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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Shela koma na mizimu mema - remembering our ancestors

Mahazi, Jasmin Anna-Karima January 2010 (has links)
Vave is generally defined as a corpus of agricultural songs as they are sung and performed by Bajuni farmers - an ethnic subgroup of the Swahili - on the eve of burning the bush, a stage of slash and burn cultivation. Although the song’s main theme is agriculture and each cultivation step in particular is given attention, an analysis of the aesthetics of Vave from the viewpoint of oral literature unearths the secret and sacred dimension of Vave performance. Death, bereavement, resurrection, and spirituality are, besides agricultural cultivation, the basic aspects of the Vave. Indeed the Vave performance may be more correctly recognised as an ancient religious rite which has ancestral worship as a central issue. Although the worship of ancestors is irreconcilable with the Islamic belief system, Vave is still performed by the Muslim Bajuni farmers today. This essay attempts to outline in which way the ancestors are annually remembered, revived or actualised in the present by Bajuni farmers through the performance of an oral tradition.
42

Full Moon Soup

Yerington, Hannah L. 24 May 2022 (has links)
No description available.
43

African spirituality set in a context of Batswana Christians

Segami, Tom Mogorogi 11 1900 (has links)
In transmitting the Gospel, Western missionaries passed on their portrayal of Christ as a European. Conversion to Christianity was aimed more at promoting Western cultural, moral and spiritual issues. Western culture has thus been an obstacle or hindrance to effective cross-cultural communication of the Christian message. Batswana believers are challenged to peel the Western cultural layers off Christianity, in order to reclaim Christ. Batswana Christians will have to dress Christianity in the Tswana cultural heritage if it is to be of any lasting significance to them. Christian spirituality is centred on Jesus Christ, in the worldview of all Christians. Jesus joins faith and culture together. If Christianity is truly universal, then every culture should surrender to Jesus Christ and not to any other culture. Jesus’ question “who do you say that I am?” (Mk 8: 29), challenges Batswana Christians to write their own fifth Gospel. / Christian Spirituality Church History & Missiology / Thesis (M. Th. (Christian Spirituality))
44

The sacrifice of the mass and the concept of sacrifice among the Xhosa : towards an inculturated understanding of the eucharist

Sipuka, Sithembele 11 1900 (has links)
The last Supper Jesus had with his disciples on the night before he died on the cross is the foundation of a major liturgical celebration in the Catholic Church called 'the Eucharist'. One of the major designations of the Eucharist is that it is a sacrifice. The starting point of this work is that the sacrificial character of the Eucharist is not as meaningful and relevant for Xhosa people as it should be. The way forward is to study the Eucharistic and Xhosa sacrifices, compare them and suggest ways of rendering the Eucharistic sacrifice meaningful and relevant to Xhosa the people. Although not conclusive, the New Testament gives a strong foundation for the sacrificial understanding of the Eucharist. The Eucharist, as interpreted through the Last Supper accounts, covers all the conventional intentions of sacrifice, i.e. propitiation, communion, thanksgiving and mutual responsibility. The Fathers of the Church affirm the sacrificial character of the Eucharist with varying emphases, but taken together, their understanding shows development of thought and complementarity of themes. In the Middle Ages the most pronounced intention of the . Eucharistic sacrifice is propitiation and post Tridentine theological reflection is informed by this mentality. According to modem and contemporary thought, Christ's death on the cross, which is sacrarnentally represented in the Eucharist, is not an act performed on our behalf to appease an angry God but God's act of love towards us. The emphasis is on self-offering to God as exemplified by Christ. The Xhosa people still have regard for sacrificial rituals, but modernity has modified and sometimes changed their understanding and practice of sacrifice. The principle of God's universal salvific will and the doctrine of incarnation provide theological grounds for inculturating the Eucharist. Thus the inclusion of ancestors and use of cultural symbols in the celebration of the Eucharist may render it meaningful to Xhosa people. Relating the Eucharist to Xhosa culture will revitalise the communion element in Eucharistic sacrifice, which element has been lost sight of through the centuries. Eucharistic sacrifice in its turn will help Xhosa Catholics to have a deepened understanding of sacrifice that extends beyond performance of rituals to include self-giving. / Philosophy, Practical & Systematic Theology / D.Th.(Systematic Theology)
45

