthweight and also stand quickly after birth this does not necessarily mean it will also suckle quickly and effectively. The Mule lambs which were intended to be inactive relative to pure Blackface lambs, were not in the event inactive but failed to show appropriate udder-seeking behaviour. It would appear that the initiation of grooming is genetically controlled and that lamb behaviour, particularly lamb activity may influence the further development of grooming. Longer term observations of 73 Scottish Blackface ewes and lambs outdoors in two years showed that the major changes in the ewe-lamb relationship occur at 3 weeks of age. This corresponds to the time of commencement of weaning, or a new phase in the ewe-lamb relationship and is determined by the willingness of the ewe to allow suckling and the subsequent ability of the lamb to adjust its behaviour. The lamb has to learn that it will only be allowed to suckle when the ewe communicates her wilingness by a headup or call signal. These results are discussed in relation to current literature on parent-offspring conflict and weaning theories. Ewe behavioural measures were also shown to influence lamb growth. Estimations of the quality of the ewe-lamb relationship, using measurements such as headup and call frequencies, appear most likely to have an influence on lamb survival and growth. The influence of ewe behaviour, on the lamb and the ewe-lamb relationship, may well be best investigated in the future through the use of an individual ewe 'character' description.
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Green, Joshua Lumpkin. "Digital Blackface: The Repackaging of the Black Masculine Image." Oxford, Ohio : Miami University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1154371043.
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Benothman, Mohamed Ahmed Ezzeddin. "Determinants of resistance to nematode infection in Scottish blackface sheep." Thesis, University of Glasgow, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438005.
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Fisler, Benjamin Daniel. "The phenomenology of racialism blackface puppetry in American theatre, 1872-1939 /." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2464.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2005.<br>Thesis research directed by: Theatre. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Richards, Jason. "Whites in blackface, blacks in whiteface : racial fluidities and national identities /." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010855.
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Harbord, Jack. "Representations of blackface and minstrelsy in twenty first century popular culture." Thesis, University of Salford, 2015. http://usir.salford.ac.uk/36899/.
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Blackface minstrelsy just ain’t what it used to be. This statement should not be understood as a call for the return of the minstrel show. Quite literally, minstrelsy and its central feature blackface manifest themselves in divergent ways from their nineteenth and twentieth century manifestations, convey a range of meanings, and serve a number of social and artistic functions in the twenty-first century. Through the analysis of a variety of texts and practices from across cultural fields including music, television, film, journalism, social media, and academic discourses of minstrelsy this thesis identifies how blackface and minstrelsy are manifested, their function in critical, artistic, and social contexts, and the effects of their appearance in popular culture. To achieve this, discussion utilises the analytical methodologies of semiotics and discourse analysis to identify the themes and tropes and consistencies and inconsistencies that form the image and concept of blackface minstrelsy in the twenty-first century. Initial conclusions point to a number of contrasting functions and effects: the notion of equivalency with cultural and industrial practices; use as a discursive and iconographic signifier of racism, exploitation, and marginalisation in cultural criticism; application in comedic, dramatic, and artistic contexts as a tool of satire, parody, and irony; and public displays of blackface, seemingly ignorant of its problematic signification. In conclusion, the thesis locates its findings within wider discourses of race, appropriation, and marginalisation in American society. Moreover, this is positioned in the light of recent tensions between African American communities and the police, the fiftieth anniversary of the ‘Bloody Sunday’ confrontation on the Edmund Pettus Bridge in Selma, Alabama, and the proposal of post-racialism following the election of Barack Obama as United States President in 2008.
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Conington, Joanne. "The genetic improvement of carcass and maternal traits in Scottish Blackface sheep." Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/13453.
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This thesis addresses the issues of genetic improvement of carcass and maternal traits in hill sheep. It i) compares the performance of two genetic lines of Scottish Blackface lambs divergent for subcutaneous fat, ii) quantifies the genetic components of carcass traits in extensive hill environments, iii) explores the implications of selecting for reduced fatness in hill lambs, iv) develops and describes methods to include carcass traits in the breeding goals for hill sheep, and v) gives predicted results from index selection for maternal and carcass traits, using indexes of overall economic merit. For points i) to iii), approximately 2000 Scottish Blackface lambs were measured, sired by 32 rams divergent for subcutaneous fat depth, and born to 1660 unselected ewes in 1991 and 1992. They were reared under extensive conditions on two contrasting hill farms. Results showed that genetic differences in subcutaneous fatness arising from selection in an intensive environment are still expressed despite harsh rearing environments. Heritabilities for birth weight, marking weight (at approximately 6 weeks of age) and weaning weight (at 17 weeks) were 0.07±0.04, 0.02±0.03, and 0.14±0.05, respectively. Heritabilities for ultrasonic muscle and fat depth were 0.27±0.09 and 0.16±0.06, respectively. Heritability estimates for carcass traits were: pre-slaughter liveweight 0.36±0.13, cold carcass weight 0.39±0.14, fat class 0.13±0.08, conformation score 0.09±0.07, dissected lean weight 0.27±0.27, dissected bone weight 0.36±0.13 (constant subcutaneous fatness), dissected intermuscular fat weight 0.10±0.07, subcutaneous fat weight 0.20±0.09 (constant cold carcass weight). There was a strong maternal effect on live weight which declined with age. The rearing environment of the lambs was an important environmental effect on the heritability estimate for backfat thickness, being twice as large for animals reared on the improved pasture compared to those reared on hill pasture.
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Rosby, Amy. "Subverting blackface and the epistemology of American identity in John Berryman's 77 Dream songs." Cleveland, Ohio : Cleveland State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1216665711.
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Thesis (M.A.)--Cleveland State University, 2008.<br>Abstract. Title from PDF t.p. (viewed on Nov. 7, 2008). Includes bibliographical references (p. 50-52). Available online via the OhioLINK ETD Center. Also available in print.
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Wassink, Geert Jan. "The effect of nutrition on the pathophysiology of trypanosomiasis in Scottish Blackface sheep." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363165.
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Byrne, Kevin. "The Tautology of Blackface and the Objectification of Racism: A “How-To” Guide." ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2016. http://hdl.handle.net/10150/621513.
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This essay examines U.S. blackface performance in the twentieth century through the lens of Adorno's mass culture critiques, specifically of jazz music. Despite being rooted in the divisive logic of antiquated live performance traditions, blackface as a racist glyph flourishes in the technologically mediated social environment of the twentieth century. By replacing Adorno's critique of jazz with a direct investigation of blackface, the essay argues for a more materialist approach to minstrelsy studies that acknowledges both circulation and accumulation as oppressive hegemonic forces.
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Lambe, Nicola Ross. "An investigation of tissue mobilisation in Scottish Blackface ewes using X-ray computer tomography." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/12113.
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This thesis reports on an investigation of seasonal changes in tissue levels in Scottish Blackface hill ewes throughout their reproductive lifetime. X-ray computed tomography (CT) scanning was used to produce accurate estimates of total body weights of muscle, carcass fat and internal fat. Seasonal tissue changes, estimated from CT measurements, were then investigated during one annual cycle, in ewes producing different numbers of lambs. Carcass fat (subcutaneous and intermuscular) and internal fat depots were depleted during pregnancy and early lactation and repleted from mid-lactation to mating the next year. Muscle was mobilised only when fat reserves were severely depleted. Genetic parameters were estimated for fat (carcass and internal) and muscle weights during the first production cycle of ewes (at pre-mating, pre-lambing, mid-lactation, weaning and pre-mating the following year), and for total tissue weight loss (pre-mating to mid-lactation) and weight gain (mid-lactation to pre-mating). Heritabilities were moderate to large for most traits except total tissue weight gain of fat and muscle, which showed little genetic variation. Genetic and phenotypic correlations with lamb production traits were then investigated. Muscle weight in the ewe throughout the production cycle, and internal fat weight at events before lambing, tended to be positively correlated with number of lambs born and total weaning weight of lambs. No clear relationships were apparent between total carcass fat weight and lamb production traits. Moderate to large genetic correlations were estimated between weight loss from each tissue and total weights of lambs reared to mid-lactation or weaning. Changes in tissue levels were modelled over the reproductive lifetime of ewes using random regression, and genetic and phenotypic parameters estimated at different time-points. Heritabilities were moderate to high for each tissue and were highest during mating for fat weights, and during the dry period and at lambing for muscle weights. Tissue levels in the ewe were affected by the number of lambs produced in the current and previous years and this effect increased as ewes aged. Correlations were estimated for ewe tissue weights throughout their reproductive lifetime (modelled using random regression) with total weights and growth rates of lambs produced. Genetic correlations with lamb growth traits were moderate to large and positive for muscle weights throughout the productive lifetime of the ewe, and small to moderate and positive for internal fat weights. The findings from these analyses have implications for hill sheep breeding programmes. To achieve the aims of increasing litter weights at weaning whilst improving carcass quality, it may be preferable to increase muscle weight in the ewe flock, decrease carcass fat weight and maintain, rather than reduce, internal fat.
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Mossakowski, Tomasz Filip. ""The sailors dearly love to make up" : cross-dressing and blackface during polar exploration." Thesis, King's College London (University of London), 2015. http://kclpure.kcl.ac.uk/portal/en/theses/the-sailors-dearly-love-to-make-up-crossdressing-and-blackface-during-polar-exploration(6d15743a-5976-4ea1-bf7f-a707b999590f).html.
