Os roedores da sub-ordem histricomorfa, na qual a paca está classificada, apresentam placentação hemocorial e desenvolvem uma estrutura peculiar junto a sua placenta denominada de subplacenta. Apesar dos relatos de sua presença em diversas espécies, as possíveis funções dessa estrutura permanecem no âmbito especulativo, devido às variações na forma, dimensão e localização, bem como à falta de estudos experimentais focalizando essa estrutura placentária. Foram utilizadas oito placentas de pacas obtidas nos períodos médio e final de gestação, para avaliações das organizações e constituições teciduais, relações anatômicas do órgão por meio da microscopia de luz e eletrônica, aliadas às técnicas de citoquímica, imunocitoquímica e perfusões de traçadores para a rede vascular. Os resultados demonstraram que a subplacenta da paca estava localizada no ápice da placenta corioalantoidiana, separada desta por um tecido mesenquimal e inserida na parede uterina em íntimo contato com o tecido materno. A subplacenta consistia de estruturas lamelares com um eixo de tecido mesenquimal fetal sobre o qual apoiavam-se arranjos epiteliais de citotrofoblastos e sinciciotrofoblastos. Nas áreas de interfaces dos perímetros da subplacenta em contato com o tecido materno foram encontradas ainda populações de células trofoblásticas gigantes multinucleadas. Essas células trofoblásticas gigantes e sinciciotrofoblastos citoqueratina positivas foram também encontradas distantes do perímetro da subplacenta, invadindo profundamente o endométrio, que se apresenta totalmente desestruturado, contendo vasos sangüíneos com as paredes infiltradas pelas células trofoblásticas e destituídas de revestimento endotelial, confirmada pela reação vimentina negativa pela imunocitoquímica. Essas localizações de células trofoblásticas apontam para a capacidade invasiva das células trofoblásticas tanto através do leito vascular materno quanto pelos interstícios do estroma endometrial. Verificou-se uma área limítrofe de tecido endometrial decidualizado junto ao miométrio que se mantinha íntegra e que aparentemente conteve a invasividade das células trofoblásticas. Nos espaços interlamelares do interior da subplacenta, em meio ao sinciciotrofoblato, foram encontrados materiais amorfos resultantes da degradação do tecido endometrial retidos durante a progressão e crescimento da placenta para o interior da parede uterina. Nesses espaços, não foram encontrados vasos sangüíneos, porém, no eixo mesenquimal da subplacenta, foram constatados vasos sangüíneos de pequeno calibre, todos vimentina positivos, sugerindo a ausência de vascularização através de sangue materno na subplacenta. Pela localização estratégica, acima da placenta principal e pelos aspectos ultra-estruturais das células citotroblasticas presentes nas lamelas, juntamente com sua intensa marcação pelo PCNA, presume-se que as células da subplacenta possam originar as demais células trofoblásticas, particularmente as sinciciais e as gigantes, ao longo do terço médio da gestação. A vascularização da subplacenta avaliada pela perfusão de látex colorido e pela técnica de corrosão e análise em microscopia eletrônica de varredura comprovou a ausência de vasos de origem materna na subplacenta e demonstrou uma irrigação oriunda da artéria fetal que, após capilarização na subplacenta, dirigia-se para os lóbulos da placenta principal. Esta disposição lembra uma circulação do tipo portal, com uma possível recapilarização dos vasos oriundos da subplacenta junto à placenta principal, onde o sangue fetal efetuaria as trocas metabólicas para retornar como sangue oxigenado antes de confluir para a veia fetal no cordão umbilical. / The rodents of suborder hystricomorph, in which is classified the Agouti paca, present hemochorial type placentation and develops an unique structure known as subplacenta. In spite of many report of its presence in several species, the possible functions of this structure related to placenta and pregnancy remains speculative, mainly due to the diversity of form, size, localization and lack of experimental studies focusing such a placental structure. In the present study were used eight placentas collected from paca at midle and end stage of gestation in the aim to evaluate their tissue components and organization, anatomical relation of the organ at light and electron microscopy level, associated with cytochemical and immunocytochemical techniques and perfusion of vascular bed. The results showed the subplacenta was localized at apical portion of chorioallantoic placenta of paca, separated from this by mesechimal tissue and inserted in the uterine wall in intimate contact with maternal tissue. The subplacenta consisted of lamellar structures with mesenchimal axis of