IsiZulu traditional healers’ perspective of ukuhlonipha in context

Nene, Jabulani Owen 31 January 2014 (has links)
Traditional healers are one among professionals that are viewed as the most significant people in African Society. They are accorded the highest esteem because of the role they play in saving people’s lives and promoting cultural aspects such as ukuhlonipha amasiko in isiZulu. It should be remembered that this word ukuhlonipha which means to respect, is used across cultures to maintain peace within family and society. It all depends on which culture promotes it more than others. It is sociolinguistic truism that ukuhlonipha is essentially linked to the ubuntu philosophy of African people. However, traditional healers more than other people follow ukuhlonipha culture in numerous ways, especially when they meet, being consulted and during traditional ceremonies. They serve and promote what in IsiZulu is known as ukuhlonipha, which to the uninitiated and sometimes even to the scholars of this philosophy is a mystery. It is for this reason and others that people view them as the soul of society. This study looks at relevant sociolinguistic theories especially the politeness theory to analyze most of the hlonipha features shown by traditional healers, apprentice and people during consultation. / African Languages / M.A. (African Languages)
46

Indigenous Ceremony and Traditional Knowledge: Exploring their use as models for healing the impacts of traumatic experiences

Nyman, Sheila A. 21 January 2015 (has links)
Using Indigenous methodology and a story telling method this thesis is the result of research that looks at the benefits of traditional Indigenous ceremony and healing practices as a way to heal from traumatic experiences. A thematic analysis technique was employed to reveal four themes that emerged from the stories told by Indigenous Knowledge Keeper participants. The first theme is the importance of our connection to all living things including our own selves. Another is recognizing our greatest teachers nature and animals. Cleansing emerged at the center of all traditional healing strategies and the final theme encompasses all that we are as life on this planet spirit or energy. Trauma can be understood as any event that creates difficulty for the individual to cope whether the event that caused the experience was purposeful or accidental. While people do find amazing ways to cope with circumstances that are overwhelming, neurobiology tells us how trauma is processed and impacts the workings of the brain. Trauma in the nervous system can be understood as the result of a person or group or community’s inability to stay safe or to feel safe during the experiences. Indigenous people live with the ongoing effects of intergenerational trauma caused by colonization including the Indian Residential School experience, as well as ongoing systemic oppression. All traumas can activate the deeply held traumas that have been transmitted trans-generationally. In essence we carry intergenerational traumas. I believe that Indigenous people were practicing healing on a regular basis within their traditional ceremonies, dances and practices before contact and these practices may inform a model of health and wellness that could be useful in healing the effects of trauma that impacts Indigenous people today. Ceremonies and traditional teachings were shared communally before contact and are now being revived as we embrace the cultural practices of our ancestors across this land. Within our Indigenous ways of knowing we recognize that we are related to everything in creation we are connected and depend on one another. In 1884, under the Potlatch Law & section141 of the Indian Act our ceremonies, spiritual practices and traditional knowledges were made illegal; our people were imprisoned for practicing them (UBC First Nations Studies, 2009). Today we are in a state of desperation for healing strategies that work for who we are as a people. The Elders in this research shared how this can be done. / Graduate / 0452 / 0622 / 0347 / sheilanyman@shaw.ca
47

La racine des mots : héritage, langue et identité chez les apprenants du gaélique irlandais au Canada

Montpetit, Amélie 08 1900 (has links)
No description available.
48

Determinantes sociais de doen?as e agravos nas comunidades quilombolas de Feira de Santana-BA