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This research project writes against the hegemonic narratives of polar exploration in the nineteenth and early twentieth centuries. Using the published and unpublished diaries of explorers from 1819 to 1904, it asks how queer, critical race and postcolonial critiques of the hyper-masculine, all-white image of the polar explorer can open up new understandings of polar spaces both in the nineteenth century and today, when similar nationalistic, colonial enterprises are at play. Primarily informed by Lisa Bloom’s feminist, postcolonial review of American ideologies of polar exploration, this project discusses the large disparity between the intensely masculine image of the polar hero-adventurer and the particularly Anglo-American, but also Norwegian, tendency to perform drag during polar expeditions. It also examines the high incidence of blackface theatre: in one of the whitest spaces conceivable, sailors donned the black mask to air a complex constellation of white, colonial and class grievances and aspirations. Polar performance, which evolved to have its own idiosyncrasies shaped by the natural and social polar environment, affected colonial relations with Inuit, the stuff of farce being pressed into the service of imperial force. Indigenous populations witnessed grotesque displays of Anglo-American gendered and racial values through theatrical recreation, while simultaneously resisting the encroachment of expedition society through similar but seemingly smaller avenues of performative resistance. Broadly speaking, this project offers this more radical, revisionist interpretation at a time when interest in the Arctic and Antarctic is soaring due to anthropogenic climate change. It challenges the current reappropriation of heroic, hyper-masculine figures by national andprivate interests through celebrating their lesser-known but equally fascinating mid-winter activities.
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Miller, Benjamin Ian English Media & Performing Arts Faculty of Arts & Social Sciences UNSW. "The Fantasy of Whiteness: Blackness and Aboriginality in American and Australian Culture." Awarded By:University of New South Wales. English, Media, & Performing Arts, 2009. http://handle.unsw.edu.au/1959.4/44584.
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This dissertation argues that a fantasy of white authority was articulated and disseminated through the representations of blackness and Aboriginality in nineteenth-century American and Australian theatre, and that this fantasy influenced the representation of Aboriginality in twentieth-century Australian culture. The fantasy of whiteness refers to the habitually enacted and environmentally entrenched assumption that white people can and should superintend the cultural representation of Otherness. This argument is presented in three parts. Part One examines the complex ways in which white anxieties and concerns were expressed through discourses of blackness in nineteenth-century American blackface entertainment. Part Two examines the various transnational discursive connections enabled by American and Australian blackface entertainments in Australia during the nineteenth century. Part Three examines the legacy of nineteenth-century blackface entertainment in twentieth-century Australian culture. Overall, this dissertation investigates some of the fragmentary histories and stories about Otherness that coalesce within Australian culture. This examination suggests that representations of Aboriginality in Australian culture are influenced and manipulated by whiteness in ways that seek to entrench and protect white cultural authority. Even today, a phantasmal whiteness is often present within cultural representations of Aboriginality.
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Forssell, Amanda. "Lilla Hjärtats två ansikten : En diskursanalys av debatten om en barnboksfigur." Thesis, Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-36574.
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In the autumn of 2012 the fictional character “Lilla Hjärtat” created by the Swedish author and illustrator Stina Wirsén, became a much-discussed topic in Swedish media. This following the premiere of the children’s film “Liten Skär och alla små brokiga”. Stina Wirsén is an established and well-acclaimed name in children’s literature. “Lilla Hjärtat”, a jet-black doll, had become one of many popular characters in her books. However, two years later at the time of the film release, social media picked up on the idea that “Lilla Hjärtat” resembled a racist stereotype, a so-called picaninny or a blackface. According to Wirsén, her intention was to deflate an outdated stereotype and refill it with a new and positive meaning. The purpose was to offer children of all skin colours and all backgrounds an empowering role model to identify with. Those who were opposed argued that using a racist stereotype in a children’s book or film was inappropriate and harmful. On the other hand, those in favour did not view the character as racist and believed it would contribute to openness and diversity. The purpose of the thesis is to make an analysis of the debate and the arguments that were presented. As a result I could find two discourses, one that argued against “Lilla Hjärtat”, and one that argued that “Lilla Hjärtat” was a positive character. In the discourse against Lilla Hjärtat, debaters maintained that small children were unable to distinguish between the different meanings of stereotypical pictures, and also that a privileged white person does not have the interpretative prerogative to change a stereotypical image that has been discriminating black people for generations. In the other discourse, debaters meant that the character could be an important and strong role model for young dark-skinned children. They also discussed that the real problem was that there were so few characters of children of other nationalities in children’s literature.
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Smith, Alicia Jean. "A historical analysis of blackface in the media and its effects on contemporary African American stereotypes." Scholarly Commons, 2004. https://scholarlycommons.pacific.edu/uop_etds/2735.
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The purpose of this study was to explore and expose racial stereotypes of African Americans in the mass media. The research was conducted as a historical analysis using historical artifacts from as early as 1619. These historical artifacts include journal articles, books, websites, research papers, and films that are both explanation pieces and examples of black stereotypes. All of the historical artifacts were found through Internet search engines and article databases including the University of the Pacific's library database. Other materials given to pinpoint information for this study were also given by University of the Pacific professors. All of the information was examined and synthesized into this study. In order to expose and uncover past and contemporary African American stereotypes, the historical information collected for this study was organized. The results revealed three categories: (1) the initial stereotypes that blackface created, (2) the extent to which initial racial stereotypes affect today's status of African American depictions and, (3) the occurrences of blackface in today's contemporary media. This historical analysis provides a rich background to past stereotypes of African Americans as well as develops a framework for critiquing the status of black stereotypes in today's contemporary media. The analysis of the historical artifacts found that the initial depiction of blackface (one of the original forms of African American stereotypes) is not necessarily a thing of the past. In addition this study concluded that the initial stereotypes of African Americans have not only influenced the African American depictions of today but also that in many ways the portrayals are the same and just “packaged” differently.
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Barnes, Rhae Lynn. "Darkology: The Hidden History of Amateur Blackface Minstrelsy and the Making of Modern America, 1860-1970." Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493592.
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Darkology: The Hidden History of Amateur Blackface Minstrelsy and the Making of Modern America, 1860-1970 develops a critical bibliography and uses material culture to uncover the pervasive world of amateur blackface minstrelsy that took hold in most cities in the United States North and West between 1860 and 1970. Previously lost to history, amateur minstrelsy was integral to domestic and international imperialism. This dissertation aims to understand the cultural origins and consequences of amateur blackface minstrelsy, to map its political geography, and recapture the significance of its print culture. Despite an abundant body of evidence, the print culture of amateur blackface had remained unstudied. Darkology discloses the relationship between racially exclusive fraternal orders and the U.S. Government, and the immense body of blackface print that they created for public use. Darkology reveals the lost history of amateur blackface by providing the first bibliographic study of amateur blackface print, extends the chronology of theatrical blackface minstrelsy by seventy years through 1970, expands the geography of blackface in amateur form to the West, and reveals legal campaigns waged by the NAACP to ban blackface during the Civil Rights Movement.<br>History
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Willis, Corin Charles. "The signifier returns to haunt the referent : blackface and the stereotyping of African-Americans in Hollywood early sound film." Thesis, University of Warwick, 2002. http://wrap.warwick.ac.uk/55891/.
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This thesis investigates the persistence of blackface in Hollywood's early sound era 1927-1953. It establishes the extensive and complex nature of this persistence against previous historical accounts of its decline after the introduction of sound. Specifically this thesis considers the overlooked phenomenon of co-presence where blackface was juxtaposed with the increased visibility of African-Americans in Hollywood film. It argues that the primary historical significance of the persistence of blackface lies in its involvement in, and exposure of, the formal stereotyping of African Americans in film. The thesis is founded on research which identified 124 blackface films and on viewings of 75 of these films. Primarily the argument is advanced on the basis of close textual analysis. In addition to its theoretical engagement with key positions on blackface and related areas the thesis also makes use of secondary sources in order to establish the historical context behind its persistence in film. Principle areas discussed include the formal practices used to racially mark African Americans in film, co-presence in the films of Al Jolson and Eddie Cantor, and blackface and the racial containment of African-American vernacular dance and music. This thesis contributes to an understanding of the place of blackface in Hollywood history by setting down what is, to the best of its author's knowledge, the most extensive account to date of its persistence in the early sound era. In doing so it brings new material to the debates on the 'nature' of blackface and argues that current attempts to revise understandings of its racial bias may be misguided. In conclusion this thesis finds that the case study of co-presence indicates that one explanation for the longevity of Hollywood's African-American stereotypes lies in the sheer density of their textual construction.
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Abuargob, Omry Milad. "Validation of genetic and phenotypic markers and the difference between the sexes on nematode infection in Scottish blackface lambs." Thesis, University of Glasgow, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437963.
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Wilcox, Charleen M. "Constructing Asian/American Women on Screen." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/communication_theses/68.
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Asian/American women occupy a highly circumscribed subject position in popular Western culture that entails a unique reading of our bodies. My discussion of this group will gain greater depth and scope by using Black body theory as a theoretical framework to better understand how Asian/American bodies become a site to enact a multitude of fantasies, fears, and anxieties. I will examine three case studies: the construction of the interracial “romance” featuring Asian/American women produced in classical Hollywood cinema, interracial pornography featuring Asian/American female performers, and the independent works of Asian/American feminist filmmakers. Topics interrogated include the over-determination of non-White bodies and possibilities for destabilizing bodies and crafting their new legibility.
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Park, Michael. "A study on variation in immune responses and protective mechanisms to Ostertagia circumcincta and their relationship with parasitological parameters in Scottish blackface sheep." Thesis, University of Glasgow, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392604.