fetal origin on which, cytotrophoblast and syncytiotrophoblasts layers were organized as epithelial sheets. The interfaces at peripheral portion of subplacenta in contact with maternal tissue were also found populations of multinucleated giant trophoblast cells. These giant cells and syncytiotrophoblast were cytokeratin positives and were found far from the limits of subplacenta, deeply invading the completely damaged endometrium, as did the maternal vessels showing presence of trophoblast cells in their walls devoid of endothelial cells attested by vimentin and cytokeratin immunostaining. These findings suggest the invasive capability of trophoblast cells either through the maternal vascular bed and interstitium of endometrial stroma. However, it was seen a well defined border line of helthy decidualized endometrium near the miometrium that seems to retain the invasive progression of trophoblast cells. In the interlamellar space of subplacenta formed by syncytiotrophoblast, it was found amorphous materials originated from degradation of endometrial tissue retained during the progression and growth of placenta into the uterine wall. In these interlamellar spaces were not found blood vessels, but in the mesenchimal axes were found vimentin positive small vessels, which suggest absence of maternal vascularization inside the subplacenta. The strategical localization of subplacenta upside of chorioallantoic placenta of paca and the ultra structure of cytotrophoblast cells and their strong reaction to PCNA (proliferating cell nuclear antigen) supports these subplacental cells could be the source of trophoblast cells, namely the giant and syncytiotrophoblast. The vascularization of subplacenta evaluated by stained latex perfusion and by microvascular casting seen at scaning electron microscopy clearly showed the absence of maternal vascularization in the subplacenta. The blood supply of subplacenta seems to be exclusively from fetal artery whieems after capilarization in the subplacenta flows to the lobules of main placenta. Such a blood flow remind the portal type circulation, being the second capilarization of venous type vessels coming from the subplacenta inside the lobulules of the main placenta, where the fetal blood could make the metabolic changes to return with enough oxygenation level before join to the fetal vein in the umbilical cord.

Os roedores da sub-ordem histricomorfa, na qual a paca está classificada, apresentam placentação hemocorial e desenvolvem uma estrutura peculiar junto a sua placenta denominada de subplacenta. Apesar dos relatos de sua presença em diversas espécies, as possíveis funções dessa estrutura permanecem no âmbito especulativo, devido às variações na forma, dimensão e localização, bem como à falta de estudos experimentais focalizando essa estrutura placentária. Foram utilizadas oito placentas de pacas obtidas nos períodos médio e final de gestação, para avaliações das organizações e constituições teciduais, relações anatômicas do órgão por meio da microscopia de luz e eletrônica, aliadas às técnicas de citoquímica, imunocitoquímica e perfusões de traçadores para a rede vascular. Os resultados demonstraram que a subplacenta da paca estava localizada no ápice da placenta corioalantoidiana, separada desta por um tecido mesenquimal e inserida na parede uterina em íntimo contato com o tecido materno. A subplacenta consistia de estruturas lamelares com um eixo de tecido mesenquimal fetal sobre o qual apoiavam-se arranjos epiteliais de citotrofoblastos e sinciciotrofoblastos. Nas áreas de interfaces dos perímetros da subplacenta em contato com o tecido materno foram encontradas ainda populações de células trofoblásticas gigantes multinucleadas. Essas células trofoblásticas gigantes e sinciciotrofoblastos citoqueratina positivas foram também encontradas distantes do perímetro da subplacenta, invadindo profundamente o endométrio, que se apresenta totalmente desestruturado, contendo vasos sangüíneos com as paredes infiltradas pelas células trofoblásticas e destituídas de revestimento endotelial, confirmada pela reação vimentina negativa pela imunocitoquímica. Essas localizações de células trofoblásticas apontam para a capacidade invasiva das células trofoblásticas tanto através do leito vascular materno quanto pelos interstícios do estroma endometrial. Verificou-se uma área limítrofe de tecido endometrial decidualizado junto ao miométrio que se mantinha íntegra e que aparentemente conteve a invasividade das células trofoblásticas. Nos espaços interlamelares do interior da subplacenta, em meio ao sinciciotrofoblato, foram encontrados materiais amorfos resultantes da degradação do tecido endometrial retidos durante a progressão e crescimento da placenta para o