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Made available in DSpace on 2015-03-05T16:20:42Z (GMT). No. of bitstreams: 0 Previous issue date: 24 / Bolsa para curso e programa de Pós Graduação / Pequenos roedores formam um importante elemento faunístico na Floresta com Araucária. Em geral, considera-se que há uma forte relação entre a produção de sementes (pinhões) pela Araucaria angustifolia e a abundância desses animais. Isso devido ao alto conteúdo energético dos pinhões e alta produção dessas sementes, concentrada principalmente nos meses de inverno, quando há um decréscimo na disponibilidade de outros recursos tróficos. No presente estudo, avaliei a importância da A. angustifolia na dieta de pequenos roedores silvestres em área de Floresta com Araucária (Estação Ecológica de Aracuri-Esmeralda, no município de Muitos Capões, RS, Brasil). Realizei sete séries mensais ou bimestrais de captura de pequenos roedores (sete noites de captura por série), de outubro/2008 a julho/2009, representando períodos sem (out/08 a fev/09) e com (abr a jul/09) o recurso pinhão disponível na floresta. Utilizei 30 armadilhas do tipo “pitfall” (baldes de 62 litros) e 50 armadilhas tipo ratoeira (“snap trap”). Capt / Small rodents comprise an important faunal component of the Brazilian Araucaria Forests. It is suggested that there is a strong relation between seed production of the araucaria „pine‟ Araucaria angustifolia and small-rodent abundance. Such relation would be due to the high energetic content of this conifer‟s seeds (known as „pinhões‟) and also high seed production. Such production is concentrated during autumn and winter months, when there is reduction in overall resource availability. In the present study I evaluated the importance of A. angustifolia in the diet of wild small rodents in an area of Araucaria Forest in southern Brazil (Ecological Station of Aracuri-Esmeralda, Muitos Capões, RS, Brazil). I conducted seven capture sessions (seven nights each) monthly of bi-monthly from October/2008 to July/2009, representing a period out of A. angustifolia seed production (October to February) and during seed production (April to July). I used 30 pitfall traps (62 l) and 50 snap traps. Dur

Une reconnaissance appropriée des parasites est essentielle pour une réponse immunitaire efficace, assurant l'activation adéquate des mécanismes de défense immunitaire. Chez les vertébrés, il a été démontré que les gènes codant pour les récepteurs de l'immunité adaptative impliqués dans la reconnaissance des agents pathogènes sont soumis à une intense pression sélective. En revanche, beaucoup moins d’études se sont intéressées à la sélection agissant sur les récepteurs de l'immunité innée. Le but de cette thèse est de décrire la variabilité naturelle des gènes de l'immunité innée impliqués dans la détection des agents pathogènes chez les rongeurs et d’analyser les mécanismes responsables de leur évolution. Ce travail s’est focalisé principalement sur les rongeurs de la sous-famille des Murinae et de leur rôle potentiel en tant que réservoirs d’agents pathogènes dangereux pour l’Homme. Tout d´abord nous avons étudié la variabilité intraspécifique de cinq Toll-like récepteurs ciblant les bactéries (TLR1, TLR2, TLR4, TLR5 et TLR6) pour des lignées consanguines de souris domestiques issues d’une population sauvage de deux sous-espèces : Mus musculus domesticus (Mmd) et Mus musculus musculus (Mmm). Les souches consanguines constituent un outil adapté à l'étude de la variabilité des gènes immunitaires car elles confèrent une information sur les allèles présents dans les populations naturelles tout en bénéficiant de génotypes homozygotes. Les résultats les plus significatifs concernent la découverte d'un codon stop dans l'exon 2 du Tlr5 chez une lignée de Mmm et l’absence de variabilité du Tlr4 chez Mmd. A la suite de ces résultats, nous avons décidé de vérifier si l‘absence de polymorphisme du Tlr4 chez Mmd reflète une absence de variabilité dans les populations naturelles, ou si il s’agit plutôt d’un effet de l'échantillonnage ou des croisements ultérieurs. Nous avons donc séquencé le gène Tlr4 pour les deux sous-espèces provenant de la région du Paléarctique Occidentale (au total 39 Mmm et 62 Mmd) puis nous avons comparé ces résultats avec la variabilité génétique d’un gène mitochondrial (cytochrome b). Nous avons confirmé notre prédiction : la variabilité de Tlr4 chez Mmd est fortement réduite par rapport à Mmm, probablement à cause d’agents pathogènes ayant exercé une sélection purifiante chez Mmd durant la colonisation vers l’ouest. Cependant, l'influence de mécanismes évolutifs neutres, tel que la dérive consécutive à un goulot d’étranglement démographique, ne peut être exclue sur la base de nos données. La dernière partie a été consacrée à la comparaison interspécifique de deux