Ara?jo, Roberta Lima Machado de Souza 10 March 2017 (has links)
Submitted by Jadson Francisco de Jesus SILVA (jadson@uefs.br) on 2018-05-03T21:47:11Z No. of bitstreams: 1 Disserta??o _Roberta.pdf: 3305166 bytes, checksum: a41670e5ec5d0826e0e9c965b8330933 (MD5) / Made available in DSpace on 2018-05-03T21:47:11Z (GMT). No. of bitstreams: 1 Disserta??o _Roberta.pdf: 3305166 bytes, checksum: a41670e5ec5d0826e0e9c965b8330933 (MD5) Previous issue date: 2017-03-10 / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / Studies relating to the investigation of the standards of life and health of Quilombola populations are still limited, especially regarding the analysis of the factors associated with the prevalence of injuries and diseases. Aims: Analyzing diseases and injuries which are more prevalent and verifying their association with socioeconomic, environmental factors and health patters in Quilombola communities in Feira de Santana, Bahia, in 2016. Materials and methods: this is a population-based prevalence study carried out with 864 adults quilombolas of both sexes, aged above 18 years, residents in two Quilombolas communities of Feira de Santana, Bahia. A probabilistic sample was used. The data were collected through home visits, having been applied three validated instruments, containing questions related to demographic, socio-economic standards, environmental, health patterns as well as diseases and injuries. Descriptive and bivariate analyses were carried out, whereas a IC80% and p ? 0,20 were considered to verify the association between the exposure and outcome variables. An exploratory factor analysis, from the use of the tetrachoric correlation, in order to identify which diseases and injuries represent the higher prevalence the most. In order to analyze the factors associated with diseases and injuries, it was used the hierarchical logistic regression analysis. Data were analyzed using the statistical package Stata Corportion College Station, United States (STATA), in version 12.0. As a result of this research findings, two scientific papers were written. The first one is a descriptive study, which aimed to trace the epidemiological profile of the living standards and health of Quilombola communities. To achieve the aims of this article, averages of the quantitative variables and absolute and relative frequencies of qualitative variables of each community were estimated as well as the prevalence of injuries and diseases. The second article is an exploratory study, which analysed the social determinants of disease and injuries in Quilombolas communities of Feira de Santana, Bahia. Through the exploratory factor analysis, latent factors were established. In addition, bivariate and multivariate analyses were carried out to test statistically significant association. Results: in the first article, it was found that Quilombola communities of Feira de Santana, Bahia have very similar demographic andsocioeconomic characteristics and both are vulnerable in theirlife and health standards. From 864 respondents, 63,0% were female, married, with an avarage of 42,6 years of age and an average of 7 years of schooling, as well as 73,4% have informal jobs, especially in the roles of farmer labors and agricultors. In relation to environmental vulnerability, it is pointed out that 99,5 percent have no sanitarian system. Among the data on health patterns, it was noted that 67,1% said that they rarely seek for health services. The most prevalent diseases were: Hypertension (22,3%); diseases of bones (15,8%); diseases of sspine (38,4%) parasitic diseases (25,0%). The most prevalent health aggravations were linked to mental health: anxiety (26,7%); phobias (12,3%) and mental disorders (18,4%). In the second article it was found that the factors which responded more to diseases and most prevalent injuriess were related to mental health diseases (48,8%), chronic diseases (39,2%) and diseases of bones and spine (50,0%). Factor 1: mental health injuries it was found that families who do not receive social benefits have 1,43 times higher chance of having some aggravation in mental health. Factor 2: chronic diseases, it was found that