interior da parede uterina. Nesses espaços, não foram encontrados vasos sangüíneos, porém, no eixo mesenquimal da subplacenta, foram constatados vasos sangüíneos de pequeno calibre, todos vimentina positivos, sugerindo a ausência de vascularização através de sangue materno na subplacenta. Pela localização estratégica, acima da placenta principal e pelos aspectos ultra-estruturais das células citotroblasticas presentes nas lamelas, juntamente com sua intensa marcação pelo PCNA, presume-se que as células da subplacenta possam originar as demais células trofoblásticas, particularmente as sinciciais e as gigantes, ao longo do terço médio da gestação. A vascularização da subplacenta avaliada pela perfusão de látex colorido e pela técnica de corrosão e análise em microscopia eletrônica de varredura comprovou a ausência de vasos de origem materna na subplacenta e demonstrou uma irrigação oriunda da artéria fetal que, após capilarização na subplacenta, dirigia-se para os lóbulos da placenta principal. Esta disposição lembra uma circulação do tipo portal, com uma possível recapilarização dos vasos oriundos da subplacenta junto à placenta principal, onde o sangue fetal efetuaria as trocas metabólicas para retornar como sangue oxigenado antes de confluir para a veia fetal no cordão umbilical. / The rodents of suborder hystricomorph, in which is classified the Agouti paca, present hemochorial type placentation and develops an unique structure known as subplacenta. In spite of many report of its presence in several species, the possible functions of this structure related to placenta and pregnancy remains speculative, mainly due to the diversity of form, size, localization and lack of experimental studies focusing such a placental structure. In the present study were used eight placentas collected from paca at midle and end stage of gestation in the aim to evaluate their tissue components and organization, anatomical relation of the organ at light and electron microscopy level, associated with cytochemical and immunocytochemical techniques and perfusion of vascular bed. The results showed the subplacenta was localized at apical portion of chorioallantoic placenta of paca, separated from this by mesechimal tissue and inserted in the uterine wall in intimate contact with maternal tissue. The subplacenta consisted of lamellar structures with mesenchimal axis of fetal origin on which, cytotrophoblast and syncytiotrophoblasts layers were organized as epithelial sheets. The interfaces at peripheral portion of subplacenta in contact with maternal tissue were also found populations of multinucleated giant trophoblast cells. These giant cells and syncytiotrophoblast were cytokeratin positives and were found far from the limits of subplacenta, deeply invading the completely damaged endometrium, as did the maternal vessels showing presence of trophoblast cells in their walls devoid of endothelial cells attested by vimentin and cytokeratin immunostaining. These findings suggest the invasive capability of trophoblast cells either through the maternal vascular bed and interstitium of endometrial stroma. However, it was seen a well defined border line of helthy decidualized endometrium near the miometrium that seems to retain the invasive progression of trophoblast cells. In the interlamellar space of subplacenta formed by syncytiotrophoblast, it was found amorphous materials originated from degradation of endometrial tissue retained during the progression and growth of placenta into the uterine wall. In these interlamellar spaces were not found blood vessels, but in the mesenchimal axes were found vimentin positive small vessels, which suggest absence of maternal vascularization inside the subplacenta. The strategical localization of subplacenta upside of chorioallantoic placenta of paca and the ultra structure of cytotrophoblast cells and their strong reaction to PCNA (proliferating cell nuclear antigen) supports these subplacental cells could be the source of trophoblast cells, namely the giant and syncytiotrophoblast. The vascularization of subplacenta evaluated by stained latex perfusion and by microvascular casting seen at scaning electron microscopy clearly showed the absence of maternal vascularization in the subplacenta. The blood supply of subplacenta seems to be exclusively from fetal artery whieems after capilarization in the subplacenta flows to the lobules of main placenta. Such a blood flow remind the portal type circulation, being the second capilarization of venous type vessels coming from the subplacenta inside the lobulules of the main placenta, where the fetal blood could make the metabolic changes to return with enough oxygenation level before join to the fetal vein in the umbilical cord.