récepteurs : TLR4 et TLR7. Ces deux TLRs se différencient à la fois par leur localisation et leur capacité de détection. TLR4 est un TLR extracellulaire reconnaissant principalement les ligands bactériens, essentiellement les lipopolysaccharides, tandis que TLR7 est localisé dans la cellule et détecte les virus à ARN simple brin. L‘objectif était de décrire la variabilité inter-spécifique de chaque récepteur et de révéler les mécanismes de sélection s’exerçant sur ces gènes au cours de leur évolution sur une échelle de temps plus importante. Nous avons analysé 23 espèces de Murinae provenant surtout d’Asie. Nos résultats suggèrent que la sélection purifiante est la force principale ayant agit sur l’évolution des deux TLRs. Cependant, nous avons également mis en évidence des épisodes de sélection diversifiante qui ont pu être à l’origine des variations intra-spécifiques de TLRs observée aujourd’hui chez les rongeurs. Des sites sous sélection positive sont principalement concentrés dans les domaines extracellulaires des deux récepteurs, domaines responsables de la reconnaissance des agents pathogènes. Enfin, la comparaison entre ces deux TLRs montre que le TLR7 est soumis à une sélection négative plus forte. Cette sélection peut s’expliquer en raison des interactions du TLR7 avec les acides nucléiques viraux. / Appropriate recognition of parasites is crucial for effective immune response, ensuring activation of adequate defence mechanisms. In vertebrates, it has frequently been demonstrated that genes encoding proteins involved in pathogen recognition by an adaptive immune system are often subject to intense selection pressures. On the contrary, much less information has been provided on the evolution of recognition mechanisms of innate immunity. The aim of this thesis is to describe the pattern of natural variation of innate immunity genes involved in pathogen recognition in rodents and to analyze the mechanisms of their evolution. We used murine rodents (subfamily Murinae) as a principal model group because they are potential reservoirs of various pathogens dangerous to humans. First, we studied the intraspecific variability of five bacterial sensing Toll-like receptors (TLR1, TLR2, TLR4, TLR5, and TLR6) in inbred strains derived from two subspecies of the house mouse (M. m. musculus, hereafter abbreviated as Mmm and Mus musculus domesticus, Mmd). Wild-derived inbred strains are suitable tools for studying variation of immunity genes because they provide information about alleles that occur in natural populations, and at the same time they occur at homozygous state. The most significant results include the findings of a stop codon in exon 2 of the Tlr5 gene in one Mmm strain and no variability in Tlr4 of Mmd. Following these results we decided to check whether the absence of Tlr4 polymorphism in Mmd reflects the pattern found in natural populations, or whether it is a consequence of insufficient sampling or subsequent breeding. We therefore sequenced Tlr4 in both subspecies across a large part of the Western Palearctic region (in total 39 Mmm and 62 Mmd individuals), then we compared these results with variability on mitochondrial DNA (cytochrome b). The result confirmed our prediction that observed variability in Mmd is strongly reduced also in free-living populations (compared to Mmm), probably due to strong purifying selection by pathogens with which they met during the westward colonization. However, the influence of random evolutionary processes (e.g. drift during bottlenecks) cannot be excluded based on our data. At the intraspecific level, we could not find any sign of positive selection. The last part of my dissertation is devoted to interspecific comparison of two receptors, TLR4 and TLR7. These two TLRs differ in the exposure and the ligands detection. TLR4 is an extracellular receptor detecting mainly bacterial ligands (especially lipopolysaccharides), while TLR7 is located inside the cell and detects ssRNA viruses. The aim of this part of the thesis was to describe variability of both receptors at the interspecific level and to reveal selection forces acting on TLRs in longer evolutionary time scale. In total we analyzed 23 rodent species of the subfamily Murinae in Europe, Asia and Africa. Our results suggest that purifying selection has been a dominant force in evolution of the Tlr4 and Tlr7 genes, but we also demonstrated that episodic diversifying selection has shaped the present species-specific variation in rodent Tlrs. Sites under positive selection were concentrated mainly in the extracellular domain of both receptors, which is responsible for ligand binding. The comparison between two TLRs lead us to the conclusion that the intracellular TLR7 is under much stronger negative selection pressure, presumably due to its interaction with viral nucleic acids.

