maturaÇÃo nuclear in vitro e morte celular por apoptose em oÓcitos de caprinos nos perÍodos seco e chuvoso

This study aimed to determine the in vitro nuclear maturation and cell death by apoptosis in goat oocytes. The ovaries of goats were collected during the dry (October-March) and rainy (April-September) seasons in slaughterhouses and transported to the Laboratory of Reproductive Biotechniques of UFRPE. Twelve repetitions were performed and cumulus oophorus were collected from follicles of 2-6 mm diameter using the technique of "slicing" and selected based on morphology. The experiment contained two groups: Group-1 (not matured), evaluated immediately after collection, and Group-2 (matured in vitro), assessed after 24 hours of maturation in a CO2 incubator, in which 25 oocytes per drop were placed in alkaline maturation (MBM). After collecting the oocytes from G-1 and G-2, the quality was determined by testing the enzyme activity of caspases and DNA fragmentation (TUNEL), using PhiPhiLux-G1D2 reagent, and in group G-2 the quality was only determined after nuclear maturation. During nuclear maturation stages, germinal vesicle, germinal vesicle breakdown and metaphase I and II were evaluated and no significant differences were found (P> 0.05). There was also no significant difference (P> 0.05) in enzymes activity of caspase and DNA fragmentation of oocytes matured and not matured in vitro. Based on the data obtained, it was concluded that rainy and dry seasons have no effect on in vitro nuclear maturation and apoptosis of goat oocytes.