Hårfollikeln är en struktur som hittas hos alla däggdjur. Hår skyddar kroppen från UV-ljus, medverkar i kroppens värmereglering och har flera kommunikativa funktioner. Hårets varierande färg inom och mellan arter är både en fascinerande och intresseväckande egenskap som länge har studerats som en modell för genetisk nedärvning. I denna litteraturstudie ges en genomgång av hårfollikelns struktur och funktion, genetiken bakom hårets pigmentering samt didaktiska utmaningar i genetikundervisningen. Interaktioner mellan generna MC1R, ASIP (agouti) och POMC förklaras och exemplifieras. Dessutom diskuteras hur fårfollikeln och de pigmentreglerande generna kan användas i gymnasieskolan som ett exempel för komplicerade genetiska interaktioner. / The hair follicle is a structure found in all mammals. Hair protects the body from UV-induced damage, assists the body in its thermoregulation and has several communicative functions. The great variation in hair colour, both within and between species, is a captivating and intriguing trait that has been used as a model for genetic inheritance for a long time. This literature review features the structure and function of the hair follicle, the genetics behind the pigmentation of the hair as well as didactic challenges in teaching genetics. Interactions between the genes MC1R, ASIP (agouti) and POMC is both explained and illustrated. This review also discusses how the hair follicle and the genes regulating pigmentation can be used as an example of intricate genetic interactions in the upper secondary school. / <p>På grund av Covid-19 skedde presentation, opponering och respondering skriftligt på distans.</p>

Terrestrial mammals affect numerous aspects of plant demography, colonization, and community structure in Neotropical forests. Granivorous mammals destroy seeds via seed predation and seedlings through herbivory, negatively affecting plant fitness. Mammals can also positively affect plants by dispersing or hoarding seeds. Seed fate outcomes are contingent on the interaction between mammal seed handling strategies and the intrinsic anti-predation defenses possessed by seeds. In field experiments at La Selva Biological Station, I investigated how collared peccaries (Pecari tajacu) and Central American agoutis (Dasyprocta punctata) affect five species of large seeds that have various defenses against predation. Overall, peccaries consumed and killed most non-defended and chemically-defended seeds but they could not destroy seeds with physical defenses. Agoutis killed non-defended and physically-defended seeds, but not seeds with chemical defenses. Using seeds of Mucuna holtonii, I investigated how chemical and structural defenses deter mammal and insect seed predation respectively. I also determined how endosperm removal by invertebrates affects seed germination and seedling biomass. Chemical defenses protected seeds from rodents, but not ungulates that digest seeds via pregastric fermentation. Physical defenses protected seeds from invertebrate seed predators, and removal of endosperm negatively affected both seed germination and seedling growth. To determine how scatter-hoarding by agoutis affects seed escape from seed predators, germination, and seedling growth, I created simulated agouti hoards. I also investigated how mammals affect young seedling survival. Hoarding enhanced seed survival, germination, and seedling growth for most species of seeds. Terrestrial mammals killed some seedlings via seed predation rather than by herbivory. Overall, large mammal activity in La Selva negatively affected seed and seedling survival and this likely influences many aspects of forest dynamics.

Muitas espécies de mamíferos selvagens são criadas para produção de carne. No Brasil, a capivara (Hydrochaeris hydrochaeris), a paca (Agouti paca), o cateto (Tayassu tajacu) e a queixada (Tayassu pecari) são criadas comercialmente para este fim, porém são escassas as informações sanitárias a respeito dessas espécies. Assim, o presente estudo teve por objetivo estudar a presença de infecção causada por leptospiras, micobactérias, brucelas e Erysipelothrix spp. em 138 animais dessas quatro espécies, provenientes de nove criadouros e abatidos em estabelecimento com Serviço de Inspeção Federal. Nenhum animal apresentou anticorpos séricos contra brucelas lisas. As capivaras apresentaram a maior freqüência de animais sorologicamente reagentes para leptospiras (54,5%), seguidas das queixadas (39%) e dos catetos (21,7%). O sorovar mais provável mais freqüente para as espécies estudadas foi o Grippotyphosa, seguido do Hardjobovis e do Tarassovi. Das capivaras foram isolados Leptospira santarosai a partir de rim e Mycobacterium xenopi a partir de linfonodo mesentérico. Das queixadas foi isolado Erysipelothrix rhusiopathiae a partir de tonsila. Segundo os bancos de dados Scopus, Pubmed e Cab Abstracts (Ovid), trata-se dos primeiros relatos de isolamento de M. xenopi em capivara e de E. rhusiopathiae em queixada. / Many species of wild mammals are raised for meat production. In Brazil, the capybara (Hydrochaeris hydrochaeris), paca (Agouti paca), collared peccary (Tayassu tajacu) and the white-lipped peccary (Tayassu pecari) are commercially bred, however there is limited sanitary information related to these species. This study aimed to search for the presence of infection caused by Leptospira spp., Mycobacteria spp., Brucella spp. and Erysipelothrix spp. in 138 animals belonging to those species, coming from nine commercial breeders and slaughtered under the Federal Inspection Service. None of these animals presented antibodies against smooth brucellas. The capybaras showed the highest frequency of seropositive animals for leptospirosis (54.4%), followed by the white-lipped peccaries (39%) and the collared peccaries (21.7%). The most frequent serovar was Grippotyphosa, followed by Hardjobovis and Tarassovi. Leptospira santarosai was isolated from the kidneys and Mycobacterium xenopi from the mesenteric lymph nodes of the examined capybaras. Erysipelothrix rhusiopathiae was isolated from the tonsils of one white-lipped peccary. According to the data banks Scopus, Pubmed e Cab Abstracts (Ovid), this is the first report of M. xenopi isolation from capybara and of E. rhusiopathiae from white-lipped peccary.

