MINIMUM VOLUME VITRIFICATION?S EFFECTIVENESS IN BOVINE OOCYTES MATURED IN VITRO, EVALUATED THROUGH MORPHOLOGIC PARAMETERS

DONATO ANTONELLA; SERGIO MORADO; CYNTHIA GUTNISKY; GABRIEL DALVIT

Tucumán

Jornada; Tercera Reunión Conjunta de las Sociedades de Biología de la República Argentina; 2015

MINIMUM VOLUME VITRIFICATION?S EFFECTIVENESS IN BOVINE OOCYTES MATURED IN VITRO, EVALUATED THROUGH MORPHOLOGIC PARAMETERS Donato, A; Morado, S; Gutnysky, C; Dalvit, GBiochemistry, INITRA, FCV, UBA antonelladonato@hotmail.comThe standard method of cryopreservation of embryo and oocytes is slow freezing, although it has poor success in bovine oocyte, while the results obtained through vitrification in humans represents a possible alternative, even though is not yet commonly used in this specie and it has variable results with the current methods. The objective was to evaluate the morphology and viability of vitrified and defrosted matured bovine oocytes. We obtained oocytes-cumulus complex (COC?S) through aspiration of antral follicles of slaughtered bovine ovaries. Los COCs were matured in 199 solution with 50µg/ml of gentamicin sulphate, 5% of fetal bovine serum, 0.2 µg/ml of FSH and 2µg/ml of LH; under mineral oil at 39°C, 5% CO2 and 100% of humidity for 24hs. The matured oocytes were denuded and vitrified through Cryotech, using permeable cryoprotectants (ethylene-glycol, DMSO) osmotically active components (sucrose) and a thin film as support. They thawed using decreasing concentrations of sucrose solution in subsequent passages up to isotonic solutions. Later the oocytes were evaluated morphologically through stereomicroscope and their viability was proved through fluorochrome fluorescein diacetate technique. Until now we have vitrified/defrosted 58 matured in vitro oocytes of which 55 remained viable (94%), with normal morphology, preserving their plasmatic integrity, a reconstructed perivitelline space and a uniform cytoplasm. The results would suggest that the proposed method presents a highly effectiveness compared with slow freezing and what was been reported by the bibliography about others methods of vitrification, arising as a viable alternative for the oocytes preservation.