These study was to investigate the in vitro fertilization and viability of fresh and vitrified oocytes. Also, the developmental capacity of IVF and intracytoplasmic sperm injection (ICSI) oocytes were investigated. Then vitrification was performed with the use of 20% ethylene glycol + 20% DMSO + 0.5 M sucrose + 10% FCS + TCM-199 medium. Vitrification immature oocytes are cultured in vitrification solution for 10 min afterwards transferred to expose at room temperature for 5 min. and transferred to the ice water for 5 min. The oocytes were sealed in a 1.0 mm straw and placed in a LN2 container. Frozen oocytes were rapidly thawed in a water bath at 30～35℃, and then placed in TCM-199 medium containing 0.5 M sucrose for 5 min each, respectively, at 38℃. After being washed for 2～3 times, using fresh medium the oocytes were cultured in TCM-199 medium supplemented with 5% FCS at 38℃ in 5% CO2 and air. The normal morphology of fresh and vitrified-thawed oocytes were 87.1±2.1% and 54.8±2.5%, respectively. The viability rates of fresh and vitrified-thawed oocytes were 70.0±2.2% and 41.9±2.6%, respectively. Viability rates of vitrified-thawed oocytes were lower than that of fresh follicular oocytes (p<0.05). The in vitro maturation rates of fresh and vitrified oocytes were 45.1±3.6% and 28.9±4.4%, respectively. The IVF rates of fresh follicular and vitrified-thawed oocytes were 34.0±2.2% and 20.2±2.6%, respectively. The in vitro maturation and fertilization rates of vitrified-thawed oocytes were lower than those of the fresh follicular oocytes (p<0.05). A total of 350 oocytes were fixed and stained after co-incubation with spermatozoa, of which 88 had identifiable nuclear material. After IVF for 20 hrs, 25.1±3.4% of the oocytes found to have been penetrated by spermatozoas. Oocytes were fixed and stained after ICSI, and 105 oocytes contained identifiable nuclear material. After IVF and ICSI for 20 hrs, 34.3±3.4% and 59.0±2.0% of the oocytes were found to have been penetrated by spermatozoas. The developmental rates upon ICSI were significantly higher than those of the IVF method (p<0.05).

ABSTRACT   INTRODUCTION   MATERIALS AND METHODS    Recovery and Culture of Oocytes    Vitrification and Thawing of Oocytes    IVF Procedure    ICSI Procedure    Assessment of Survival and Developmental Rate    Statistical Analysis   RESULTS    Viability of Fresh and Vitrified-Thawed Oocytes    IVM and IVF of Fresh and Vitrified Oocytes    In Vitro Development of Oocytes Following IVF and ICSI   DISCUSSION   REFERENCES

• Ji-Hoon Park(College of Veterinary Medicine, Chungnam National University)
• Young-Ho Chung(Dept. of Companion Animal and Animal Resourses Science, Joongbu University)
• Sang Keun Kim(College of Veterinary Medicine, Chungnam National University) Corresponding author