Muitas espécies de mamíferos selvagens são criadas para produção de carne. No Brasil, a capivara (Hydrochaeris hydrochaeris), a paca (Agouti paca), o cateto (Tayassu tajacu) e a queixada (Tayassu pecari) são criadas comercialmente para este fim, porém são escassas as informações sanitárias a respeito dessas espécies. Assim, o presente estudo teve por objetivo estudar a presença de infecção causada por leptospiras, micobactérias, brucelas e Erysipelothrix spp. em 138 animais dessas quatro espécies, provenientes de nove criadouros e abatidos em estabelecimento com Serviço de Inspeção Federal. Nenhum animal apresentou anticorpos séricos contra brucelas lisas. As capivaras apresentaram a maior freqüência de animais sorologicamente reagentes para leptospiras (54,5%), seguidas das queixadas (39%) e dos catetos (21,7%). O sorovar mais provável mais freqüente para as espécies estudadas foi o Grippotyphosa, seguido do Hardjobovis e do Tarassovi. Das capivaras foram isolados Leptospira santarosai a partir de rim e Mycobacterium xenopi a partir de linfonodo mesentérico. Das queixadas foi isolado Erysipelothrix rhusiopathiae a partir de tonsila. Segundo os bancos de dados Scopus, Pubmed e Cab Abstracts (Ovid), trata-se dos primeiros relatos de isolamento de M. xenopi em capivara e de E. rhusiopathiae em queixada. / Many species of wild mammals are raised for meat production. In Brazil, the capybara (Hydrochaeris hydrochaeris), paca (Agouti paca), collared peccary (Tayassu tajacu) and the white-lipped peccary (Tayassu pecari) are commercially bred, however there is limited sanitary information related to these species. This study aimed to search for the presence of infection caused by Leptospira spp., Mycobacteria spp., Brucella spp. and Erysipelothrix spp. in 138 animals belonging to those species, coming from nine commercial breeders and slaughtered under the Federal Inspection Service. None of these animals presented antibodies against smooth brucellas. The capybaras showed the highest frequency of seropositive animals for leptospirosis (54.4%), followed by the white-lipped peccaries (39%) and the collared peccaries (21.7%). The most frequent serovar was Grippotyphosa, followed by Hardjobovis and Tarassovi. Leptospira santarosai was isolated from the kidneys and Mycobacterium xenopi from the mesenteric lymph nodes of the examined capybaras. Erysipelothrix rhusiopathiae was isolated from the tonsils of one white-lipped peccary. According to the data banks Scopus, Pubmed e Cab Abstracts (Ovid), this is the first report of M. xenopi isolation from capybara and of E. rhusiopathiae from white-lipped peccary.