Com o objetivo de identificar Toxoplasma gondii e Neospora caninum em roedores urbanos da Grande São Paulo (SP) 217 roedores (quatro camundongos -Mus musculus, 20 ratazanas - Rattus norvegicus e 193 ratos de telhado - Rattus rattus) foram capturados entre abril de 2005 e fevereiro de 2008, para realização do diagnóstico biológico e molecular. Das 20 ratazanas (Rattus norvegicus) capturadas apenas uma foi positiva para T. gondii pelo bioensaio, correspondendo a 5% de positividade entre as ratazanas e 0,46% entre todos os roedores capturados. O isolado obtido dessa ratazana foi caracterizado como genótipo recombinante I, III e u-1 por PCR-RFLP, similar ao isolado previamente descrito e obtido de duas ovelhas e um gato, todos do Estado de São Paulo. Quatro amostras de roedores negativos ao bioensaio resultaram como positivas ao T. gondii pela nested PCR B1. Entretanto, quando submetidas à nested PCR ITS1 e à restrição enzimática (RFLP) não houve confirmação desse resultado em três delas. Em relação ao N. caninum, amostras de tecido cerebral e cardíaco de 121 roedores foram examinadas por nested PCR Nc5, tendo sido encontradas 12 amostras positivas, provenientes de 10 roedores. Quando submetidas à nested PCR ITS1 e à restrição enzimática (RFLP) N. caninum não foi confirmado em nenhuma das amostras. Este estudo conclui que a ocorrência de T. gondii e N. caninum em roedores urbanos da Grande São Paulo (SP) é baixa, sugerindo que estes animais não possuem papel importante na cadeia epidemiológica como reservatórios desses agentes para predadores como os cães e gatos urbanos. / In order to identify Toxoplasma gondii and Neospora caninum in urban rodents from the Great São Paulo (SP) 217 rodents (four Mus musculus, 20 Rattus norvegicus and 193 Rattus rattus) were captured between April 2005 and February 2008 to biological and molecular diagnosis. One out of the 20 Rattus norvegicus was considered positive by bioassay in mice, corresponding to a 5% positivity among Rattus norvegicus and a 0.46% positivity considering all captured rodents. The isolate from this rat was characterized as a recombinant I, III and u-1 genotype by RFLP-PCR. This characterization had been previously described from isolates obtained from two sheep and one cat also from São Paulo state. Four samples from rodents with negative results by bioassay were positive to T. gondii by nested PCR B1. However, when tested with nested PCR ITS1 and RFLP these results were not confirmed in three of these samples. Regarding N. caninum, brain and heart samples of 121 rodents were examined by nested PCR Nc5 and 12 samples from 10 rodents were positive. When tested with nested PCR ITS1 and RFLP all of these samples turned out to be negative. This study concludes that T. gondii and N. caninum have low occurrence in urban rodents in the Great São Paulo area, and they are not important as T. gondii and/or N. caninum reservoirs to predators like urban cats and dogs.

As relações filogenéticas em Rodentia são complexas, sendo a posição de Hystricognathi controversa quando analisada por dados morfológicos e moleculares. O presente estudo propõe uma reavaliação desta filogenia a partir de uma perspectiva comportamental. Seqüências probabilísticas do comportamento de autolimpeza (grooming) foram obtidas, através do programa EthoSeq, em um grupo de 12 espécies de roedores. O grupo interno é constituído por cinco Sciurognathi [Calomys callosus (Cc), Mesocricetus auratus (Ma), Rattus norvegicus (Rn), Mus musculus (Mm), e Meriones unguiculatus (Mu)] e sete Hystricognathi [Cavia aperea (Ca), C. porcellus (Cp), C. intermedia (Ci), Coendou prehensilis (Cop), Trinomys yonenagae (Ty), Thrichomys pachyurus (Tp) e Thrichomys laurentius (Tl), sendo esta espécie representada por duas populações coletadas na Bahia (BA) e no Piauí (PI), respectivamente). Duas espécies representaram os grupos externos: Felis silvestris f. catus e Oryctolagus cuniculus. A análise de sinal filogenético em seqüências de autolimpeza mostra que é necessário o uso de um conjunto de comportamentos organizados em diferentes graus de complexidade (unidades isoladas, díades, e seqüências mais longas) para a resolução das relações nos diferentes níveis taxonômicos estudados. Para a análise cladística usou-se o programa TNT e uma matriz composta por 23 caracteres contínuos (freqüência de autolimpeza) e 7.152 numéricos (seqüências de autolimpeza). A única árvore parcimoniosa obtida foi: (Fc, (Oc, (Cop, (Ci, (Ty, (((Ca, Cp), ((Tl-BA, (Tp, Tl-PI)), ((Mm, Rn), (Mu, (Cc, Ma)))))))))). A obtenção deste resultado mostra a adequação do uso de caracteres comportamentais no estudo de relações filogenéticas