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Henderson, Neil Gordon. "Immunity to Teladorsagia circumcincta infection in Scottish blackface sheep : an investigation into the kinetics of the immune response, antigen recognition and the MHC." Thesis, University of Glasgow, 2002. http://theses.gla.ac.uk/4140/.
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The kinetics of the host's immune responses to challenge infection were studied and identified clear patterns in plasma IgA activity, peripheral eosinophil counts, faecal egg counts and plasma pepsinogen concentrations but not in plasma IgG activity. It was determined that when used in parallel and when tested at multiple time points, these parameters have much greater potential as markers of resistance than when used individually or more importantly if only assessed on a single occasion. Further work investigated the recognition of stage specific parasite antigens by host plasma IgA by Western blotting. After adjusting for differences in the activity of IgA in each plasma sample the work in this thesis identified that preferential recognition of a different set of antigens was associated with resistance in the group of experimentally challenged animals compared to previous publications. Additionally, and for the first time this investigation was also carried out on naturally infected animals. There was little correlation in the patterns of antigen recognition between the experimentally challenged and naturally infected animals. Finally, the role of MHC was investigated and it was determined that MHC heterozygotes produced significantly more plasma IgA then MHC homozygotes but did not harbour significantly shorter worms. The analysis also confirmed in naturally infected sheep that there was no obvious relationship between MHC polymorphism and antigen recognition. The results suggested that resistance was due to the recognition of several molecules rather than a single molecule. The work detailed in this thesis has further increased our understanding of the complex host/parasite relationship and has confirmed that selective breeding using the various phenotypic and genetic markers studied is possible. However, this will only be viable if the tests involved in assessing these traits become cheaper and easier to perform, especially if they are to be carried out by the farmer, on the farm.
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Scal, Joshua. "White Skin, Black Masks: Jewish Minstrelsy and Performing Whiteness." Scholarship @ Claremont, 2019. https://scholarship.claremont.edu/cmc_theses/2163.
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This work traces the relationship of Jews to African-Americans in the process of Jews attaining whiteness in the 20th century. Specific attention is paid to blackface performance in The Jazz Singer and the process of identification with suffering. Theoretically this work brings together psychoanalytic theories of projection, repression and masochism with afro-pessimist notions of the libidinal economy of white supremacy. Ultimately, I argue that in its enjoyment and its masochism, The Jazz Singer empathizes with blackness both as a way to assimilate into white America and express doubt at this very act.
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Brown, Maya Olivia. "EMPOWERMENT THROUGH ACKNOWLEDGEMENT:CONTEMPORARY STRING BANDS AND THE BLACK ROOTS MUSIC REVIVAL." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1532894230322707.
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Ward, Perry K. "A SELECT SURVEY OF CHORAL ARRANGEMENTS BASED ON THE SONGS OF STEPHEN FOSTER TRACING DEVELOPMENTS IN MUSIC AND TEXTUAL CHANGES THROUGH THE TWENTIETH AND TWENTY-FIRST CENTURIES." UKnowledge, 2017. https://uknowledge.uky.edu/music_etds/103.
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Stephen Foster is acknowledged as America’s first composer of popular music. His legacy can be seen in the number of songs that are embedded in our cultural heritage – “Oh! Susanna,” “Beautiful Dreamer,” and “My Old Kentucky Home,” are but a very few of his most popular works. Stephen Foster’s songs have been incorporated into every facet of American culture including both popular and classical musical culture, television, and film. However, his legacy is complicated as it is tainted by connections to blackface minstrelsy in some works. This document seeks to trace the threads of racial sensitivity and cultural appropriation in works arranged for choral ensembles based on Foster’s songs. The arrangements chosen for this document provide a glimpse into three distinct periods of American history – pre-Civil Rights, the Civil Rights Era, and post-Civil Rights. Using a process of comparative analysis of the music and text of the originals to that of the arrangements, this document traces expected and unexpected changes in music and text associated with each period. Perhaps through the continued study of one of America’s first purveyors of popular culture, we can begin to understand our national legacy of racism more clearly and find a path towards reconciliation.
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Sevel-Sørensen, Simone. "Racial Performances On Social Media - A study of the Sweet Brown memes." Thesis, Malmö universitet, Fakulteten för kultur och samhälle (KS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-23997.
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Abstract:Social Media has become a powerful tool in several aspects. It can mobilize movements, rallying for social or political causes, and it can bring people together to share experiences or interest on a global platform. Social media platforms have facilitated more dynamic ways of presenting and performing identity positions such as race, gender, class and sexuality. Though many scholars have agreed that the internet and social media offer interesting new aspects in relation to identity exploration and self-expression, the performance of identity online can also contribute to problematic discourses that reinforce old social stereotypes online affecting what happens offline.This thesis explores racial performance on social media by examining the phenomenon of ‘Digital Blackface’, which is a virtual continuation of a historical phenomenon that operates, in particular, through Internet memes. The thesis studies different versions of an American meme, which represent an altered representation of a real person, known as Sweet Brown. Sweet Brown is an African American woman who after she was interviewed on television became a viral celebrity. Due to her expressive personality, her image has been remixed into several popular Internet memes.The theoretical framework consists of a theorization of racial performance and media representation theory. This theoretical lens is used in the analysis that sets out to answer the questions, how is the Sweet Brown meme used as a form of racial performance online? What is Digital Blackface and how does it operate online? And In what way can racial performance reinforce stereotypic representations? The methodological approach the thesis employs to conduct the analysis and exemplify the problematics are visual analysis, critical discourse analysis, and critical theory. Further, the implication of racial performances in Internet memes is linked to other recent cases or incidents that relate to issues of racial performance in the media. Keywords: Racial Performance, Internet memes, Minstrelsy, Digital Blackface, Internet Culture, Representation, Race, Racism.
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Freitas-Fernandes, Aurélien. "Le Concert Party hier et aujourd’hui en Afrique de l’ouest : une enquête de terrain (évolution histoire, question dramaturgiques, enjeux esthétiques et sociologiques)." Electronic Thesis or Diss., Paris 3, 2023. http://www.theses.fr/2023PA030030.
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Cette thèse en Études théâtrales, assortie d’un film scientifique documentaire, s’appuie sur une enquête de terrain aussi historique qu’anthropologique qui vise à comprendre les enjeux dramaturgiques et sociologiques d’un genre de Cabaret-Théâtre musical nommé le Concert Party. De ses origines aux temps de la colonisation, jusqu’à nos jours, le Concert Party s’est inscrit en Afrique de l’Ouest comme un mouvement artistique extrêmement populaire et subversif. Produits en langue vernaculaire (twi, ewe, mina…), associés à de la musique Highlife et s’appuyant sur des travestissements, des maquillages et une dramaturgie extrêmement codés, les spectacles se jouent encore dans les maquis des grandes et moyennes villes de la côte ouest-africaine et s’amusent avec dérision à retourner les représentations coloniales et racistes tout en résistant à l’aliénation culturelle et aux pouvoirs politiques. Né en 1930 en Gold Coast (aujourd’hui le Ghana), le genre s’est exporté, après les Indépendances, vers son pays voisin le Togo en 1965. Mais le genre va connaître dans ces deux pays un destin bien différent, sans perdre pour autant sa force subversive. La recherche, qui s’attache à l’histoire et aux mutations du genre jusqu’à son devenir actuel, est adossée à un travail d’investigation entrepris lors de plusieurs séjours au Ghana et au Togo, ainsi qu’à des expériences de terrain faites de l’intérieur. Elle a en effet été menée, entre autres, en immersion au sein de l’Azé Kokovivina Concert Band, la dernière grande compagnie de Concert Party du Togo, créée en 1985. Ce qui a également permis de réaliser un collectage d’archives, de témoignages et de traces vidéo sous la forme d’un reportage scientifique<br>This thesis in Theatre Studies, accompanied by a scientific documentary film, is based on a historical and anthropological field study that aims to understand the dramaturgical and sociological issues of a genre of musical cabaret theatre called the Concert Party. From its origins during the colonial period to the present day, the Concert Party has been an extremely popular and subversive artistic movement in West Africa. Produced in the vernacular (Twi, Ewe, Mina...), associated with highlife music and relying on highly coded disguises, make-up and dramaturgy, the shows are still performed in the maquis of the large and medium-sized cities of the West African coast and derisively enjoy turning colonial and racist representations on their head while resisting cultural alienation and political powers. Born in 1930 in the Gold Coast (now Ghana), the genre was exported to its neighbouring country Togo in 1965 after independence. However, the genre's fate in these two countries was very different, without losing its subversive force. The research, which focuses on the history and mutations of the genre up to its present day, is based on research undertaken during several visits to Ghana and Togo, as well as on field experiences from the inside. It was carried out, among other things, by immersion in the Azé Kokovivina Concert Band, Togo's last great concert party company, created in 1985. This also made it possible to collect archives, testimonies and video traces in the form of a scientific report
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Cras, Pierre. "Archétypes, caricatures et stéréotypes noirs du cinéma d'animation américain du XXe siècle (1907-1975)." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCA153.