L'ulcère de Buruli est une maladie infectieuse tropicale présente dans des foyers endémiques. Cette infection essentiellement cutanée est causée par Mycobacterium ulcerans. M. ulcerans est un pathogène opportuniste dont le réservoir est environnemental. Notre revue de la littérature a répertorié les sources environnementales potentielles de cette mycobactérie. Seulement cinq souches de M. ulcerans ont été isolées à partir de prélèvements de l’environnement. Il existe une corrélation inverse entre réchauffement climatique et incidence de l’ulcère de Buruli, peut-être liée à la sensibilité intrinsèque de M. ulcerans aux variations de température, ou bien à des modifications de son écosystème. Dans la perspective d’améliorer les protocoles d’isolement de M. ulcerans à partir de l’environnement, nous avons entrepris une analyse phénotypique à haut débit des substrats carbonés métabolisés par M. ulcerans et le profil obtenu nous a orientés après une recherche bibliographique des principales sources environnementales de ces substrats, vers des interactions plus spécifiques de M. ulcerans avec les bactéries, algues, mollusques et champignons. Les résultats de ce premier travail ont servi de base pour la mise au point de milieux de culture innovants qui nous ont permis d’isoler pour la première fois, une microcolonie de M. ulcerans à partir de fèces d’agouti. Nous avons mis au point une méthode de lecture automatisée des échantillons colorés par la méthode de Ziehl-Neelsen. Notre travail de thèse a produit des protocoles qui ont pour objectif d’être mis en œuvre dans les pays d’endémie, pour préciser les sources et modes de transmission de M. ulcerans aux populations. / Buruli ulcer is a tropical infectious disease present in endemic foci/This mainly cutaneous infection is caused by Mycobacterium ulcerans. M. ulcerans is an opportunistic pathogen from the environment. Our literature review has listed the potential environmental sources of this mycobacterium.. However, only five strains of M. ulcerans have been isolated from environmental samples. There is an inverse correlation between global warming and incidence of Buruli ulcer, possibly related to the intrinsic sensitivity of M. ulcerans to temperature, or to changes in its ecosystem. In order to improve the isolation protocols of M. ulcerans from the environment, we conducted a high-throughput phenotypic analysis of the carbon substrates metabolized by M. ulcerans and the profile obtained oriented us afterwards a bibliographic search of the main environmental sources of these substrates, towards more specific interactions of M. ulcerans with other bacteria, algae, molluscs and fungi. The results of this first work served as a basis for the development of innovative culture media which, allowed us to isolate for the first time a microcolony of M. ulcerans from feces of agouti. We also developed a method for automated reading of samples stained by Ziehl-Neelsen staining. Our thesis work has produced protocols that are intended to be implemented in African endemic countries, in order to clarify the sources and modes of transmission of M. ulcerans to populations.

The grey squirrel (Sciurus carolinensis) has wildtype and melanic (dark) colour morphs. Melanism is associated with variations in the melanocortin-1 receptor (MC1R) gene in a number of species. The MC1R protein is a G-protein coupled receptor, predominantly expressed in melanocytes, where it is a key regulator of pigment production. To investigate the genetic and molecular basis of melanism, the MC1R genes of the wildtype and melanic grey squirrel were sequenced. The wildtype (MC1R-wt) and melanic (MC1RΔ24) variants of the MC1R were then functionally characterised in a cell-based assay. The MC1R gene of the grey squirrel was found to have a 24 base pair (bp) deletion associated with melanism. The MC1R is typically activated by its agonist, the alpha-melanocyte stimulating hormone (α-MSH), which stimulates dark pigment production by raising intracellular cAMP levels. Conversely, the MC1R is inactivated by its inverse agonist, the agouti signalling protein (ASIP), which stops dark pigment production by lowering intracellular cAMP levels. To investigate the effects that the 24 bp deletion have on receptor function, MC1R-wt and MC1RΔ24 genes were transfected into HEK293 cells. Cells expressing either MC1R-wt or MC1RΔ24 were stimulated with α-MSH or ASIP and intracellular cAMP levels were measured. Unstimulated MC1RΔ24 cells showed higher basal activity than the MC1R-wt cells. Both MC1R-wt and MC1RΔ24 cells responded to α-MSH with a concentration-dependent increase in intracellular cAMP. However, while the MC1Rwt cells responded to ASIP with a concentration-dependent decrease in intracellular cAMP, MC1RΔ24 cells responded with an increase in cAMP. Melanism in the grey squirrel is associated with a 24 bp deletion in the MC1R. Cells expressing MC1RΔ24 have higher basal levels of cAMP than MC1R-wt cells. ASIP acts as an inverse agonist to the MC1R-wt but as an agonist to the MC1RΔ24. As MC1RΔ24 cells have higher levels of cAMP, and higher levels of cAMP lead to dark pigment production, the 24 bp deletion is the likely molecular cause of melanism in the grey squirrel.

