Les chauves-souris (Chiroptera) sont reconnues comme réservoirs naturels de nombreux microorganismes, dont certains pathogènes, responsables de maladies sévères chez l’homme. À ce jour, plus de 1 300 espèces de chauves-souris, aux habitats et comportements sociaux multiples, ont été décrites. Cette grande diversité d’espèces reflète l’importante diversité des caractéristiques biologiques, de l’histoire évolutive et de la capacité d’adaptation de cet ordre. Les études immunobiologiques laissent à penser que ces animaux présentent des stratégies antimicrobiennes plus efficientes que les autres mammifères, influencées par leurs caractéristiques spécifiques et par les contraintes pathogéniques associées aux environnements. L’objectif de cette thèse était de mieux comprendre, en utilisant la diversité virale et la circulation du virus rabique comme proxy, comment les contraintes bioécologiques, liées à la phylogénie de l’hôte et à son environnement, pouvaient impacter la diversité virale des chauves-souris, et subséquemment, induire une adaptation locale des gènes de l’immunité. L’ensemble des résultats obtenus montre que les composantes environnementales sont des facteurs clés des diversités virales et immunitaires. Associées aux caractéristiques spécifiques, elles jouent un rôle dans le maintien de ces diversités et déterminent les capacités d'adaptation des chauves-souris. Les processus démographiques semblent également contribuer au maintien des virus dans un environnement donné. Ce travail apporte des éléments de compréhension des mécanismes de maintien et de mise en place des diversités virales et immunitaires qui influencent l'adaptation locale des chauves-souris. / Bats belong to the order Chiroptera and are the only mammals capable of true flight. They are recognized as excellent biodiversity indicators. Furthermore, these animals have been described as natural reservoirs and source of infection for several microorganisms, including pathogens responsible for severe human diseases. Currently, more than 1,300 different bat species are described with different habitats and sociality, reflecting a high diversity of bioecological features, life histories and adaptation capacity. Immunobiological studies suggest that bats present more effective anti-microbial strategies highly influenced by their biological traits as well as by the environmental-associated pathogen pressures. The aim of this thesis was to better understand, using viral diversity and circulation of the rabies virus as a proxy, how bioecological constraints related to the phylogeny and the environment where they evolve, could impact the diversity of hosted viral communities and subsequently induce a local adaptation of immune genes. Altogether, the results obtained during this thesis showed that environmental components were key factors of both viral and immune diversities. Associated with species characteristics, environment plays a key role in shaping both diversities and determines the adaptation ability of bats. Nevertheless, demographic processes should not be overshadowed as they seem to contribute to the maintenance of viruses in a given environment. This work sheds light on the mechanisms maintaining and shaping both viral and immune diversities and subsequently influencing the local adaptation of bats

Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-05-14T12:33:41Z No. of bitstreams: 1 Maria Juliana Gomes Arandas.pdf: 4922822 bytes, checksum: 148127b0ff232a5523d17669ea5ab23c (MD5) / Made available in DSpace on 2018-05-14T12:33:41Z (GMT). No. of bitstreams: 1 Maria Juliana Gomes Arandas.pdf: 4922822 bytes, checksum: 148127b0ff232a5523d17669ea5ab23c (MD5) Previous issue date: 2018-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Bats have peculiar reproductive aspects that evolved in order to adapt to different environmental and climatic conditions. One of the criteria for the understanding about the reproductive biology in bats is the testicular and epididymal morphophysiology. Molossus molossus and Myotis lavali are insectivorous bats, and studies on the reproductive biology of these species are scarce, especially in the Northeast of Brazil. Therefore, it was analyzed the testicular and epididymal histomorphometry as well as testosterone levels of M. molossus and M. lavali from a fragment of Atlantic Forest located between the cities of Tamandaré and Rio Formoso-PE. In total, 23 adult males of M. molossus were studied, being 10 for dry months and 13 for rainy months. Besides that, 34 adult males of M. lavali were analyzed (22 in dry months and 12 in rainy months). After Anesthesia, blood samples were collected to testosterone dosage. Subsequently, the testicles and epididymides were fixed in 10% buffered formalin, and submitted to the routine histological techniques. For the testicles, the following histomorphometric parameters were evaluated: the tubular and intertubular areas, quantification of spermatocytes, rounded and elongated spermatids, Sertoli cells and Leydig cells, while in the epididymis: the tubular, luminal and epithelial areas from the head, body and tail. The results indicated that M. molossus presented higher averages for the tubular and intertubular areas, rounded and elongated spermatids, Leydig cells and testosterone levels. In the epididymis, the tubular, luminal and epithelial areas were larger in rainy months. On the other hand, M. lavali exhibited increased tubular and intertubular areas, number of elongated spermatids, Sertoli cells, Leydig cells and testosterone levels as well as tubular, luminal and epithelial area of the head and tail of the epididymis during the rainy season. Physiologically, males of both species have a high investment in the final stages of spermatogenesis and in the concentration of testosterone. Furthermore, the two species have a greater capacity to store spermatozoa in the region of the tail of epididymis, which relates to the reproductive strategy developed by bats for storage. Although both species exhibit a continuous spermatogenic cycle, it is noted that they adjust their reproduction for the rainy months. / Os morcegos apresentam aspectos reprodutivos peculiares que evoluíram a fim de se ajustar as diferentes condições ambientais e climáticas, e um dos critérios para o conhecimento da reprodução é a morfofisiologia testicular e epididimária. Molossus molossus e Myotis lavali são espécies de morcegos insetívoros, e os estudos referentes a biologia reprodutiva são escassos, principalmente no Nordeste do Brasil. Assim, analisou-se a histomorfometria testicular e epididimária, assim como os níveis de testosterona de M. molossus e M. lavali em um fragmento de Mata Atlântica localizado entre os Municípios de Tamandaré e Rio Formoso-PE. Um total de 23 machos adultos foi selecionado para M. molossus, sendo 10 em meses secos e 13 para meses chuvosos. Ao passo que foram utilizados 34 machos adultos para M. lavali, sendo 22 em meses secos e 12 em meses chuvosos. Após anestesia, as amostras de sangue foram coletadas para a dosagem de testosterona. Os testículos e epidídimos foram removidos e fixados em formal 10% tamponado, e posteriormente submetidos à técnica histológica de rotina. Para o testículo, os seguintes parâmetros histomorfométricos foram avaliados: a área tubular, área intertubular, quantificação dos espermatócitos, espermátides (arredondadas e alongadas), células de Sertoli e células de Leydig, enquanto que no epidídimo: as áreas tubular, luminal e epitelial da cabeça, corpo e cauda. Os resultados indicaram que M. molossus apresentou maiores médias para a área tubular, intertubular, espermátides (arredondadas e alongadas), células de Leydig e níveis de testosterona. No epidídimo, as áreas tubular, luminal e epitelial foram maiores em meses chuvosos. Ao passo que M. lavali na estação chuvosa exibiu um aumento nas áreas tubular e intertubular, nas espermátides alongadas, células de Sertoli, células de Leydig e nos níveis de testosterona, assim como na área tubular, luminal e epitelial da cabeça e cauda do epidídimo. Fisiologicamente, os machos das duas espécies têm um alto investimento nas etapas finais da espermatogênese e na concentração de testosterona. Atrelado a isso, nota-se uma maior capacidade de comportar os espermatozoides na região da cauda do epidídimo, que se relaciona a estratégia reprodutiva desenvolvida pelos morcegos para a estocagem. Embora as duas espécies apresentem um ciclo espermatogênico contínuo, nota-se que ajustam a reprodução para os meses chuvosos.