individuals who have little consumption of vegetables and fruits show to have possibility of 1,42 times higher chances to develop a chronic disease. Factor 3: diseases of the bones and spine. It was observed that the individuals who are working have 1,44 times greater chance of having bone and spine diseases. For those who receiving social benefits, that possibility raises to 1,93 times of chance to develop spine and bone diseases. The hierarchical logistic regression analysis was performed for the three factors (1-mental health harms, 2-chronic diseases and bone diseases and 3 column). Multivariate analysis on the associated factors of diseases and injuries in the Quilombola communities, with respect to the factor 1 were: receiving social benefits (HR=1,63 CI80%:1,07; 2,50); material used in the construction of the house (HR=3,22; CI80%:1,17; 8,80); disposal of the garbage (HR=1,51 CI80%:1,07; 2,13); have bathroom (HR=2,82; CI80%:1,17; 6,77); self-assessment of health (HR=2,64 CI80%:1,92; 3,65); type of medication: (HR=0,15; CI80%:0,05; 0,45); problems with cavities/canal (HR=1,47 CI80%:1,07; 2,01); age (HR=1,84; CI80%:1,19; 2,84) and sex (HR=0,48 CI80%:0,34; 0,67). In relation to the factor 2, were: material used in the construction of the house (HR=3,18; CI80%:1,09; 9,28); have bathroom (HR=3,69 CI80%:1,36; 10,01); age (HR=1,87; CI80%:1,18; 2,95) and sex (HR=0,47; IC80%:0,32; 0,68). For factor 3, the variables were: years of study (HR=1,77; CI80%:1,20; 2,62); self-assessment of health (HR=1,64; CI80%:1,15; 2,32); type of medication (HR=6,12; CI80%: 2,59; 14,4) and age (HR=1,61; CI80%:1,03; 2,51). Conclusions: scientific evidence was produced about the living standards and health of Quilombola communities of Feira de Santana, Bahia and of social determinants associated with diseases and injuries that reach these populations the most. Thus, it was found that diseases and injuries in Quilombola populations are determined by demographific, socioeconomic, environmental factors and health patterns. It is expected that the results of this study may support further research with this kind of population and that it may contribute to the implementation of specific health and social policies, as well as to carry out intersectoral interventions with loco-regional applicability. / Ainda s?o escassos os estudos referentes ? investiga??o da condi??o de vida e sa?de das popula??es quilombolas, especialmente no que tange ? an?lise dos fatores associados ? preval?ncia de doen?as e agravos. Objetivos: Analisar as doen?as e agravos mais prevalentes e verificar sua associa??o com fatores socioecon?micos, ambientais e das condi??es de sa?de nas comunidades quilombolas do munic?pio de Feira de Santana, Bahia, no ano de 2016. Materiais e M?todos: Trata-se de um estudo de preval?ncia, de base populacional, realizado com 864 adultos quilombolas, de ambos os sexos, com idade acima de 18 anos, residentes nas duas comunidades quilombolas de Feira de Santana, Bahia. Foi utilizada uma amostra probabil?stica. A coleta de dados foi realizada atrav?s de visitas domiciliares, tendo sido aplicados tr?s instrumentos validados, contendo perguntas referentes ?s condi??es demogr?ficas, socioecon?micas, ambientais, das condi??es de sa?de e acerca das doen?as e agravos. Foram feitas an?lises descritivas e bivariadas, considerando um IC80% e p?0,20 para verificar a associa??o entre as vari?veis de exposi??o e de desfecho. Realizou-se uma an?lise fatorial explorat?ria, a partir do emprego da correla??o tetrac?rica, com objetivo de identificar quais as doen?as e agravos mais prevalentes. Para analisar os fatores associados ?s doen?as e agravos, empregou-se a an?lise de regress?o log?stica hierarquizada. Os dados foram analisados utilizando-se o pacote estat?stico Stata Corportion Colege Station, Estados Unidos (STATA), em sua vers?o 12.0. A partir dos achados desta pesquisa, foram elaborados dois artigos cient?ficos. O primeiro artigo corresponde a um estudo descritivo, o qual visou tra?ar o perfil epidemiol?gico das condi??es de vida e sa?de das comunidades quilombolas. Para atingir os objetivos deste artigo, foram estimadas as m?dias das vari?veis