Neste trabalho realizamos a análise macroscópica das estruturas do funículo umbilical e da placenta, a análise macroscópica da vascularização funicular e placentária, e a análise à microscopia de luz dos componentes funiculares da paca, procurando melhor conhecer a morfologia reprodutiva desta espécie. Para tanto, utilizamos nove pacas fêmeas, provenientes do Setor de Animais Silvestres do Departamento de Zootecnia da Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal - UNESP, nos estágios inicial, intermediário e final de prenhez, os animais tiveram o corno uterino gestante retirado cirurgicamente. Com o útero aberto identificamos as membranas fetais e fizemos a mensuração do funículo umbilical e da distância céfalo-coccígea fetal, em seguida identificamos os vasos funiculares que foram injetados com látex do tipo Neoprene corado com pigmento específico; após injeção, esses vasos foram dissecados para a visualização da disposição das artérias e veias na placenta. Três animais foram direcionados à análise microscópica do funículo umbilical que depois de colhido foi seccionado em porções proximal, intermediária e distal que foram fixadas e sofreram processamento histológico usual com posterior colorações em hematoxilina- eosina e tricromico de Masson. Constatamos nestes animais uma placenta de formato discoidal globoso e as membranas fetais constavam de cório-alantóide e âmnio. As médias das medidas dos comprimentos dos funículos umbilicais e das distâncias cefalococcígeas foram de 7,31cm e 14,5 cm respectivamente. Macroscopicamente observamos no funículo umbilical a presença de duas artérias umbilicais, uma veia umbilical, o alantóide, vasos onfalomesentéricos; microscopicamente, observamos que as artérias e veias umbilicais eram musculares, o ducto alantóide era constituído por epitélio bi-estratificado cúbico e, essas estruturas, juntamente com os vasos onfalomesentéricos estavam englobadas pela gelatina de Wharton, também se observou a presença de vasa vasorum. A dissecação dos vasos umbilicais injetados indicou que as veias se localizavam basicamente na periferia da placenta enquanto as artérias ocupavam posição centralizada. / On this research we peform the macroscopic analysis of the umbilical cord and placenta structure, the macroscopic analysis of umbilical cord and placenta valcularization, and analysis with light microscopy of umbilical cords constituents of paca, aiming to increase the knowledge about the reproductive morphology in this species. To achieve that we used nine female pacas, which came from the Wild Animal Sector of the Zootechnology Departament at the Faculty of Agrarian and Veterenary Sciences of Jaboticabal - UNESP -, in early, entermediary and late phases of pregnancy. The animals had their pregnanty uterine horn taken out on surgery. After opening the uterus, we identified the fetal membranes and measured the umbilical cord and the cephalococcyga distance. Than we identified the umbilical cords vessels with were injected with latex (Neoprene&reg;) dyed by specific pigment; after the injections, the vessels were dissected for visualization of the disposition of arteries and veins in the placenta. Three animals were carried out to microscopic analysis of the umbilical cord that , after the collect, was sectioned in proximal, intermediary and distal portions wich were set and than went to an usual histological processing with furthering colorations with hematoxilin-eosin and Masson tricome method. In these animals we noticed a discoid globular placenta, and the fetal membranes were constituted by chorion-alantois and amnion. The averages of the umbilical cords length and the crown-rump distance were 7,31 cm and 14,5 cm respectively. Macroscopically, we noticed the presence of two umbilical cord arteries, one umbilical cord vein, the allantois and onfalomesenteric vessels; microscopically, we noticed that the umbilical cord arteries and veins were muscly, the alantoic duct was formed by a cubic double layer epthelium and this sctructures, together with the onfalomezenteric vessels, were surrounded by the Wharton´s gelatin. The presence of vasa vasorum was also observed. The dissection of the injected umbilical cord vessels pointed that veins were basically placed that the placenta periphery and arteries presented a central position.

Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-05-12T15:29:10Z No. of bitstreams: 1 EricaCGP_DISSERT.pdf: 2673309 bytes, checksum: c441c049726d8b3cc5250d4dbb83b8ea (MD5) / Made available in DSpace on 2017-05-12T15:29:10Z (GMT). No. of bitstreams: 1 EricaCGP_DISSERT.pdf: 2673309 bytes, checksum: c441c049726d8b3cc5250d4dbb83b8ea (MD5) Previous issue date: 2017-02-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of the present thesis was to use the manipulation of oocytes enclosed in preantral follicles (MOIFOPA) as a tool for the female gametes rescue and conservation, from wild species agouti (Dasyprocta leporina). The dissertation was divided into two experimental phases. At first, it was performed solid surface vitrification (SSV) using different concentrations of cryoprotectant agents (CPAs) in which the effects of the 3 and 6 M concentrations of dimethylsufoxide (DMSO) and ethylene glycol (EG) were verified, as well as the association of both CPAs in the high concentration (6 M) under morphology, viability and apoptosis cell on the in situ PFs. A total of 865 PFs was analyzed before and after vitrification, it was observed an average of 80.7 ± 5.21% of morphologically normal follicles in the control group and after SSV, indifferent the CPA used, it was possible to preserve until 76.7% ± 5.4 OF PFs. At viability analysis, DMSO 3 M, DMSO 6 M, EG 3, EG 6 M (70.0%, 81.11%, 76.6% and 71.11%, respectively) presented similar values to the control group (79.0%). No apoptotic cells (TUNEL positive) were found before and after vitrification. At second, vitrification was performed using the association of CPAs, followed by xenografting of ovarian tissue in C57Bl/6 SCID Black mice. Through vaginal washing monitoring, was observed that 80% mice of the xeno-fresh group and 42% of the xeno-vitrified group returned to ovarian activity, confirmed by hormonal measures. Microscopically, primordial, primary and transitional follicles were observed in the grafts, and all had normal morphology for the species studied. However, major primordial and primary follicles were observed in transplants. The NORs revealed that after transplantation a significant reduction (1.66 ± 0.25) occurred when compared to the control groups (group fresh control: 7.19 ± 1.23 and xeno-fresh group: 9.10 ± 0.64). Apoptotic cells (TUNEL positive) were found only after transplantation of samples vitrified and the healthy follicles (TUNEL negative) observed in other groups (TUNEL negative). Thus, as the general conclusion, the use of MOIFOPA in agouti allowed the knowledge of aspects related to its reproductive morphology and physiology, enabling the germplasm conservation, with the possibility of germplasm bank formation, as the elucidation of mechanisms related to the PF survive and in vivo development / O objetivo do presente estudo foi utilizar a manipulação de oócitos inclusos em folículos ovarianos pré antrais (MOIFOPA) como ferramenta para o resgate e conservação do uso de gametas femininos de cutias (Dasyprocta leporina). A dissertação foi dividida em duas fases experimentais. Na primeira, foi realizada a vitrificação em superfície sólida (SSV) utilizando diferentes concentrações de agentes crioprotetores (ACPs), na qual foram verificados os efeitos das concentrações de 3 e 6 M de dimetilsufoxido (DMSO) e etilenoglicol (EG), bem como a associação de ambos os ACPs na concentração maior (6 M) sob a morfologia, viabilidade e apoptose celular de folículos ovarianos pré-antrais in situ (FOPAs). Um total de 865 FOPAs foi analisado antes e após a vitrificação. No grupo controle, foi observado 80,7 ± 5,21% de FOPA morfologicamente normais. Após SSV, independentemente do ACP utilizado, foram obtidos até 76,7% ± 5,4 de FOPAS. Na análise de viabilidade, DMSO 3 M, DMSO 6 M, EG 3, EG 6 M (70,0%; 81,11%; 76,6% e 71,11%; respectivamente) apresentaram valores semelhantes de FOPAS viáveis ao grupo controle (79,0%). Na segunda fase, foi realizada a SSV utilizando a associação dos ACPs (DMSO e EG), seguido do xenotransplante de tecido ovariano de cutias em camundongas C57Bl/6 SCID. Através do monitoramento do lavado vaginal, observou-se que 80% das camundongas do grupo controle e 42% do grupo vitrificado retornaram à atividade ovariana, confirmada pela dosagem hormonal. Microscopicamente, folículos primordiais, primários, transição e secundários foram observados nos enxertos, e todos tinham morfologia normal para as espécies estudadas. No entanto, os folículos primordiais e primários foram observados em maior quantidade após transplante. As Regiões organizadoras de nucléolos (NORs) revelaram que após o transplante ocorreu uma redução significativa de NORs no grupo vitrificado-xenotranplantado (1,66 ± 0,25) quando comparados aos grupos controles (grupo controle fresco: 7,19 ± 1,23; grupo controle xenotransplantado: 9,10 ± 0,64). As células apoptóticas (TUNEL positivo) foram encontradas somente após o transplante das amostras vitrificadas e folículos saudáveis foram encontrados nos outros grupos tratado (TUNEL negativo). Assim, como conclusão geral, o uso da MOIFOPA em cutias permitiu o conhecimento de aspectos relacionados a sua morfofisiologia reprodutiva, possibilitando tanto a conservação do material genético, com a possibilidade de formação de bancos de germoplasma; e ainda a elucidação dos mecanismos relacionados à sobrevivência e ao desenvolvimento dos FOPA in vivo / 2017-05-12