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Cette thèse porte sur les notions d'archétypes, caricatures et stéréotypes et leurs applications aux personnages noirs dans le film d'animation américain du XXe siècle. C'est en 1907 qu'est diffusé aux Etats-Unis le tout premier film d'animation mettant en scène un personnage noir. Ce dernier, appelé coon, était l'héritier d'une longue tradition de représentations péjoratives qui visaient à maintenir les Noirs dans une position d'altérité et d'infériorité face aux Blancs. Les premiers exemples de ces représentations se retrouvent notamment dans le comic strip américain dont les artistes ont d'abord été dessinateurs, puis « animateurs ». Toutefois, une grande partie des traits physiques et de l'idéologie qui sous-tendent à la création de ces personnages avait déjà été déterminée au XIXe siècle par des disciplines pseudo scientifiques consacrant « l'infériorité » des Noirs sous couvert d'une fausse science, surtout la physiognomonie et la phrénologie, des disciplines émettrices de ce type d'observations et de dessins qui connurent un succès important aux Etats-Unis après avoir été diffusées en Europe. Une autre source d'influence dans l'édification des stéréotypes noirs des films d'animation est celle du spectacle vivant, en particulier les numéros de vaudeville et du Blackface (spectacles populaires de la fin du XIXe siècle aux années 1960 durant lesquels des comédiens blancs grimés en Noirs parodiaient ces derniers). Les personnages noirs du cinéma d'animation reprenaient ces trois influences dont les traces sont largement perceptibles jusqu'aux années 1940. Les représentations péjoratives des Noirs dans l'animation évoluent lentement à partir de 1941 et la conscription des soldats Africains-Américains durant la Seconde Guerre mondiale. Bien qu'une majorité de films d'animation continuent de mettre en scène des personnages caricaturaux, des changements commencent à poindre légèrement, notamment à travers l'exploitation de la musique bebop. L'après-guerre marque une transition définitive entre anciennes caricatures et nouvelles représentations. La montée des revendications des Africains-Américains en faveur d’une égalité de traitement créé une ambivalence entre leurs velléités réformatrices et la persistance d'archaïsmes dépréciatifs dans le cinéma d'animation. Au gré des avancées sociales obtenues par le Mouvement pour les Droits Civiques et du combat mené par les partisans du Black Power, les personnages noirs du cinéma d'animation, puis du dessin animé télévisuel intègrent ces nouvelles dynamiques positives mais également conformistes, parfois déconnectées des réalités des Africains-Américains. Les représentations les plus en adéquation avec leur époque proviennent finalement du milieu du film d'animation underground des années 1970 où se côtoient prostituées et bonimenteurs autour d'un sous-texte social inédit<br>This thesis focuses on the notions of archetypes, caricatures and stereotypes as well as their application to black characters in twentieth-century American animated films. In 1907, the very first animated film depicting a black character, “Coon”, was screened. “Coon” came from a long tradition of pejorative depictions that targeted African Americans and defined them down as “others” and “inferiors”. The first regular examples of these representations emerged in American comic strips and were drawn by cartoonists who soon became “animators”. A large part of the ideology and physical representations leading to the creation of these characters was inspired by pseudo-scientific theories that sanctioned black people “inferiority”, graphically and ideologically in the name of pseudo-sciences, including first and foremost physiognomy and phrenology, which first gained influence in Europe before reaching the United States. Vaudeville and Blackface Minstrelsy performances – popular shows that lampooned Black people and were performed by white actors in make-up from the end of the nineteenth century to the 1960s – also played a significant role in the creation of black otherness. The black characters in animated films were a reflection of these three cultural influences and remained unchanged until the 1940s. The negative depictions of African Americans in animated films began to evolve slowly when the United States entered World War II. Slow changes were perceptible through the use of bebop music in such films, although the vast majority of those films remained full of caricatures of Black people. Irrevocable changes rose in the post-war period, from old caricatures to new representations. Increasing demands by African Americans for equal rights created an ambiguity between their integrationist aspirations and the remaining visual traces going back to the period of slavery. The gradual legal gains achieved through their fight in the Civil Rights and Black Power movements led to a new televisual and cinematic imagery, which showed more positive sides of Blackness, despite the persistence of a conformist tone, sometimes out of touch with African American reality. The most faithful reflections of African American experience ultimately came from underground animated movies in the 1970s, in which prostitutes and hustlers added to a new social subtext
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Ohene-Abuakwa, Yaw. "In vitro erythroid model for diamond blackfan anaemia." Thesis, St George's, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420364.
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Britz, Andreas. "Hidden in Plain Sight: John Berryman and the Poetics of Survival." Ohio University Honors Tutorial College / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1274991004.
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Fröjmark, Anne-Sophie. "Molecular Studies of Diamond-Blackfan Anemia and Congenital Nail Dysplasia." Doctoral thesis, Uppsala universitet, Institutionen för genetik och patologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-128067.
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The aim of this thesis is to investigate the effect of genetic mutations on the pathophysiology of two human disorders: Diamond-Blackfan Anemia (DBA) and isolated congenital nail dysplasia. The first part of this thesis (Paper I-III) investigates the mechanism associated with DBA. DBA is a rare bone marrow failure syndrome characterized by the absence or decrease of erythroid precursor cells. The disease is further associated with growth retardation, malformations, predisposition to malignant disease and heterozygous mutations in ribosomal protein (RP) genes. The second part of this thesis (Paper IV) investigates the genetic basis of isolated autosomal recessive nail dysplasia characterized by pachyonychia and onycholysis of both finger- and toenails. It further dissects the molecular mechanisms regulating nail development. In the first study, we investigated the previously reported RPS19/PIM-1 interaction by generating a combined Rps19/Pim-1 knockout mouse model. We found that allelic Rps19 insufficiency and Pim-1 deficiency have a cooperative effect on murine hematopoiesis resulting in increased myeloid cellularity associated with cell cycle alterations and reduced apoptosis. In the second study, we analyzed primary fibroblasts from DBA patients with truncating mutations in RPS19 or RPS24 and observed a marked delay in cellular growth associated with specific cell cycle defects. In the third study, we discovered that recombinant RPS19 binds its own mRNA and that the binding is altered when two DBA-associated RPS19 mutations are introduced. In the fourth study, we identified mutations in the WNT signaling receptor Frizzled 6 (FZD6). We observed that the nonsense mutant fails to interact with the first downstream effector Dishevelled. Fzd6 mutant mice displayed claw malformations and we detected a transient Fzd6 expression in the distal digits at the embryonic time point for nail development. In summary, this thesis elucidates several mechanisms in the etiology of DBA and congenital nail dysplasia and mechanisms regulating nail development.
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Childs, Alundra Nicole. "La Tradicion de Los Negros Lubolos: ¿Es Una Apreciacion o Una Apropiacion del Candombe?"." Miami University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=miami1496097078570828.
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Badhai, Jitendra. "Ribosomal proteins in diamond-blackfan anemia Insights into failure of ribosome function /." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-110070.
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Marius, Carine Gisele. "Erythroid transcriptional pathophysiology in diamond blackfan anaemia and the effects of steroids." Thesis, St George's, University of London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502468.
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Saby, Manon Juliette. "Identification de gènes candidats pour l'anémie de Blackfan-Diamond et caractérisation phénotypique." Thesis, Université de Paris (2019-....), 2019. https://theses.md.univ-paris-diderot.fr/SABY_Manon_va2.pdf.