mesmo em grupos complexos 8 como Rodentia. Freqüência de autolimpeza é filogeneticamente informativo. Os resultados confirmam monofilia de Rodentia mas não resolvem a questão da monofilia de Hystricognathi. Indicam ainda que as duas populações de Thrichomys laurentius são distintas. Sugere-se que outros caracteres comportamentais em combinação com caracteres morfológicos e/ou moleculares devam ser incluídos em análises filogenéticas a fim de contribuir para esclarecimentos a respeito da evolução dos roedores, principalmente os histricognatas da América do Sul. / The phylogenetical relationships within Rodentia are complex, and the position of Hystricognathi differs when estimated through different kinds of data (morphology or DNA). This paper focuses on a still different kind of data: we estimate the phylogeny of the group through behavioral characters. We obtained probabilistic grooming sequences with the program EthoSeq, in a group of 12 rodent species. The ingroup consisted of five Sciurognathi [Calomys callosus (Cc), Mesocricetus auratus (Ma), Rattus norvegicus (Rn), Mus musculus (Mm), e Meriones unguiculatus (Mu)] and seven Hystricognathi [Cavia aperea (Ca), C. porcellus (Cp), C. intermedia (Ci), Coendou prehensilis (Cop), Trinomys yonenagae (Ty), Thrichomys pachyurus (Tp) e Thrichomys laurentius (Tl), this last species represented by two different populations, one from Bahia and another from Piauí state. The outgroup consisted of two species: Felis silvestris f. catus and Oryctolagus cuniculus. The analysis shows that the use of different levels of behavioral complexity (isolated behavioral units, sequences of two units dyads, and longer sequences routines) is necessary for the resolution of the relationships of the taxa studied. The program TNT was used for the cladistic analysis of a matrix with 23 continuous characters (frequency of grooming units) and 7152 discrete characters (grooming sequences). We obtained one single most parsimonious tree: (Fc, (Oc, (Cop, (Ci, (Ty, (((Ca, Cp), ((Tl-BA, (Tp, Tl-PI)), ((Mm, Rn), (Mu, (Cc, Ma)))))))))). This result shows that behavioral characters are adequate to solve the internal relationships even of complex groups such as Rodentia. There is phylogenetic signal in frequency of grooming units. Although Rodents result monophyletic in our analysis, we could not solve the relationships within Hystricognathi. The two populations of Thrichomys laurentius appear as 10 distinct species. We suggest that other behavioral characters should be combined with other, morphological and/or molecular databases, in order to clarify the relationships within Rodentia, specially within the South America histricognaths.

Made available in DSpace on 2016-04-28T14:56:36Z (GMT). No. of bitstreams: 1 2008 - Heloiza Helena de Oliveira Morelli Amaral.pdf: 1392333 bytes, checksum: e9a8a156b5bb7fbc58a31fe201039311 (MD5) Previous issue date: 2008-11-28 / From October 2005 to October 2007, rodents and marsupials were captured at Pedra Branca State Park, Rio de Janeiro, RJ. This research aimed to characterize the vegetation concerning the study area; to check the existence of a correlation between mesoclimate and microclimate in relation to the presence of parasites and hosts; to identify the dynamics of the hosts and parasites population throughout the seasons and verify the stratification of the small rodents and marsupials fauna as well as the ectoparasitarian fauna. Six spaces of capture were highlighted, in different levels of height. Three types of traps were used, Sherman, Tomahowk and Francesinha, with different baits distributed in five transects. A hundred and sixty mammals were captured, 96 specimens of marsupials and 64 of rodents from the following species: Akodon cursor, Oligoryzomys nigripes, Rattus norvergicus, Rattus rattus, Guerlinguetus ingrami, Sphigurus villosus, Didelphis aurita, Marmosops incanus, Micoureus paraguayanus, Metachirus nudicaudatus, Monodelphis americana and Philander frenatus. It was possible to observe that in hotter (July and August) and drier (December, January and February) months, the number of animals captured is much lower. The vegetation present in the collection areas (in the six levels researched) is composed by secondary vegetation in different stages of regeneration. The areas placed in levels 150, 200, 300 and 400 m can be classified as areas at initial and medium stage of regeneration, while, the areas situated in levels 500 and 600 m the classification is of areas at medium to advanced stage of regeneration. The correlation between the environment (relative humidity, temperature and pluviometric index) and the ectoparasites