RESUMEN
This study was designed to examine the effect of Taxol pretreatment on vitrification of porcine oocytes matured in vitro by an open pulled straw (OPS) method. In the first experiment, the effect of Taxol pretreatment and fluorescein diacetate (FDA) staining on parthenogenetic development of oocytes was evaluated. In the second experiment, viability, microtubule organization and embryo development of oocytes were assessed after oocytes were exposed to vitrification/warming solutions or after vitrification with or without Taxol pretreatment. The results showed that Taxol pretreatment and/or FDA staining did not negatively influence the oocyte's developmental competence after parthenogenetic activation. After being exposed to vitrification/warming solutions, the survival rate (83.3%) of the oocytes was significantly (P < 0.05) reduced as compared with that in the control (100%). Vitrification/warming procedures further reduced the survival rates of oocytes regardless of oocytes being treated with (62.1%) or without (53.8%) Taxol. The proportions of oocytes with normal spindle configuration were significantly reduced after the oocytes were exposed to vitrification/warming solutions (38.5%) or after vitrification with (10.3%) or without (4.1%) Taxol pretreatment as compared with that in control (76.8%). The rates of two-cell-stage (5.6-53.2%) embryos at 48 h and blastocysts (0-3.8%) at 144 h after activation were significantly reduced after exposure to vitrification/warming solutions or after vitrification as compared with control (90.9% and 26.6% respectively). However, the proportion of vitrified oocytes developed to two-cell stage was significantly higher when oocytes were pretreated with (24.3%) than without (5.6%) Taxol. These results indicate that pretreatment of oocytes with Taxol before vitrification helps to reduce the damage induced by vitrification and is a potential way to improve the development of vitrified porcine oocytes.