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L’anémie de Blackfan-Diamond (ABD) est une érythroblastopénie congénitale rare secondaire à un blocage de la maturation des cellules érythroïdes entre les stades BFU-e (EPO indépendant) et CFU-e (EPO dépendant). La maladie se manifeste par une anémie arégénérative, le plus souvent macrocytaire. Dans 50% des cas, à l’anémie s’associe un syndrome malformatif affectant l’aire céphalique et les extrémités et incluant un retard de croissance. Bien que très hétérogène tant phénotypiquement que génotypiquement, l'ABD est due à des mutations toujours hétérozygotes dans des gènes de protéines ribosomiques (RP) pour 80% des cas. Le premier gène identifié comme impliqué dans l’ABD est le gène de la RPS19 (RPS19), faisant de l’ABD la première ribosomopathie décrite. A ce jour, 20 gènes de RP ont été identifiés. L'haplo-insuffisance en RP entraîne un défaut de maturation des ARN ribosomiques (ARNr) générant un stress nucléolaire, qui lui-même conduit à la stabilisation de la protéine p53. La p53 stabilisée induit l’apoptose et l'arrêt du cycle cellulaire qui sont responsables en grande partie de l’érythroblastopénie. Plus rarement, l’ABD peut être la conséquence de mutations présentes sur le gène GATA-1 (facteur de transcription majeur de l’érythropoïèse), le gène TSR2 (interagissant avec la protéine RPS26 et intervenant dans la biogenèse des ribosomes) ou encore le gène EPO (cytokine clé de l’érythropoïèse). Cependant, 20% des patients atteints d’ABD ne sont toujours pas génotypiquement diagnostiqués : de nouveaux gènes candidats sont encore à découvrir chez ces patients. Dans cette perspective, l’objectif de ma thèse a donc été de caractériser le rôle fonctionnel de nouveaux gènes candidats afin de confirmer leur lien avec l’ABD. Nous avons procédé à un séquençage d’exomes chez 25 familles ce qui a permis d’identifier 8 gènes candidats. Nous présentons ici quatre de ces gènes dont deux gènes codant pour un chaperon ribosomique : HSPA14 et HEATR3, un gène codant pour une RP : RPL9 et un gène codant un facteur de croissance : CECR1.Les protéines chaperons du ribosome représentent un nouveau groupe de gènes pouvant être associé à la maladie. Mes travaux de thèse ont permis d’étudier la prolifération, la division, l’amplification, la différenciation et la viabilité des cellules primaires érythroïdes issues des patients porteurs de variations alléliques dans ces gènes. Ces expériences ont permis de mettre en évidence un défaut de prolifération érythroïde chez l’ensemble des patients testés accompagné d’une diminution de l’amplification et de la division cellulaire ainsi qu’un retard de différenciation. Ces résultats sont objectivés par la persistance des marqueurs d’immaturité CD34 et IL-3R ainsi que d’un retard d’apparition des marqueurs terminaux tels que la BAND3 ou l’alpha4-intégrine. L’étude transcriptionnelle et protéique met en évidence une stabilisation de p53, conduisant à une activation de ces cibles p21 et de bax. Le travail est finalisé pour HEATR3 (manuscrit en préparation) et en cours de finalisation pour HSPA14.L’étude sur le gène RPL9 grâce à un travail collaboratif a permis de mettre en évidence deux phénotypes différents en fonction du variant allélique identifié : un phénotype ABD pour un variant allélique de la 5’UTR ou un phénotype associé à un risque de cancer. L’étude de la différenciation érythroïde montre un impact sur la différenciation et la prolifération pour le variant lié à l’ABD uniquement. Parallèlement, une étude en collaboration sur le gène RPL13, a permis de confirmer le rôle spécifique de certaines protéines RP dans d’autres pathologies que l’ABD et d’ajouter une nouvelle maladie à la liste des ribosomopathies.Le facteur de croissance CECR1, identifié comme muté chez plusieurs familles du consortium EURODBA, représente un nouveau groupe de gènes pouvant être associés à la maladie<br>Diamond-Blackfan anemia (DBA) is a congenital rare erythroblastopenia due to a blockage in the maturation of erythroid cells between the BFU-e and CFU-e stages. DBA is characterized by an aregenerative, usually macrocytic, anemia, associated with the total absence or less than 5% of erythroid precursors in the bone marrow. In 50% of DBA cases, anemia is associated with congenital malformations affecting the cephalic area and the extremities of the limbs and a growth delay. The DBA phenotype and genotype are heterogeneous, however a mutation in a ribosomal protein (RP) gene, always at heterozygous state, is found in 80% of cases. Up to date, 20 RP genes have been associated with DBA pathophysiology, establishing DBA as the first identified ribosomopathy. Mutations of these RP induce a defect in rRNA maturation. Therefore, for ribosome dysfunction, cell cycle arrest and p53-mediated apoptosis induction are responsible for erythroblastopenia in patients. More rarely, DBA may be the consequence of mutations present on a non-PR gene: the GATA-1 gene (major transcription factor of erythropoiesis), the TSR2 gene (interacting with the RPS26 protein and involved in ribosome biogenesis) or the EPO gene (erythropoiesis key cytokine) have been identified so far. However, 20% of the DBA patients are still not genotypically diagnosed, leaving room for the discovery of new candidate genes. In this perspective, the aim of my PhD was therefore to identify new candidate genes involved in DBA etiology and characterize their functional roles of in order to confirm their link with DBA. For this purpose, we sequenced exomes on 25 families and identified 8 candidate genes. In this manuscript, I will present my work as part of a bigger project to validate four new genes involved in BDA pathophysiology.RPL9 is a RP of the large 60S ribosomal subunit. Mutations in this gene lead to two different phenotypes depending on the allelic variant: a DBA phenotype for an allelic variant of the 5' UTR or a phenotype associated with a cancer risk. As part of a collaborative work that compared the two RPL9 variants, I showed that the DBA variant only has an impact on erythroid differentiation Compared to a healthy individual, patients presenting the DBA variant exhibit a reduced proliferation rate and a delay in the acquisition of erythroid markers. P53-dependent activation of p21 in those cells is most likely responsible for the cell cycle arrest. Activation of caspases sign an induction of apoptosis and is consistent with the reduced viability of erythroid progenitors. A collaborative study on the RPL13 gene confirmed the specific role of certain RP proteins in non-DBA diseases and added a new disease to the list of ribosomopathiesXRibosome chaperone proteins represent a new group of genes that may be associated with DBA. I investigated the proliferation, division, amplification, differentiation and viability of primary erythroid cells from patients with allelic variations in one of these genes: HEATR3. These experiments revealed a lack of erythroid proliferation, with a defect in cell division. The mRNA and protein quantifications showed a stabilization of p53, leading to an activation of its targets: p21, controlling cell cycle, and Bax, involved in apoptosis induction. We also observed a delay in differentiation with the persistence of CD34 and IL-3R immaturity markers and a delay in the appearance of terminal markers such as BAND3 or alpha4-integrin. The role of HSP70 controlling GATA1 localization in early stages of the erythroid differentiation was recently elucidated. In this work, I identified as a new candidate gene for DBA, a HSP70 family member, HSPA14, and I characterized the defects in erythroid differentiation induced by this variant. Furthermore, I was able to identify an association of DBA with a variant in CECR1 gene encoding an adenosine deaminase in several families of the EURODBA consortium
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Gastou, Marc François Philippe. "Rôle de la protéine HSP70 au cours de l'anémie de Blackfan-Diamond." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC231/document.
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L’anémie de Blackfan-Diamond (ABD) est une érythroblastopénie congénitale rare, secondaire à un blocage de la maturation érythroïde entre les stades BFU-e et CFU-e. L’ABD est le plus souvent la conséquence d’une mutation germinale affectant un gène codant pour une protéine ribosomique (RP) de la petite ou de la grande sous-unité du ribosome. Quatorze gènes distincts ont été identifiés. Les gènes les plus fréquemment mutés sont les gènes RPL5, RPL11 et RPS19 (37% des patients). Plus rarement, l’ABD est la conséquence de mutations dans le gène TSR2 ou dans le gène GATA-1. Ce dernier code pour un facteur de transcription majeur de l’érythropoïèse. Chez les patients ABD, les mutations de GATA-1 induisent une perte quasi-totale de la forme longue de GATA-1 qui est nécessaire à la différenciation de la cellule érythroïde. Notre groupe a identifié deux phénotypes de l’ABD in vitro en fonction du gène muté. En cas d’haploinsuffisance RPS19, la prolifération érythroïde est moins réduite qu’en cas d’haploinsuffisance RPL5 ou de RPL11. Une haploinsuffisance RPS19 n’altère pas la différenciation érythroïde et n’induit pas d’apoptose contrairement à l’haploinsuffisance RPL5 ou RPL11 où il existe un retard de différenciation érythroïde et un excès net d’apoptose responsable au moins en partie de la diminution drastique de la prolifération érythroïde dans ces phénotypes.HSP70 est impliquée dans la survie cellulaire et la différenciation érythroïde en protégeant GATA-1 du clivage par la caspase-3, une protéase activée lors de la différenciation érythroïde terminale. Comme la différence entre les deux phénotypes d’ABD in vitro concernait la différenciation érythroïde et la survie cellulaire, nous avons émis l’hypothèse selon laquelle la mutation de certains gènes RP provoque un défaut d’expression d’HSP70 conduisant au blocage de la différenciation érythroïde et à l’excès d’apoptose retrouvés dans les phénotypes sévères d’ABD.Nous avons étudié différents patients atteints d’ABD, porteurs de mutations dans les gènes RPS19, RPL5 ou RPL11 et généré un modèle in vitro d’ABD en exprimant, dans des cellules CD34+ humaines issues de sang de cordon, des ARN interférents ciblant RPL5, RPL11 ou RPS19. Chez les patients comme dans le modèle reproduisant l’ABD, l’haploinsuffisance RPL5 ou RPL11 diminue drastiquement l’expression protéique de HSP70 et de GATA-1 (Western blot, microscopie confocale et en cytométrie couplée à des techniques d’imagerie, (technologie ImageStream) à la différence de 1’haploinsuffisance RPS19. Dans tous les cas, HSP70 est normalement transcrite et traduite. Les inhibiteurs du protéasome (MG132, lactacystine, bortezomib) restaurent l’expression10de HSP70. La diminution d’expression de HSP70 est donc liée à une dégradation protéasomale. L’invalidation de RPL11 induit une polyubiquitinylation importante de HSP70. La transduction lentivirale de l’ADN complémentaire d’HSP70 dans les cellules primitives invalidées pour RPL11 permet de restaurer l’expression de HSP70 et de GATA-1 à un niveau similaire aux contrôles et de rétablir la prolifération cellulaire et la différenciation érythroïde, confirmant le rôle clé de HSP70 dans le phénotype sévère RPL5+/Mut ou RPL11+/Mut. Les formes les plus sévères de l’ABD sont associées à la dégradation de HSP70 par le protéasome. La perte de la protéine chaperone de GATA-1 induit la perte de GATA-1, facteur de transcription majeur de la différenciation érythroïde. Une augmentation de l’expression de HSP70 pourrait ainsi constituer une nouvelle approche thérapeutique dans l’ABD<br>Diamond-Blackfan anemia (DBA) is the first ribosomopathy identified and is characterized by a moderate to severe, usually macrocytic aregenerative anemia associated with congenital malformations in 50% of the DBA cases. This congenital rare erythroblastopenia is due to a blockade in erythroid differentiation between the BFU-e and CFU-e stages. The link between a haploinsufficiency in a ribosomal protein (RP) gene that now encompass 15 different RP genes and the erythroid defect is still to be fully defined. Recently, mutations in TSR2 and GATA-1 genes have been identified in a few DBA families. The GATA-1 gene encodes for the major transcription factor critical for erythropoiesis and mutation in this gene that lead to loss of expression of the long form of the protein, necessary for the erythroid differentiation accounts for erythroblastopenia of DBA phenotype. Our group and others (Dutt et al., Blood 2011) have shown previously that p53 plays an important role in the DBA erythroblastopenia, inducing cell cycle arrest in G0/G1 and depending on the nature of RP gene mutation, a delayed erythroid differentiation and an increased apoptosis. Indeed, we identified two distinct DBA phenotypes (H. Moniz, M. Gastou, Cell Death Dis, 2012): a haploinsufficiency in RPL5 or RPL11 reduced dramatically the erythroid proliferation, delayed the erythroid differentiation, and markedly increased apoptosis, while RPS19 haploinsufficiency while reduced the extent of erythroid proliferation without inducing significant apoptosis. While p53 pathway has been found to be activated in RP haploinsufficient erythroid cells in DBA patients or shRNA-RPS19, -RPL5, or -RPL11 infected CD34+ erythroid cells, the intensity of the p53 activation pathway (p21, BAX, NOXA) is different depending on the mutated RP gene. Since the differences between the two phenotypes involved the eytrhoid differentiation and the degree of apoptosis we hypothesized that HSP70, a chaperone protein of GATA-1 may play a key role in the erythroid defect of DBA. Indeed, HSP70 protects GATA-1 from the cleavage by the caspase 3, a protease activated during erythroid differentiation. As such reduced levels of HSP70 related to a RP haploinsufficiency could account for increased apoptosis and delayed erythroid differentiation of erythroid cells in DBA. Indeed, a defect in RPL5 or RPL11 decreased dramatically the expression level of HSP70 and GATA-1 in primary human erythroid cells from DBA patients and following in vitro knockdown of the proteins in CD34+ cells by RPL5 or RPL11 shRNA. Importantly, RPS19 haploinsufficiency did not exhibit this effect in conjunction with normal levels of HSP70 expression. Furthermore, we found that the decreased expression level of12HSP70 was independent on the p53 activation. Strikingly, HSP70 was noted to be degraded by the proteasome since the bortezomib, the MG132, or the lactacystin were able to restore both the HSP70 expression level and intracellular localization in the cell. The lentiviral infection of depleted RPL11 cord blood CD34+ cells with a wild type HSP70 cDNA restored both the erythroid proliferation and differentiation, and reduced apoptosis, confirming a critical role for HSP70 in the erythroid defect in the RPL11+/Mut DBA phenotypes. The loss of HSP70 may explain the loss of GATA-1 in DBA and also the erythroid tropism of the DBA disease. Restoration of the HSP70 expression level may be a viable and novel therapeutic option for management of this debilitating and difficult to manage erythroid disorder
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Matsson, Hans. "Studies of the Ribosomal Protein S19 in Erythropoiesis." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4283.
