The Effects of Duration of the In Vitro Maturation Process on the Maturation Level and Apoptosis of Kacang Goat

Abstract

The success of in vitro fertilization and embryo culture depends on the success of in vitro maturation. However, standard culture conditions usually increase reactive oxygen species (ROS), which have been implicated as a major cause for reduced embryonic development. It is well-known that higher than physiological levels of ROS trigger granulosa cell apoptosis and thereby reduce the transfer of nutrients and survival factors to oocytes, leading to apoptosis. This study aimed to determine the optimal timing of oocyte maturation and its relationship to DNA fragmentation. Ovaries were collected from a slaughterhouse and the follicles aspirated. The cumulus oocyte complexes were divided into groups and transferred to a maturation medium, where they were maintained for 18 hours (P1), 22 hours (P2) and 24 hours (P3) to evaluated maturation rate. Matured oocytes were characterized as oocytes that reached the MII stage. Matured oocytes were counterstained with terminal deoxynucleotidyl transferase nick-end labelling (TUNEL). The results showed that the maturity rate of Kacang goat oocytes reached 46% after 18 hours, 77% after 22 hours, and 63% after 24 hours. However, the results showed that the expression of DNA fragmentation in P2 (2.4 ± 0.89) were significantly different from P1 (5.4 ± 2.61) and P3 (9.0 ± 2.12). In conclusion, the optimal timing of in vitro maturation of Kacang goat oocytes is 22 hours.