quantitativas e as frequ?ncias absolutas e relativas das vari?veis qualitativas, de cada comunidade, assim como foram estimadas a preval?ncia das doen?as e agravos. O segundo artigo se constitui em um estudo explorat?rio, o qual analisou os fatores associados a doen?as e agravos nas comunidades quilombolas de Feira de Santana, Bahia. Mediante a an?lise fatorial explorat?ria, foram estabelecidos os fatores latentes. Al?m disso, foram realizadas an?lises bivariadas e multivariadas para verifica??o de associa??o estatisticamente significante. Resultados: No primeiro artigo, constatou-se que as comunidades quilombolas de Feira de Santana-BA possuem caracter?sticas demogr?ficas e socioecon?micas bem similares, sendo que as duas se encontram vulnerabilizadas em sua condi??o de vida e sa?de. Dos 864 entrevistados, 63,0% s?o do sexo feminino, casados, apresentando uma m?dia de idade de 42,6 anos, e de escolaridade, uma m?dia de 7 anos de estudo, bem como 73,4% realizam trabalhos informais, especialmente nas fun??es de lavrador e agricultor. Em rela??o ? vulnerabilidade ambiental, destaca-se que 99,5% n?o possuem rede de esgoto. Dentre os dados relativos ?s condi??es de sa?de, observou-se que 67,1% disseram raramente procurar os servi?os de sa?de. As doen?as de maior preval?ncia foram: doen?as de ossos (15,8%); hipertens?o arterial (22,3%); doen?as parasit?rias (25,0%); doen?as de coluna (38,4%). Os agravos em sa?de mais prevalentes ligados ? sa?de mental foram: fobias (12,3%); transtornos mentais comuns (18,4%) e ansiedade (26,7%). No segundo artigo verificou-se que, os fatores que mais respondiam ?s doen?as e agravos mais prevalentes estavam relacionados a doen?as cr?nicas (39,2%); agravos em sa?de mental (48,8%) e a doen?as de ossos e coluna (50,0%). Do fator 1: agravos em sa?de mental, verificou-se que fam?lias que n?o recebem benef?cios sociais t?m 43% mais chances de ter algum agravo em sa?de mental. Do fator 2: doen?as cr?nicas, constatou-se que os indiv?duos que fazem pouco consumo de verduras, frutas e legumes apresentam possibilidade de 1,42 mais chances de desenvolver uma doen?a cr?nica. Do fator 3: doen?as dos ossos e de coluna, averiguou-se que sujeitos que est?o trabalhando t?m 1,44 mais chances de ter doen?as de ossos e coluna, e para os que n?o recebem benef?cios sociais, essa possibilidade aumenta para 1,93 vezes. A an?lise de regress?o log?stica hier?rquica foi realizada para os tr?s fatores (1- agravos em sa?de mental, 2- doen?as cr?nicas e 3- doen?as de ossos e coluna). Na an?lise multivariada os fatores associados ?s doen?as e agravos nas comunidades quilombolas, no que tange ao fator 1 foram: recebimento de benef?cios sociais (OR=1,63 IC80%:1,07; 2,50); material utilizado na constru??o da casa (OR=3,22; IC80%:1,17; 8,80); destino do lixo (OR=1,51 IC80%:1,07; 2,13); ter banheiro (OR=2,82; IC80%:1,17; 6,77); autoavalia??o de sa?de (OR=2,64 IC80%: 1,92; 3,65); tipo de medica??o: (OR=0,15; IC80%:0,05; 0,45); problemas com c?ries/canal (OR=1,47 IC80%:1,07; 2,01); idade (OR=1,84; IC80%:1,19; 2,84) e sexo (OR=0,48 IC80%: 0,34; 0,67). Em rela??o ao fator 2 foram: material utilizado na constru??o da casa (OR=3,18; IC80%:1,09; 9,28); ter banheiro (OR=3,69 IC80%:1,36; 10,01); idade (OR=1,87; IC80%: 1,18; 2,95) e sexo (OR=0,47; IC80%:0,32; 0,68). No fator 3 as vari?veis foram: anos de estudo (OR=1,77; IC80%:1,20; 2,62); autoavalia??o de sa?de (OR=1,64; IC80%:1,15; 2,32); tipo de medica??o (OR=6,12; IC 80%:2,59; 14,4) e idade (OR=1,61; IC80%:1,03; 2,51). Conclus?es: Produziram-se evid?ncias cient?ficas acerca das condi??es de vida e sa?de das comunidades quilombolas do munic?pio de Feira de Santana-BA e dos fatores associados ?s doen?as e agravos que mais atingem essas popula??es. Nesta dire??o, verificou-se que as doen?as e agravos nas popula??es quilombolas s?o determinados por fatores demogr?ficos, socioecon?micos, ambientais e das condi??es de sa?de. Espera-se que os resultados encontrados subsidiem novas pesquisas com essa popula??o e que possam contribuir para a implementa??o de pol?ticas sociais e de sa?de espec?ficas, assim como para a realiza??o de interven??es intersetoriais com aplicabilidade loco-regional.
49