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Taylor, Allison. "Ribosomal Protein Mutations in Hematopoiesis and Zebrafish Development." Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10238.
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The focus of this thesis is the role of ribosomal proteins in hematopoiesis and development. Ribosomal proteins are mutated in patients with Diamond Blackfan anemia (DBA). These mutations primarily affect blood tissues, as DBA patients have a macrocytic anemia. We have identified hematopoietic defects in zebrafish with a mutation in ribosomal protein S29 (rps29). \(Rps29^{-/-}\) embryos have defects in hematopoietic stem cell formation, aorta specification, and hemoglobinization. Embryos also have increased numbers of apoptotic cells, and microarray analysis reveals up-regulation of a p53 gene signature. All of the hematopoietic phenotypes are rescued by p53 mutation, demonstrating that p53 activation induced by ribosomal protein knockdown is mediating the \(rps29^{-/-}\) mutant phenotype. In addition, polysome profiles of mutant embryos identify a decrease in 80s monosome and polysome fractions. Preliminary RNA sequencing analysis of the polysome fractions suggested a shift in genes being translated in the mutant. We performed a chemical screen on rps29 embryos. Using embryo morphology and vascular expression patterns as read-outs, 600 compounds of known bioactivity were screened. One compound, A-3, improves embryo morphology, and a structurally related compound, W-7, rescues the vasculature defect. These compounds are calmodulin inhibitors, and A-3 can also rescue the hemoglobin defect in \(rps29^{-/-}\) embryos. To elucidate the compounds’ mechanism of action, A549 and \(CD34^+\) cells with RPS19 knocked down by shRNA were treated with chemical hits. In these cells, calmodulin inhibitors cause a decrease of p21 even with p53 induction. These data support a model where calmodulin inhibition can inhibit the p53 pathway upon ribosomal protein knockdown. In parallel to our zebrafish studies, we generated induced pluripotent stem (iPS) cells from DBA patient fibroblasts as a part of a large-scale collaboration. Three iPS lines are validated, and a total of 27 lines will be generated from patients with mutations in RPS19, RPL5, and RPL11. Testing for defects in blood differentiation and determining the role of p53 in these lines will enable validation of this system as a model of DBA. The iPS lines can subsequently be used for chemical and genetic screening to identify novel DBA pathways and potential therapies.
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Favier, Philippe. "Maladie de blackfan-diamond avec malformations congenitales et anomalie chromosomique : a propos d'un cas." Aix-Marseille 2, 1988. http://www.theses.fr/1988AIX20302.
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Rio, Sarah. "Etude des métabolismes du fer et de l’hème au cours de l’érythropoïèse normale et pathologique (anémie de Blackfan-Diamond)." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB055/document.
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L’anémie de Blackfan-Diamond (ABD) est une maladie hématologique rare qui touche 4 à 7 individus/ million de naissances. Cette maladie se manifeste par une érythroblastopénie congénitale sévère (≤ 5% de précurseurs érythroïdes dans la moelle osseuse). L’anémie est arégénérative et souvent macrocytaire et associée à des malformations osseuses dans 40% des cas. 70% des patients sont porteurs d’une mutation hétérozygote pour un gène de protéine ribosomique impliquée dans la traduction cellulaire. Les gènes les plus fréquemment mutés sont les gènes RPS19 (25%), RPL11 (5%) et RPL5 (7%). La maladie est hétérogène et évolutive. Les liens entre la traduction cellulaire et l’érythropoïèse ne sont pas bien élucidés. Les objectifs de cette thèse ont été d’étudier les métabolismes de l’hème et du fer ainsi que l’expression des globines dans des cellules de patients atteints d'ABD et dans un modèle shARN ciblant l'expression de ces trois gènes afin de comprendre les causes du tropisme érythroïde de la maladie. Ce travail de recherche a permis de mettre en évidence un défaut majeur de synthèse des globines ayant pour conséquence une augmentation de la quantité d’hème libre et une production de formes réactives de l'oxygène toxiques dans les cellules des patients qui pourraient expliquer en partie l’apoptose cellulaire et le déficit de globules rouges. Alors que le métabolisme du fer ne semblait pas altéré dans l'ABD, l’étude de l’expression de différentes protéines importantes pour l’érythropoïèse au cours de la différenciation érythroïde in vitro dans des conditions contrôles et chez des patients a permis de confirmer et de caractériser le retard de différenciation cellulaire en cas de mutation des gènes RPL5 et RPL11. Ce travail montre que le retard de différenciation et le défaut d'hémoglobinisation mis en évidence s'expliquent par un déficit du facteur de transcription GATA-1 qui est primordial au cours de l'érythropoïèse. Ce déficit de GATA-1 dans des cellules déficitaires en RPL11 est dû à une dégradation de sa protéine chaperonne HSP70. La restauration de HSP70, permet d'augmenter l'expression de GATA-1 et d'améliorer la différenciation érythroïde et l'hémoglobinisation cellulaire pour le gène RPL11. Ces résultats permettent de mieux comprendre le tropisme érythroïde de l'ABD et de proposer HSP70 comme une cible thérapeutique prometteuse dans son traitement<br>Diamond-Blackfan anemia (DBA) is a rare hematologic disease that affects 4 to 7 individuals / million births. This disease is characterized by a severe congenital erythroblastopenia (less than 5% erythroid precursors in the bone marrow). Anemia is agerenative, often macrocytic and associated with bone malformations in 40% of cases. 70% of patients carry a heterozygous mutation for a ribosomal protein gene involved in cell translation. The most frequently mutated genes are RPS19 (25%), RPL11 (5%) and RPL5 (7%) genes. The disease is heterogeneous and can evolve. The link between cell translation and erythropoiesis is not well understood. The objectives of this thesis were to study haem and iron metabolisms as well as the expression of globins in DBA patients cells and CD34+ cells transduced with shRNA targeting the expression of these three genes in order to understand the causes of the erythroid tropism of the disease. This research has highlighted a major defect of globin synthesis resulting in an increase in the amount of free heme and a production of toxic ROS in patients' cells that could explain in part cell apoptosis and red blood cell deficiency. While iron metabolism did not appear to be altered in DBA, the study of the expression of various important proteins for erythropoiesis in normal CD34+ or DBA cells during erythroid differentiation in vitro confirmed a strong cell differentiation delay for RPL5 and RPL11 mutations. This work shows that the delay of differentiation and the lack of hemoglobinization can be explained by a deficiency of the transcription factor GATA-1, which is essential during erythropoiesis. This deficiency of GATA-1 in shRPL11 cells is due to a degradation of its chaperone protein HSP70. The restoration of HSP70 increases the expression of GATA-1 and improves erythroid differentiation and cellular hemoglobinization for the shRPL11 condition. These results provide a better understanding of the erythroid tropism of ABD and suggest a role for HSP70 as a promising therapeutic target in its treatment
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Skeppner, Gunnar. "Pure red cell aplasia in Swedish children : clinical features, epidemiological and etiological aspects of transient erythroblastopenia of childhood and of Diamond-Blackfan anemia /." Örebro ; Stockholm, 2002. http://diss.kib.ki.se/2002/91-628-5092-x/.
