PORCINE OOCYTES MEIOTIC PROGRESSION AND ITS RELATION WITH REACTIVE OXYGEN SPECIES PRODUCTION AND MITOCHONDRIAL ACTIVITY DURING IN VITRO MADURATION

AGUSTINA CAMPORINO; FIAMMA SENGIALI; PABLO CETICA; SERGIO MORADO

Congreso; Reunión Conjunta de Sociedades Biomédicas; 2023

During in vitro maduration (IVM) a series of modifications take place in the oocyte, which lead to its developmental competence and involve a variation in reactive oxygen species (ROS) production. The aim of our study was to evaluate meiotic progression, ROS production and mitochondrial activity in porcine oocytes during IVM. Cumulus-oocyte complexes (COCs) obtained by aspiration of antral follicles from ovaries of slaughtered gilts were incubated in 199 medium supplemented with 50 μg/ml gentamicin sulfate, 10% (v/v) porcine follicular fluid, 0.57 mM cysteine, 0.5 μg/ml FSH and 0.5 μg/ml of LH at 39ºC, 5% CO2 in a humidified atmosphere for 44h. At 0, 12, 24, 36 and 44h, cohorts of COCs were recovered from the IVM medium and denuded with a glass Pasteur pipette. Using epifluorescence microscopy, meiotic progression was assessed by Hoechst 33342, ROS production by DCH2FDA, active mitochondria by MitoTracker Green and internal mitochondrial membrane potential by JC-1 stain. Digital microphotographs were obtained and processed using IMAGE J software to calculate oocyte fluorescence intensity. Between 0 and 12h oocytes progressed from germinal vesicle stage to germinal vesicle breakdown, observing a concomitant decrease in ROS production and a significant increase in active mitochondria and mitochondrial membrane potential (p