Estudo comparativo do processo espermatogênico e duração do ciclo do epitélio seminífero através da técnica de imunohistoquímica com Bromodeoxiuridina de três diferentes espécies de roedores da subordem Hystricomorfa: cutia (Dasyprocta leporina), paca (Cuniculus paca) e capivara (Hydrochoerus hydrochaeris)

• Ano de defesa: 2012
• Autor(a) principal: Carretta Júnior, Moacir
• Orientador(a): Paula, Tarcízio Antônio Rego de
• Banca de defesa: Costa, Deiler Sampaio , Fonseca, Cláudio César , Silva, Ita de Oliveira e
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Medicina Veterinária
• Departamento: Biotecnologia, diagnóstico e controle de doenças; Epidemiologia e controle de qualidade de prod. de
• País: BR
• Palavras-chave em Português: Roedores silvestres; Espermatogênese- imunohistoquímica
• Palavras-chave em Inglês: Wild rodents; Spermatogenesis-immunohistochemical
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1455

Among the animals of the order Rodentia, suborder Hystricomorfa, we can highlight the capybara (Hydrochoerus hydrochaeris, the agouti (Dasyprocta leporina) and paca (Cuniculus paca) because of their big corporal dimensions and high potential for commercial exploitation in order to produce excellent quality meat in the international market. These three species are currently at low risk of extinction, according to IUCN (2012), but considering the increasing destruction of natural habitat of these species, as well as poaching pressure they are subjected in nature, may occur a future decline in values in the wild population. Thus, knowledge of their reproductive biology is extremely useful in the development of assisted reproduction techniques, which is a great interest of business as well as works to promote the conservation of species. For this work we selected five specimens of adult male capybaras, from the management plan of capybaras in the campus of Universidade Federal de Viçosa; five pacas, one from the Centro de Triagem de Animais Silvestres da Universidade Federal de Viçosa and the other four commercial breeding "Um sonho a mais" - Carangola - MG, and five agoutis, from commercial breeding "Chácara Lourenço Carreta" - Santa Teresa - ES. All sources of animals were following the law of the Brazilian Institute of Environment and Natural Resources (IBAMA). The animals were restrained physically and chemically for the application of intratesticular immunomarker (5- bromodeoxyuridine) as well as procedures of hemicastration. All procedures in animals were previously approved by the Ethics Committee for animal use at the Universidade Federal de Viçosa. After hemicastration, the testes collected were fixed in Karnovsky solution and distinct fragments were subjected to histological processing in glycol methacrylate resin, for histological and morphometric parameters of the testis, and paraffin wax, which are mounted on slides electrically charged for the detection by monoclonal antibody and revealed by staining system biotin-streptavidin, by BrdU staining kit. It was observed that the proportion of body mass allocated in testis (GSI) was 0.11% in capybara, 0.27% and 0.28% in agouti in pacas. The proportion allocated to the mediastinum testis and testicular albuginea was approximately 12% in capybaras, agoutis 8% and 6% in pacas, and the value for the latter two are below the majority mammals already studied. pacas, and the value for the latter two are below the majority mammals already studied. The volumetric proportion of seminiferous tubules showed high values in agouti (93%) and pacas (91%), while the capybara showed one of the lowest values previously studied (50%) The total length of the seminiferous tubules of testes per gram of testis in capybaras (12.46 m / g) is within the range described to mammals, while the agouti and agouti showed values much above this range 26.7 and (35.5 m / g respectively) Tubulossomatic Index (TSI) was 0,06% in capybaras, agoutis, and 0.23% in 0.24 in pacas, and these values confirm the mating behavior described for these species. It was observed that the three species exhibit the pattern I organization of the components of the intertubular space proposed by Fawcett (1973 ), with the agouti and agouti within the same sub-pattern described by Paula (1999 ) for Cavioidea superfamily, the capybara showed na unique sub-pattern. The values of volumetric proportion of Leydig cell in agouti (2%) and pacas (2.6%) are close to that described for various other rodents, while capybara distinguished by an extremely higher value (35%). The Leydigossomatic index (LSI) of the agouti (0.005%) and paca (0.007%) are below the other rodents already studied, while the capybara has values similar to these. The population of Leydig cells per gram of testis in capybaras was found the largest ( 126 million cells / g) while the values of agouti (16 million) and pacas (35 million) are below. The cell population of the different germ cells of capybaras, agoutis and pacas, in cross sections of seminiferous tubule in stage 1 of the seminiferum epithelium cycle (ESC), were within the range observed in the superfamily Cavioidea. The support capabilities of all germ cells by Sertoli cells on the agouti (22 germ cells: one Sertoli cell) and the agouti (24 germ cells: one Sertoli cell) are higher than other rodents and mostly of the various species of domestic mammals already studied, indicating a high efficiency of these cells in this species. The capybara (11 germ cell: one Sertoli cell) had values similar to other rodents already studieds. The process of spermatogonial mitoses show a loss of 93.23% in capybaras, 87,51% in agoutis and 86.7% in pacas, if they have six generations of meiotic spermatogonia. The meiotic yield and overall yield of spermatogenesis showed a total loss of the theoretically expected value respectively from 92.5% and 47.25% in capybaras, 30% and 91.2% in agoutis and 38.5% and 93% in pacas, being within the range observed for the other mammals. An ESC observed in capybaras (10.39 days) and pacas (8.57 days) is in the range observed for several rodent species already studied, while the agouti had the shortest duration ever reported for a rodent (5.86 days). The sperm reserves per gram of testis is 105 million sperm in capybaras, 290 million in pacas and 674 million in the agouti. The sperm production per gram of testis in agoutis (115 million) was far superior to many species of wild and domestic mammals already studied, including the value observed in pacas (34 million) and capybaras (10 million).