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Da, Costa Lydie. "Rôle de la protéine ribosomique S19 dans l'érythropoïèse : implications dans la physiopathologie de l'anémie de Diamond-Blackfan." Paris 7, 2004. http://www.theses.fr/2004PA077045.
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Macri, Serena. "Diamond-Blackfan anemia: Immunophenotypic profiling of erythroid progenitor-derived extracellular vesicles and analysis of new candidate genes." Doctoral thesis, Università del Piemonte Orientale, 2017. http://hdl.handle.net/11579/102646.
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Moniz, Hélène Soledade. "Etude de la prolifération et de la différenciation érythroïde in vitro et de la potentielle implication de la voie de p53 au cours de l'anémie de Blackfan-Diamond (ABD)." Paris 7, 2011. http://www.theses.fr/2011PA077124.
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L'anémie de Blackfan-Diamond (ABD) est une érythroblastopénie congénitale rare. Le phénotype et le génotype des patients sont hétérogènes. 40% des patients ont des malformations congénitales et 50% sont porteurs d'une mutation dans un gène d'une protéine ribosomique (PR), principalement RPS19 (25%), RPL5 (7%) et RPL11 (5%). Il en résulte un défaut de maturation des ARNr. Cependant, les mécanismes qui expliquent les liens particuliers entre les anomalies de la biogenèse des ribosomes et de l'érythropoïèse restent obscurs. Des modèles animaux reproduisant la maladie ont montré une activation de p53. L'activation de la voie p53 après génération d'un stress nucléolaire due au défaut de maturation des ARNr pourrait être responsable de l'érythroblastopénie, caractéristique de l'ABD. Pour vérifier cette hypothèse, nous avons étudié au cours de la différenciation érythroïde terminale, la prolifération, la différenciation érythroïde, le niveau d'apoptose, le cycle cellulaire et la voie p53, dans des cellules CD34+ issues de patients et dans des CD34 de sang de cordons infectées par des lentivirus inhibant spécifiquement l'expression de RPS19, RPL5 ou RPL11. Nous montrons qu'il existe différents niveaux d'activation de la p53 selon la PR invalidée et qu'une haploinsuffisance en RPS19 s'accompagne d'une prolifération érythroïde diminuée, une différenciation érythroïde normale et peu ou pas d'apoptose tandis qu'une haploinsuffisance en RPL5 et RPL11 conduit à une diminution drastique de la prolifération et un retard de différenciation érythroïde avec un excès d'apoptose. Dans tous les cas, on note un arrêt du cycle cellulaire en phase Go/Gl. Nous confirmons ainsi le postulat initial<br>Diamond-Blackfan anemia (DBA) is a rare congenital erythroblastopenia, characterized by an aregenerative anemia. The DBA phenotype and genotype is heterogeneous: 40% of DBA cases have various congenital malformations and 50% of the patients carry a mutation in a ribosomal protein (RP) gene, mostly RPS19 (25%), RPL5 (7%), RPL11 (5%). This RP gene mutation leads to a defect in the rRNA maturation. However, the exact mechanisms that explain the special link between the defects in the ribosome biogenesis and in erythropoiesis are still to be defined. Animal models reproducing the disease exhibited a p53 activation pathway. Activation of p53 after generation of a nucleolar stress due to the defect in rRNA could explain the erythroblastopenia, the main characteristic of DBA. To verify this hypothesis, we studied the erythroid prolifération and differentiation, the degree of apoptosis, the cell cycle and the p53 pathway, either in CD34+ cells from DBA patients or in CD34+ cells from cord blood infected with specific shRNA against RPS19, RPL5 and RPL11. We found différent levels of p53 activation depending of the RP. Haploinsufficiency in RPS19 leads to a decreased erythroid proliferation, a normal erythroid differentiation and no apoptosis. By contrast, haploinsuffïciency in RPL5 or RPL11 leads to a dramatic decreased in erythroid proliferation and a delayed in differentiation, with an important activation of apoptosis. In any case, we observed a cell cycle arrest in Go/Gl phase. Thus, after p53 activation, cell cycle arrest after RPS19, RPL5 or RPL11 inhibition and cell cycle arrest and activation of apoptosis after RPL5 or RPL11 inhibition may explain DBA erythroblastopenia
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Ludwig, Leif [Verfasser]. "Altered Translation of GATA1 in Diamond-Blackfan Anemia and the Role of Cyclin D3 in Erythropoiesis / Leif Ludwig." Berlin : Freie Universität Berlin, 2015. http://d-nb.info/1075757630/34.
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Ludwig, Leif Si-Hun [Verfasser]. "Altered Translation of GATA1 in Diamond-Blackfan Anemia and the Role of Cyclin D3 in Erythropoiesis / Leif Ludwig." Berlin : Freie Universität Berlin, 2015. http://nbn-resolving.de/urn:nbn:de:kobv:188-fudissthesis000000099928-1.
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Aguissa, Toure Almass-Houd. "Bases moléculaires de l'anémie de Diamond-Blackfan : étude structure-fonction de la protéine ribosomique RPS19 chez Saccharomyces cerevisiae." Toulouse 3, 2008. http://thesesups.ups-tlse.fr/427/.
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L'anémie de Diamond-Blackfan (ADB) est une érythroblastopénie congénitale rare associée à des mutations mono-alléliques dans plusieurs gènes de protéine ribosomique. Cette liaison suggère une relation causale entre l'altération de la biogenèse ou de la fonction des ribosomes et cette pathologie. Le gène RPS19 est le plus fréquement muté (25% des patients). Pour comprendre l'impact des mutations, en particulier les mutations ponctuelles faux-sens, nous avons engagé une étude structure-fonction de l'homologue de la protéine RPS19 chez la levure Saccharomyces cerevisiae. Parallèlement, nous avons mené un travail collaboratif pour déterminer la structure cristalline de l'homologue de RPS19 de l'archeae Pyrococcus abyssi. Nos résultats distinguent deux types de mutations : certaines, enfouies dans la structure, affectent le repliement et la stabilité de la protéine, tandis que d'autres, en surface de la protéine, inhibent l'incorporation de RPS19 dans les particules pré-ribosomiques 40S. Par ailleurs, nous avons déterminé la séquence de localisation nucléaire et les déterminants moléculaires de l'adressage nucléaire de RPS19. Les différentes mutations de RPS19 n'interfèrent pas avec ce mécanisme de transport. Ainsi, les mutations faux-sens de la protéine RPS19 affectent en premier lieu la capacité de la protéine à être incorporée dans les pré-ribosomes, ce qui altère la biogenèse des ribosomes. Ceci pourrait d'une part activer une réponse de stress et d'autre part conduire à un déficit en ribosomes, deux facteurs qui pourraient être fatals dans certains processus physiologiques comme l'érythropoïèse. Ce mécanisme peut être étendu à toute protéine ribosomique mutée dans l'ADB<br>Diamond-Blackfan Anaemia (DBA) is a rare congenital erythroblastopenia associated with mono-allelic mutations in several ribosomal protein genes. This linkage suggests a causal relationship between alteration of ribosome biogenesis or functions and this pathology. ?The RPS19 gene is the most frequently mutated (25% of patients). To understand the impact of the mutations, especially missense mutations, we undertook a structure-function study of RPS19 homolog in yeast Saccharomyces cerevisiae and we conducted a collaborative work to determine the crystal structure of archeae Pyrococcus abyssi RPS19. Our results distinguish two types of mutations: some affect residues buried in the structure and alter the protein folding and stability, while others change amino acids at the protein surface and prevent incorporation of RPS19 into 40S pre-ribosomal particles. In addition, we determined the nuclear localization sequence and the molecular determinants of RPS19 transport to the nucleus. Mutations linked to DBA do not interfere with the nuclear localization of the protein. Thus, missense mutations in RPS19 primarily affect the ability of the protein to be incorporated into pre-ribosomes, which alters ribosome biogenesis. This could on the one hand activate a stress response and on the other hand lead to ribosome shortage, two events that could be fatal to some physiological processes like erythropoiesis. A similar mechanism can be proposed for any ribosomal protein mutated to the DBA
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GISMONDI, ANGELO. "Deficiency of ribosomal protein S19 (RPS19) causes the reduction of translation elongation and rRNA production." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/202289.