was only significant to the ticks, showing that, the higher the temperature, the higher is the number of ticks. The dominant species is D. aurita (35%). Three hundred and seventy specimens of ectoparasites were collected: 162 fleas, 105 ticks and 103 lice. The parasites found were: Siphonaptera: Adoratopsylla (Adoratopsylla) antiquorum ronnai, Adoratopsylla (Tritopsylla) intermedia intermedia, Polygenis (Polygenis) occidentalis occidentalis, Polygenis (Polygenis) rimatus, Polygenis (Polygenis) steganus, Polygenis (Neopolygenis) atopus, Ctenocephalidae felis felis, Acari (Ixodidae): Amblyomma geayi, Amblyomma longirostre, Amblyomma scutatum, Amblyomma spp., Ixodes amarali, Ixodes auritulus, Ixodes didelphidis, Ixodes loricatus, Ixodes luciae, Ixodes spp., Phthiraptera: Poliplax spinulosa, Hoplopleura sciuricola, Eutrichophilus minor and Eutrichophilus cercolabes. The siphonapterus obtained the highest prevalence coefficient (28,13%) and the highest abundance index (1,01 flea/host). The phthirapters presented the highest mean intensity of parasitism (17,17 lice/host). The correlation between the numbers of rodents captured and the levels was not significant (rs = 0,23, p = 0,6) and for the marsupials the correlation was negative and also not significant (rs = -0,6, p = 0,2). Polygenis (P.) occidentalis occidentalis was found at the highest frequency (20,8%) among the rodents and in relation to the marsupials, Adoratopsylla (T.) intermedia intermedia was the most frequent (77,7%). E. cercolabes presented the highest frequency (91,5%) among lice; among ticks the highest frequency was of Ixodes loricatus. / No per?odo de outubro de 2005 at? outubro de 2007, foram capturados roedores e marsupiais no Parque Estadual da Pedra Branca, Rio de Janeiro, RJ. Este trabalho objetivou caracterizar a vegeta??o da ?rea de estudo; verificar se existe correla??o entre mesoclima e microclima com rela??o ? presen?a de parasitos e hospedeiros; identificar a din?mica das popula??es de hospedeiros e parasitos ao longo das esta??es do ano e verificar a estratifica??o da fauna de pequenos roedores e marsupiais e da fauna ectoparasit?ria. Foram marcados seis pontos de captura, em diferentes cotas. Utilizou-se tr?s tipos de armadilhas, Sherman. Tomahowk e Francesinha, com diferentes iscas e dispostas em cinco transectos. Capturou-se 160 mam?feros, sendo 96 esp?cimes de marsupiais, das esp?cies: Didelphis aurita, Marmosops incanus, Micoureus paraguayanus, Metachirus nudicaudatus, Monodelphis americana e Philander frenatus, e 64 de roedores, das esp?cies: Akodon cursor, Oligoryzomys nigripes, Rattus norvergicus, Rattus rattus, Guerlinguetus ingrami, Sphigurus villosus,. A vegeta??o presente nas ?reas de coleta (nas seis cotas pesquisadas) ? composta por vegeta??o secund?ria em diferentes est?gios de regenera??o. As ?reas situadas nas cotas 150, 200, 300 e 400 metros podem ser classificadas como ?reas que est?o em est?gio de inicial a m?dio de regenera??o, enquanto, as ?reas situadas nas cotas 500 e 600 metros a classifica??o ? de ?reas em est?gio de m?dio a avan?ado de regenera??o. A correla??o entre o ambiente (umidade relativa do ar, temperatura e ?ndice pluviom?trico) e os ectoparasitas s? foi significativa para os carrapatos, demonstrando que, quanto maior a temperatura, maior ? o n?mero de carrapatos. Observou-se que nos meses de julho e agosto (meses mais secos) e nos meses de dezembro, janeiro e fevereiro (mais quentes) o n?mero de animais capturados ? muito baixo. A esp?cie dominante ? D. aurita (35%). Coletou-se 370 esp?cimes de ectoparasitas, sendo: 162 pulgas, 105 carrapatos e 103 piolhos. Os parasitos encontrados foram: Siphonaptera: Adoratopsylla (Adoratopsylla) antiquorum ronnai, Adoratopsylla (Tritopsylla) intermedia intermedia, Polygenis (Polygenis) occidentalis occidentalis, Polygenis (Polygenis) rimatus, Polygenis (Polygenis) steganus, Polygenis (Neopolygenis) atopus, Ctenocephalidae felis felis; Acari (Ixodidae): Amblyomma geayi, Amblyomma longirostre, Amblyomma scutatum, Amblyomma spp., Ixodes amarali, Ixodes auritulus, Ixodes didelphidis, Ixodes loricatus, Ixodes luciae, Ixodes spp.; Phthiraptera: Poliplax spinulosa, Hoplopleura sciuricola, Eutrichophilus minor e Eutrichophilus cercolabes. As pulgas obtiveram o maior coeficiente de preval?ncia (28,13%) e o maior ?ndice de abund?ncia (1,01 pulga/hospedeiro). Os piolhos apresentaram a maior intensidade m?dia de parasitismo (17,17 piolhos/hospedeiro). A correla??o entre o n?mero de roedores capturados e as cotas n?o foi significativa (rs = 0,23, p = 0,6) e para os marsupiais a correla??o foi negativa e tamb?m n?o significativa (rs = -0,6, p = 0,2). Polygenis (P.) occidentalis occidentalis foi encontrada com a maior freq??ncia (20,8%) entre os roedores e em rela??o aos marsupiais, Adoratopsylla (T.) intermedia intermedia foi a mais freq?ente (77,7%). E. cercolabes apresentou a maior freq??ncia (91,5%) entre os piolhos; entre os carrapatos a maior freq??ncia foi de Ixodes loricatus.

