Teses em Biotecnologia (Doutorado) - PPGBIOTEC/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/7377
O Doutorado em Biotecnologia teve início em 2011 e funciona no Programa de Pós-Graduação em Biotecnologia (PPGBIOTEC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).
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Navegando Teses em Biotecnologia (Doutorado) - PPGBIOTEC/ICB por Autor "BRITO, Danielle Cristina Calado de"
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Item Acesso aberto (Open Access) Vitrificação de tecido ovariano de gata doméstica (Felis catus): um modelo para a preservação da fertilidade em felinos silvestres(Universidade Federal do Pará, 2016-09-06) BRITO, Danielle Cristina Calado de; SANTOS, Regiane Rodrigues dos; http://lattes.cnpq.br/0500967766886604; PIECZARKA, Julio Cesar; http://lattes.cnpq.br/6644368250823351The aim o the present thesis was to develop an efficient vitrification protocol of the ovarian tissue from domestic cat (Felis catus). This study was divided: Phase I: Effect of different basis media during the vitrification of cat ovarian tissue; Phase II: Effect of different sugars (extracellular cryoprotectants) and the vitrification technique for the vitrification of feline ovarian tissue. In phase I, the morphology of preantral follicles was similar (p > 0.05) to fresh control when RPMI-1640 was used as basis medium for vitrification. RPMI-1640 does not contain phenol red, which was found to enhance ethylene glycol (EG) toxicity during vitrification. In phase 2, the percentage of morphologically normal preantral follicles was similar (p > 0.05) to fresh control only when the vitrification medium contained 0.1 or 0.5 M trehalose, instead of sucrose or raffinose at same concentrations. Furthermore, based on parameters such as morphology, cell proliferation and thickness of collagen fibers, it is possibe to assume that efficient vitrification of feline ovarian tissue can be performed by combining trehalose with EG, with or without dimethylsulfoxide (DMSO), applying the solid-surface vitrification (SSV) or ovarian tissue cryosystem (OTC) method. Although vitrification with OTC in the presence of EG did not differ from the other treatments, this protocol presented the highest percentages of preserved preantral follicles (56%), being similar to control (64%). Additionally, no effect on gene regulation was observed after vitrification when apoptosis markers (BAX – protein X associated to Bcl-2), endoplasmic reticulum (ER) stress (ER protein 29 – ERP29), water channels proteins like aquaporins 3 and 9 (AQP3 and AQP9), the membrane ABC transporters ABCB1 and ABCG2, except when the SSV method was applied using only EG as cryoprotectant followed by seven days in vitro culture, where ERP29 up-regulation (ER stress) and AQP9 down-regulation (impaired water transport) were observed. Based on this, it can be concluded that to efficiently preserve feline ovarian tissue, is is necessary the use of a vitrification protocol free of phenol red, supplemented with trehalose, as extracellular cryoprotectant, and EG alone or in combination with DMSO, as intracellular cryoprotectants. Both open (SSV) and closed (OTC) systems are equaly efficient to maintain follicular survival during the vitrification procedure.