Bourian ou la danse des maîtres : circulations et enjeux identitaires des Agudàs, les Brésiliens du Bénin / Bourian, or the dance of the masters : circulation and identity issues among the Agudas, the Brazilians of Benin

De Athayde, Joao Augusto 21 November 2018 (has links)
Descendants à la fois de négriers et d'anciens esclaves du Brésil « retournés » tout au long du XIXe siècle aux actuels Bénin, Togo et Nigeria, les Agudàs, connus aussi comme « les Brésiliens du Bénin », basent leur identité sur des évocations à leurs origines brésiliennes. Un des principaux marqueurs identitaires des Agudàs est la fête de la bourian (« petite ânesse » en portugais), qui réunit chrétiens et musulmans autour d'une sortie de masques très codifiée, où l'on chante – sans comprendre les textes – des airs de samba en portugais, langue qui n'est plus parlée dans cette région d'Afrique. Les divers groupes de bourian, souvent en concurrence les uns avec les autres, évoquent de façon ludique les ancêtres brésiliens, dans un contexte dynamique où chaque population locale réalise des sorties de masques liés aux vodouns. Centrée sur le Bénin méridional, cette thèse cherche à saisir le sens, les enjeux identitaires et les circulations autour de la bourian, tout en gardant une perspective historique et un regard comparatif avec le Brésil. / The Agudas, also known as "the Brazilians of Benin", are the descendants of both slave traders and former slaves who "returned" from Brazil to today's Benin, Togo and Nigeria during the 19th century. To this day, they base their identity on evocations of their Brazilian origins. One of the main identity markers of the Agudas is the festival of the Bourian (a Portuguese word meaning "little she-donkey"), which brings Christians and Muslims together around a codified masquerade, where samba tunes are sung – with no understanding of their lyrics – in Portuguese, a language that is no longer spoken in this region of Africa. The various Bourian groups, often in competition with each other, evoke in a playful way their Brazilian ancestors, in a dynamic context where each local population carries out masquerades related to the vodoun. Focusing on Southern Benin, this thesis aims to understand the meaning of the Bourian, as well as the identity issues and circulations in which the Bourian is involved, while keeping an historical and comparative perspective with Brazil.
50