A socioecologia estuda a diversidade dos sistemas sociais a partir dos princípios da ecologia comportamental. Roedores são bons modelos para o estudo dos sistemas sociais por apresentarem elevada variação no comportamento social, a qual pode ser uma adaptação selecionada no passado evolutivo e/ou uma resposta adaptativa ao contexto ecológico atual. Estudar preás para investigar a flexibilidade da organização social é relevante porque, apesar de explorarem vários ambientes diferentes, esses animais podem apresentar certa rigidez comportamental. Nesse contexto, a hipótese que avaliamos é a de que a organização social dos preás Cavia magna, um herbívoro pouco estudado, encontrado do Norte do Uruguai ao Sul do Brasil, depende de determinantes ecológicos atuais, sendo uma resposta adaptativa. A hipótese alternativa é a de que a organização social é uma resposta adaptada, limitada por características selecionadas no passado. Para isso, (1) caracterizamos suas interações sociais; (2) avaliamos as distâncias interindividuais durante o forrageamento, (3) analisamos o padrão de agregação dos indivíduos e (4) comparamos seus comportamentos e organização social com os dados disponíveis de uma população da espécie ocorrente no Uruguai e com os dados de Cavia intermedia, uma espécie endêmica das Ilhas Moleques do Sul, em Santa Catarina que apresenta adaptações ao habitat insular. Os preás foram observados em uma área urbana costeira, dentro do campus do Instituto Federal de Santa Catarina (IFSC), em Florianópolis. Esse local apresenta isolamento da população em área pequena e com pouco risco de predação, isto é, uma área semelhante ao habitat insular. Observamos os preás na estação fria-seca e quente-úmida, por 60 dias. Concluímos que a população de C. magna do IFSC é social, pois encontramos grandes tamanhos médios de agregação, elevados Índices de Associação entre os indivíduos, e associações preferenciais em três grupos com conformação típica de harém. Constatamos que são poligínicos, porque o acesso às fêmeas diferiu entre os machos, e estes apresentaram mais comportamentos agonísticos que as fêmeas. A presença de hierarquia de dominância e ausência de comportamento territorialista dos machos indicaram que a poliginia foi sem defesa. Apesar de termos encontrado um sistema social semelhante ao de C. intermedia, não encontramos características típicas de síndrome insular. Dessa forma, corroboramos a hipótese de que a organização social dos preás é uma resposta adaptativa / Socioecology studies social systems applying the behavioral ecology principles. Studying rodents social systems represents a valuable opportunity once this group shows high variations on social behavior, which may be an adaptation selected in evolutionary past and/or an adaptative feedback to the ecological context. Investigate the social organization flexibility by studying cavies is relevant because of its relative behavioral rigidity, despite their occupation of different environments. In this context, we intend to evaluate our hypothesis on the Cavia magna, cavie social organization: it depends on current ecological factors, being an adaptive answer. C. magna is an herbivore found on northern Uruguay and south of Brazil. The alternative hypothesis is that the social organization is an adaptive answer, limited by reaction rules selected on the past. The cavies was observed in a coast urban area, inside of the Instituto Federal de Santa Catarina (IFSC), in continental Florianópolis, Brazil. The population is isolated in a small area with low predatory risk, being similar to an insulated habitat. We collected data on social interaction, interindividual distances during foraging, grouping pattern and sexual ratio. This data was compared to the available data of Cavia intermedia, from the Moleques do Sul archipelago, specie that was probably derived from C. magna and presents adaptations to the insular habitat. Cavies were observed for 60 days in cold-dry and hot-wet season. We have concluded that the studied C. magna population is social, given that we have found relatively large mean groups size, high Association Indexes between individuals, and preferred associations in three clusters with typical harem structure. We have also found that the population is polygynous, because the access to females differed between male individuals, and the males performed significantly more agonistic behaviors than females. The existence of a dominance hierarchy and the absence of male territorial behavior pointed to polygyny without defense. Even though the studied social system is similar to the one observed on C. intermedia, we did not encounter typical insular syndrome features on C. magna. Accordingly, we have supported the hypothesis that the cavies social organization is an adaptive answer