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La biogenesi ribosomali è un processo la cui regolazione è in accordo alla crescita cellulare. Si ritiene, infatti, che la sintesi dell’rRNA e delle proteine ribosomali sia finemente controllata da meccanismi mirati a coordinarla, così da evitare alla cellula inutili sprechi di energia. Per studiare questi meccanismi abbiamo alterato il naturale processo di produzione dei ribosomi down-regolando la sintesi della proteina strutturale della subunità piccola del ribosoma S19 (RPS19), nella linea cellulare leucemia mieloide delle K562C, tramite un sistema di interference specifico. Cellule private di RPS19 mostravano una diminuzione dei livelli delle altre proteine ribosomali apparteneti sempre alla subunità minore del ribosoma (RPS), mentre non presentavano modulazioni rilevabili sulla quantità delle proteine costituenti la subunità grande dello stesso (RPL). Come conseguenza è stato possibile osservare un accumulo della subunità 60S e un arresto della proliferazione e della crescita cellulare. È stato osservato che la diminuzione delle RPS non dipendeva da una regolazione trascrizionale dei loro messaggeri e che nessuna RP esisteva in forma libera nel citoplasma delle cellule interferate per RPS19. Sorprendentemente, la deficienza di RPS19 induceva il reclutamento di tutti i messaggeri delle RP sui polisomi, suggerendo un aumento della loro attività traduzionale. Lo stesso fenomeno è stato osservato in altre linee cellulari (TF-1C e PC3), anche in seguito a interference di altre proteine ribosomali (RPS6 e RPL11). Ulteriori analisi hanno mostrato che il caricamento sui polisomi dei RP mRNA indotto dall’interference di RPS19 era parzialmente bloccato da trattamento con inibitori della proteina mTOR (mammalian target of rapamycin), quali rapamicina e wortmannina. L’osservazione di un’associazione con i polisomi dei messaggeri delle RP era però in antitesi con l’osservazione di una diminuita quantità di RPS, così per cercare una spiegazione a tale fenomeno abbiamo studiato la stabilità delle proteine ribosomali in cellule interferate per RPS19. Il trattamento con l’inibitore del proteasoma ha mostrato che non c’era aumento di degradazione proteica indotta dall’interference. L’analisi della misurazione del tasso di allungamento di traduzione ha indicato, invece, che la carenza di RPS19 causava nelle cellule un rallentamento dell’attività dei ribosomi. Dunque, l’osservato aumento di associazione dei RP mRNA con i polisomi potrebbe essere spiegato come un’alterazione del rapporto tra inizio ed allungamento della traduzione e potrebbe non voler indicare un aumento della sintesi di proteine ribosomali. La conseguenza della riduzione di RPS19 consisterebbe in una riduzione della sintesi proteica globale dovuta probabilmente a una diminuzione del tasso di allungamento. Inoltre, il turn-over delle RPS potrebbe essere maggiore di quello delle RPL tanto da provocare uno sbilanciamento delle subunità del ribosoma. D’altra parte, in cellule K562C e TF-1C la diminuzione di RPS19 causava la riduzione dei livelli del precursore degli rRNA maturi, il 47S, ma non ne modifica la stabilità. In ultima analisi, linee cellulari linfoblastoidi di pazienti affetti da anemia di Diamond Blackfan, caratterizzati da mutazioni in geni di proteine ribosomali, presentavano la stessa diminuzione dei livelli di 47S osservati nelle linee cellulari interferate per RPS19 da noi analizzate.<br>Ribosome biogenesis is a process regulated according to cell growth. The synthesis of rRNAs and ribosomal proteins (RP) are thought to be controlled by mechanisms aimed to coordinate them thus avoiding unnecessary waste of energy. To study these mechanisms we altered the production of RPS19 in the erythroleukemia cell line K562 by siRNA-mediated down regulation. RPS19-depleted cells showed a decrease of the other RPs of the small ribosomal subunit (RPS), but not of the RP of the large subunit (RPL). As a consequence an accumulation of 60S subunits was observed in RPS19 deficient cells. The decline in RPS level was not due to transcriptional regulation and free cytoplasmic RP were not detected. Unexpectedly, RPS19 deficiency caused a recruitment of all RP mRNAs on polysomes suggesting an increase in translational activity. The same phenomenon was observed in other cell lines (TF-1 and PC3) and after depletion of other RPs (RPS6 and RPL11). Further analysis showed that the polysomal recruitment of RP mRNA induced by RPS19 deficiency was partially inhibited by mammalian target of rapamycin (mTOR) inhibitors rapamycin and wortmannin. To understand how an increase in polysome-associated RP mRNA resulted in the observed decrease of the level of RPSs, we measured the stability of the proteins. The administration of proteasome inhibitor showed that there was not an increase in protein degradation caused by RPS19 deficiency. Finally, the measurement of general elongation rate indicated that the depletion of RPS19 induces a slowing down of ribosome transit time. Therefore the observed increase in RP mRNA polysomal association may be due to the alteration of the ratio initiation/elongation and would not result in an increase of RP synthesis. So, the consequence of RPS19 reduction is a general decrease of RP level due, possibly, to a decline of the elongation rate. In addition, RPS turnover may increase with respect to RPL causing a ribosomal subunit unbalance. On the other hand, in K562C and TF-1C cells, RPS19 depletion causes the reduction of the 47S rRNA production but it does not alter its stability. Finally, also Diamond Blackfan anemia (DBA) lymphoblastoid cell lines, characterized by ribosomal protein mutations, presented the decrease of the rRNA precursor as we found in our cells.
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Anton, Aurore. "Identification et caractérisation de gènes candidats pour la découverte de nouveaux mécanismes physiopathologiques à l'origine de l'anémie de Blackfan-Diamond." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30267.
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Des mutations dans les gènes codant les protéines impliquées dans la biogenèse des ribosomes provoquent des maladies spécifiques chez l'homme, les ribosomopathies. L'une d'entre elles, l'Anémie de Blackfan-Diamond (ABD) se caractérise par une perte importante de cellules érythroïdes dans la moelle osseuse qui entraîne une anémie sévère et dans certains cas d'autres anomalies comme des malformations cranio-faciales. Bien que les mutations soient connues pour une vingtaine de gènes représentant environ 3/4 des patients atteints d'ABD, l'identification des gènes mutés dans les cas restants présente un enjeu majeur afin d'améliorer le diagnostic de la maladie et de découvrir de nouvelles cibles thérapeutiques. Le but de ma thèse a été de générer des modèles d'ABD chez le poisson-zèbre en utilisant la technique d'édition du génome CRISPR/Cas9 sur la base de nouveaux gènes candidats récemment identifiés par séquençage d'exomes chez les patients ABD Français. Mes résultats montrent que seuls les embryons homozygotes mutants pour l'un des gènes développent des phénotypes en lien avec l'ABD: une anémie sévère associée à des défauts généraux de développement comme un retard de croissance, une microcéphalie et l'absence de mâchoire. Quant aux deux autres gènes, bien que les embryons homozygotes mutants présentent des phénotypes développementaux, les résultats n'ont pas mis en évidence de défauts en lien avec la pathologie. Les mécanismes moléculaires à l'origine des symptômes observés chez les patients restent néanmoins à être caractérisés. La littérature et mes résultats montrent que les modèles intégrés actuels de l'ABD, ne reproduisent pas fidèlement la situation observée chez les patients. En effet, chez le poisson-zèbre les mutants dans les gènes ABD développent des phénotypes qui ne se limitent pas aux tissus affectés dans la pathologie humaine. Cela peut s'expliquer par le fait que chez l'homme les gènes responsables de l'ABD sont haploinsuffisants, alors que chez le poisson-zèbre, ils ont un comportement Mendélien récessif. Ainsi, parallèlement à mon travail de validation de nouveaux gènes de l'ABD, j'ai développé un système intégré vertébré modélisant l'ABD sur la base d'un gène causal préalablement identifié: TSR2 (20S rRNA maturation factor). Ce gène est localisé sur le chromosome X et la mutation faux-sens identifiée chez les patients se comporte comme un allèle récessif puisque seulement des patients garçons sont affectés. Cette particularité fait de ce gène un candidat idéal pour générer un modèle animal reflétant au mieux la génétique des patients ABD. J'ai généré une lignée mutante chez le poisson-zèbre, pour laquelle les embryons homozygotes mutants développent spécifiquement des défauts observés chez les patients: une anémie tardive ainsi que des défauts de mise en place des os de la mâchoire. [...]<br>Mutations in genes encoding proteins involved in ribosome biogenesis cause specific diseases in humans, called ribosomopathies. One of these, Diamond-Blackfan Anaemia (DBA), is characterized by a significant loss of erythroid cells in the bone marrow leading to severe anaemia and in some cases other abnormalities such as cranio-facial malformations. Until now, mutations are known for about 20 genes representing about 3/4 of patients with DBA, identifying the mutated genes in the remaining cases presents a major challenge in order to improve the diagnosis of the disease and discover new therapeutic targets. The aim of my thesis was to generate DBA models in zebrafish using the CRISPR/Cas9 genome editing technique on the basis of new candidate genes recently identified by exome sequencing in French DBA patients. My results show that homozygous embryos mutant for only one of these genes develop phenotypes that begin to resemble DBA, including severe anaemia associated with general developmental defects including growth retardation, microcephaly and lack of jaw; for the other two genes homozygous mutant embryos show developmental phenotypes unrelated to the pathology. The molecular mechanisms at the origin of the symptoms observed in the patients remain to be completely understood. The literature and my results show that the current integrated models of DBA do not satifyingly reproduce the physiopathology of patients. Indeed, in zebrafish, mutants in the DBA genes develop phenotypes that are not limited to the tissues affected in human pathology. This can be explained by the fact that in humans the genes responsible for DBA are haploinsufficient, whereas in zebrafish they have a recessive Mendelian behaviour. Thus, in parallel with my work to validate new DBA genes, I have established an integrated vertebrate model based on a previously identified causal gene: TSR2 (20S rRNA maturation factor). This gene is localized on the X chromosome and the missense mutation identified in patients behaves as a recessive allele since only male patients are affected. This particularity allows this gene to be an ideal candidate to generate an animal model that best reflects the genetics of DBA patients. I generated a tsr2 mutant in which the homozygous mutant embryos develop defects observed in patients: late anaemia and jaw bone placement defects. We also observed that, as described in DBA patients, adult heterozygous fish mutant for tsr2 are predisposed to developing cancers. This model could not only be used to understand how the dysfunction of a ubiquitous process such as ribosome biogenesis leads to specific defects, but also to explain the paradox of the transition from a hypo-proliferative state with phenotypes of bone marrow failure and anaemia, to a hyper-proliferative state leading to high cancer risks later in life. In the future, this model may improve the diagnosis of patients and lead to the emergence of new therapeutic targets by offering the possibility of performing pharmacological screening for the development of new treatments