Oocyte maturation with linoleic acid preserves sperm binding and fusion patterns after vitrification

RIOS, G.; BUSCHIAZZO, J.; ORESTI, G.M.; ALBERIO, R.

Mar del Plata

Congreso; LI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2015

Binding and fusion of sperm to zona pellucida (ZP) free bovine oocytes matured with linoleic acid (18:2n6) at different concentrations were evaluated. In addition, the effect of cryopreservation on fertilization and caspase activation were analyzed. Oocytes were assigned to 3 experimental groups: matured without 18:2n6 (control), matured with 43µM 18:2n6 and matured with 100µM 18:2n6. Fresh and vitrified oocytes were fertilized in vitro after ZP removal. Activation of caspases in situ was evaluated using a specific inhibitor (VAD-FMK-FITC). Vitrified oocytes matured in 43µM 18:2n6 showed similar levels of activated caspases with respect to control oocytes, while incubation with 100µM 18:2n6 increased by 3-fold caspase activation. Incubation with 18:2n6 increased sperm binding and fusion in fresh oocytes. Only oocytes matured in 43µM 18:2n6 preserved a pattern of biding and fusion similar to non-vitrified control oocytes. Maturation with 18:2n6 (43µM) does not affect oocyte apoptotic status and preserves membrane functionality and ability to decondense sperm nucleus for fertilization.