The social mole-rats have often been typecast as extreme examples of mammalian sociality. With their pronounced reproductive skew, status-related contrasts in lifespan and morphology, and the suggestion of a division of labour amongst helpers, mole-rat societies have repeatedly been likened to the structurally complex societies of some eusocial insects. However, because few studies of mole-rats have quantified individual variation in growth and behaviour across long periods of development, it has remained unclear the extent to which mole-rat societies, and the features of individuals within them, should be considered unique amongst social vertebrates. In this thesis, I examine life history variation in Damaraland mole-rats Fukomys damarensis from three perspectives- growth, behaviour, and ageing- to explore how individual developmental trajectories contribute to, and are influenced by, the structure of mole-rat societies. First, I use a large longitudinal dataset to test for the presence of behavioural specialisation in non-breeding mole-rat helpers. I find no indication of individual specialisation in cooperative activities. Instead, individual differences in helping behaviour are largely the result of age-related changes in the extent to which individuals commit to all forms of helping (Chapter 3); refuting the notion of helper castes. I then focus on the variation in growth across non-breeders, developing a novel biphasic model to accurately quantify sex differences in growth and explore the influence of social effects on growth trajectories (Chapter 4). Despite the proposition of intense intrasexual competition in mole-rat societies, there was no clear signature of sex-specific competition on helper growth trajectories. A more conspicuous form of socially-mediated growth in mole-rats is the secondary growth spurt displayed by females that have acquired the dominant breeding position, causing them to become larger and more elongated. By experimentally controlling reproduction in age-matched siblings, I show that rather than being stimulated by the removal from reproductive suppression, this adaptive morphological divergence is achieved through a lengthening of the lumbar vertebrae when breeding is commenced (Chapter 5). With contrasts in size and shape following the acquisition of the breeding role, this status-related growth pattern shares similarities with growth in naked mole-rats and other social vertebrates. Breeders also show a twofold greater lifespan than non-breeders in Fukomys mole-rats, prompting the suggestion that the transition to dominance also sets individuals onto a slower ageing trajectory. To date, there is little evidence to support a physiological basis to lifespan extension in breeders. This assertion is bolstered by the absence of longer telomeres or slower rates of telomere attrition in breeding females compared to non-breeding females residing in groups (Chapter 6), each of which might be expected if breeders age more slowly. I argue that previous studies exploring status-related ageing in captive Fukomys mole-rats have overlooked the importance of demographic processes (and associated behavioural influences) on mortality schedules. Irrespective of the proximate basis of the longer lifespan of breeders, at an interspecific level the social mole-rats are unusually long-lived for their size. A recent large-scale comparative analysis concluded that prolonged lifespan is a general characteristic of all mammalian cooperative breeders, but this conclusion is premature, as in most of the major clades containing both cooperative and non-cooperative species there is no consistent trend towards lifespan extension in cooperative species (Chapter 7). In the case of mole-rats, it seems more likely that their exceptional longevity arises principally from their subterranean habits and related reductions in extrinsic mortality. Overall, these findings demonstrate that cooperative breeding has important consequences for individual life histories, but there is no strong basis for the claim that Damaraland mole-rat societies are markedly different in form than other cooperative breeding societies.

