Effects of gas conditions, time of medium change, and ratio of medium to embryo on in vitro development of horse oocytes fertilized by intracytoplasmic sperm injection

• Published in: Theriogenology 2003-03, Vol.59 (5), p.1219-1229
• Main Authors: Choi, Young-Ho, Love, Charles C., Varner, Dickson D., Love, Linda B., Hinrichs, Katrin
• Format: Article
• Language: English
• Subjects: Animals; Carbon Dioxide - physiology; Culture Media; Embryonic and Fetal Development - physiology; Female; Fertilization; Horse; Horses - embryology; Intracytoplasmic sperm injection; Male; Nitrogen - physiology; Oocyte; Oocytes - physiology; Oxygen - physiology; Random Allocation; Sperm Injections, Intracytoplasmic - methods; Sperm Injections, Intracytoplasmic - veterinary; Zygote
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/S0093-691X(02)01164-0

This study was conducted to evaluate the effects of two different gas conditions (5% CO 2 in air or 5% CO 2, 5% O 2, 90% N 2, mixed gas), time of medium change (Day 3 or 4) and ratio of medium to embryo (2, 5 or 10 μl per presumptive zygote) on the development of horse oocytes fertilized by intracytoplasmic sperm injection and cultured in G1.2/2.2 medium. Oocytes from slaughterhouse-derived ovaries were matured in vitro for 24 h and fertilized by injection of frozen–thawed sperm using micromanipulation with a Piezo drill. Presumptive zygotes were randomly assigned to 5% CO 2 in air or mixed gas and fixed after 96 h of culture. Cleavage rates between two gas conditions were similar (67 and 63%), but the mean nucleus number of embryos in the mixed gas treatment was significantly ( P