Research focused on female gamete vitrification has increased attention to develop a reliable cryopreservation method to preserve immature equine oocytes. Despite the intensive implementation of biotechnological procedures for horse breeding, vitrification of immature equine cumulus-oocyte complexes (COCs) remain to be clearly elucidated. We aimed to determine the relative transcript level of target genes Bone morphogenetic protein 15 (BMP15); Bcl-2-associated X protein (BAX); and Caspase 3 (CASP3) in equine COCs prior to and after vitrification. Ovarian follicles were aspirated from ovaries collected from an abattoir. A total of 240 COCs were collected and distributed into vitrified COCs (VIT, n=120) and non-vitrified (Non-VIT, n=120) groups. Then, COCs were preserved and relative transcript expressions of BMP15, BAX, CASP3 were measured and normalized against GAPDH performed by qRT-PCR. In addition, 38 COCs were evaluated to assess chromatin configuration of germinal vesicl e stage prior and after vitrification by exposure to 10 μg/ml of bisbenzimide. A difference was observed in the COCs’ mRNA level of abundance for the BAX gene between the VIT (2.05 ± 0.47) and (0.85 ± 0.08) Non-VIT groups. There was no difference in mRNA relative transcript level of CASP3 and BMP15 in Non-VIT (0.63 ± 0.20 and 1.55 ± 0.73, respectively) compared to VIT (0.64 ± 0.01 and 2.84 ± 2.20, respectively) equine COCs. All COCs where considered at immature stage of development even though COCs in Non-VIT group showed higher condensed chromatin configuration compared to VIT (100% vs 60.7%, respectively). We demonstrate that BMP15 and CASP3 are detected in VIT and Non-VIT immature COCs. In conclusion, BAX is expressed highly in vitrified immature equine COCs and indicates that activation of apoptosis signaling cascades in cells exposed to vitrification.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.