Os roedores murídeos são melhor conhecidos em relação à placentação, porém descrições para outros grupos como os cricetídeos incluindo os \"camundongos do Novo Mundo\" ainda são escassos. Recentemente à placenta e as membranas fetais tem sido considerados fontes promissoras para a obtenção de células-tronco. Em particular, o saco vitelino é estruturalmente diverso e desempenha várias e importantes funções. Por essa razão, o objetivo deste trabalho foi descrever a placentação corioalantóidea e vitelina em Necromys lasiurus. Além de avaliar o potencial do saco vitelino como uma fonte de células-tronco mesenquimais. Para tanto, um total de 10 placentas variando de início ao final de gestação foram analisadas através de técnicas de histologia, imunohistoquímica e microscopia eletrônica, bem como através do cultivo e diferenciação celular, citometria de fluxo e imunocitoquímica. A placenta corioalantóidea discoidal era organizada em uma zona labiríntica, zona juncional e decidua. O labirinto era a região mais importante para as trocas materno-fetal. Próximo ao final da gestação ele apresentou uma barreira hemotricorial com espessura média de 2,41 µm. A zona juncional era composta por sincício e citotrofoblasto. Células trofoblásticas gigantes localizavamse entre a zona juncional e a decidua, assim como nas margens laterais da placenta. A morfologia do saco vitelino visceral invertido variou de acordo com a sua localização e relação com a placenta e o útero. Quando cultivadas, as células aderentes do saco vitelino formaram colônias fibroblastóide (92,13%) e expressaram marcadores de células-tronco mesenquimais e alguns para células precursoras de células-hematopoiéticas. As células apresentaram sucesso quanto às diferenciações osteogênica, adipogênica e condrogênica e não desenvolveram formação tumoral quando injetadas em camundongo nude. Com isso, essas células-tronco despontam como uma fonte terapêutica promissora para a terapia celular. / Murine rodents are well investigated in regard to placentation, but data for other groups such as cricetids including New World mice or Sigmodontinae are sparse. Recently the placenta and fetal membranes are regarded to be promising sources for obtaining stem cells. In particular, the yolk sac is structurally diverse and shows important functions throughout gestation. For this reason, this study aims to describe the chorioallantoic and yolk sac placentation in Necromys lasiurus. In addition, the potential of the yolk sac as a source for mesenchymal stem cells that are not well studied so far will be evaluated. In total, 10 individuals from early gestation to near term were investigated by means of histology, immunohistochemistry and electron microscopy as well as cell culture and differentiation, flow citrometry and immunocytochemistry. The discoidal chorioallantoic placenta was organized in a labyrinth zone, junctional zone, and decidua. The labyrinth was most import for maternal-fetal exchange processes. It possessed a hemotrichorial barrier of about 2.41 µm thickness near term. The junctional zone included syncytial areas and cytotrophoblasts. Trophoblast giant cells were located between the junctional zone and decidua as well as in the lateral margins of the placenta. The morphology of the inverted visceral yolk sac varies according to its location and relationship with the placenta and uterus. When cultured, the adherent cells of the yolk sac formed fibroblastoid colonies (92.13%) and expressed mesenchymal stem cells markers, and some hematopoietic precursor cells markers. They showed successful osteogenic, adipogenic, and chondrogenic differentiation and did not develop tumors when transferred to nude mice. Thus, these cells resulted as stem cells with promising therapeutic values for cell therapy.

The small mammal population of a restricted study area was live-trapped on the University farm at Western Kentucky University from November 1984 through November 1985. A total of 1800 trap-nights yielded 81 different individuals representing five species. Members of the genera Peromyscus and Microtus were the dominant individuals representing over 90% of the total. Also caught were Mus musculus and Blarina brevicauda. The members of the two major genera were examined for population size and dynamics. In addition, a statistical analysis was carried out on the randomness of the location of the home ranges. This analysis gave evidence that the Peromyseus population was centered primarily in the ecotone between field and forest while Microtus was centered exclusively in the field habitat. In addition, the absence or near absence of Microtus for part of the year allowed the Peromyscus population to expand into the field for a short time. Finally, the year long study revealed a characteristic population cycle for each major species due to a combination of reproductive rates, feeding habits and decimation by predation.