Etude de la plasticité évolutive et structurale des génomes de plantes / Study of evolutionary and structural plasticity of plant genomes

Murat, Florent 22 July 2016 (has links)
Les angiospermes (ou plantes à fleurs) regroupent environ 350 000 espèces ayant divergé il y a 150 à 200 millions d’années en deux familles botaniques principales, les monocotylédones (les orchidées, les palmiers, les bananiers, les joncs, les graminées...) et les eudicotylédones (les Brassicaceae, les Rosaceae, les légumineuses...) représentant respectivement 20% et 75% des plantes à fleurs. Les angiospermes font l’objet de nombreux travaux de recherche, en particulier en génomique depuis 2000 avec le séquençage du premier génome de plantes (Arabidopsis thaliana) qui a précédé le décryptage des génomes d’un nombre important d’autres espèces modèles et/ou d’intérêt agronomique (environ 100 aujourd’hui). L’accès croissant à la séquence des génomes de plantes a permis de mettre à jour une importante diversité structurale de leur génome, en termes de taille physique, de nombre de chromosomes, de nombre de gènes et de richesse en éléments transposables. Les forces évolutives ayant permis une telle diversité structurale des génomes au cours de l’évolution sont au cœur des travaux de cette thèse. La paléogénomique se propose d’étudier à travers la reconstruction de génomes ancestraux, comment ces espèces ont divergé à partir d’ancêtres communs et quels mécanismes ont contribué à une telle plasticité de structure génomique. Dans cet objectif, les travaux de cette thèse ont mis en œuvre des méthodes basées sur la génomique comparée permettant l’étude de l’évolution structurale des génomes via la reconstruction des génomes ancestraux fondateurs des espèces modernes. Ainsi, un génome ancestral des angiospermes a été reconstruit constitué de 5 chromosomes et porteur de 6707 gènes ordonnés sur ceux-ci, permettant d’intégrer dans un même modèle les monocotylédones et les eudicotylédones et élucider leur histoire évolutive, notamment pour les espèces d’intérêt agronomique majeur telles que les céréales, les rosids et les Brassicaceae. L’inférence de ces génomes ancestraux des plantes modernes a permis l’identification et l’étude de l’impact des évènements de polyploïdie (doublement génomique), ubiquitaires chez les plantes. Nous avons montré que les génomes tendent à revenir à une structure diploïde suite à un évènement de polyploïdie. Cette diploïdisation structurale se fait au niveau caryotypique (par le biais de réarrangements chromosomiques impliquant la perte des centromères et télomères ancestraux) mais aussi géniques (par le biais de pertes de gènes ancestraux en double copies). Il a été montré que cette perte se faisait préférentiellement sur un des sous-génomes post-polyploïdie, menant au phénomène de « dominance des sous-génomes ». Ces biais de plasticité structurale (on parle de compartimentation de la plasticité) se font différentiellement entre les espèces, les chromosomes, les compartiments chromosomiques mais aussi les types de gènes, aboutissant à la diversité structurale observée entre les génomes modernes de plantes. Ces travaux qui rentrent dans le cadre de la recherche fondamentale ont également un fort aspect appliqué à travers la recherche translationnelle en ayant permis de créer des passerelles entre les différentes espèces travaillées en agriculture. Le passage d’une espèce à une autre via les génomes ancestraux fondateurs reconstruits permet notamment le transfert de connaissances des gènes ou de régions d’intérêt des espèces modèles aux espèces cultivées. Les travaux de thèse, par la reconstruction d’ancêtres, permettent une comparaison de haute-résolution des génomes de plantes et in fine l’étude de leur plasticité acquise au cours de l’évolution, et revêtent donc à la fois un aspect fondamental (pour comprendre l’évolution des espèces) mais aussi appliqué (pour l’amélioration des espèces d’intérêt agronomique à partir des modèles). / Angiosperms (or flowering plants) consist in approximatively 350 000 species that have diverged 150 to 200 million years ago in two main families, monocots (orchids, palm trees, banana, bulrushes, grasses...) and dicots (Brassicaceae, Rosaceae, legumes...) representing respectively 20% and 75% of flowering plants. Angiosperms are the subject of intense researches, in particular in genomics since 2000 with the sequence release of the first plant genome (Arabidopsis thaliana) preceding a large number of genomes of plant models and/or species of agronomical interest (around 100 today). Increasing access to plant genome sequences has allowed the identification of their structural diversity, in terms of genome size, number of chromosomes and genes as well as transposable element content. The evolutionary forces that have shaped such structural genomic divergence are at the center of this thesis. Our paleogenomics approach will investigate, through ancestral genome reconstructions, how modern species have diverged from common ancestors and which mechanisms have contributed to such present-day genome plasticity. In this thesis, we have developed methods based on comparative genomics to study plant genome evolution and reconstruct ancestral genomes, extinct progenitors of the modern angiosperm species. An ancestral angiosperm genome has been reconstructed made of 5 chromosomes and 6707 ordered genes allowing the integration in the same model of monocots and eudicots and finally elucidating evolutionary trajectories for species of major agricultural interest such as cereals, rosids and Brassicaceae. The reconstructed paleohistory of modern flowering plants enabled the identification as well as the investigation of the impact of polyploidy events (WGD, whole genome duplications), ubiquitous in plants, as a major driver of the observed structural plasticity of angiosperms. We established that genomes tend to return to a diploid status following a polyploidy event. This structural diploidization is performed at the karyotypic level through chromosomal rearrangements (involving ancestral centromeres and telomeres losses) as well as the gene level (through ancestral duplicates loss). It has been shown that this diploidization is preferentially done on one of the post-polyploidy subgenome, leading to the "sub-genome dominance" phenomenon. This structural plasticity bias (also referenced as plasticity partitioning) is acting differentially between species, chromosomes, chromosomal compartments, gene types, resulting in the structural diversity observed between the present-day plant genomes. This thesis is clearly within the scope of fundamental researches but also has a strong applied objective through translational research in creating bridges between species of major relevance for agriculture. The comparison of one species to another through the reconstructed ancestral genomes allows transferring knowledge gained on genes or any region of interest from model species to crops. Paleogenomics, in reconstructing ancestral genome and unveiling the forces driving modern plant genome plasticity, is therefore of fundamental (toward understanding species evolution) but also applied (toward improving orphan species from knowledge gained in models) objectives.

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