Effect of Ovary Transport Temperature on Survivability and Maturation Rate of Canine Oocytes

This study examined the viability of canine oocytes following storage at 4 or 38$^{\circ}C$ for 5 h. Cumulus intact oocytes were collected from domestic dog following ovariohysterectomy at local veterinary clinics. In Exp I, the oocytes that collected from ovary transport different temperatures (4 or 38$^{\circ}C$) for 5 h, were cultured for (24 or 48 h). Survivability of oocytes judged by morphological appearance and PI (propidium iodide) staining. The survival rates at 4$^{\circ}C$ ovary transport group showed significantly lower than control group (0%; 0/129 vs. 72.9%; 129/177) 48 h after culture (P<0.05). In Exp II, to assess nuclear maturation of control group oocytes (ovary transported at 38$^{\circ}C$) after in vitro cultured for 24, 48 or 96 h. After 24 h and 48 h of culture, the metaphase I to metaphase II stages (MI to MII) was 8.3% (6/72) and 8.9% (9/101), and which was not increased at 96h (9.5%; 8/84). These results show that canine oocytes remarkably sensitive to low temperature and the percentage of oocytes reaching MI to MII did not increase 96 h after culture.

개 난소 수송온도에 따른 미성숙 난자의 생존율과 핵 성숙율

본 연구는 개 난소의 수송온도가 난자의 생존률에 미치는 영향과 체외성숙 배양시 성숙률에 미치는 영향에 대하여 검토하였다. 1. 개 난소를 4$^{\circ}C$와 38$^{\circ}C$에 저장 후 5시간 내로 연구실로 운반한 난소에서 채취한 난자를 체외배양 하여 생존율을 조사한 결과 체외배양 24시간째 13.2%(15/114), 77.8%(105/135)의 생존율을 보였으며, 48시간째는 0% (0/129), 72.9% (129/177) 의 생존율을 나타내어 38$^{\circ}C$에 수송한 난소에서 채취한 난자가 4$^{\circ}C$에 수송한 난소에서 채취한 난자보다 유의적으로 높은 생존율을 보였다. 2. 체외성숙 배양 24, 48, 96 시간 체외배양하여 핵 성숙율을 확인한 결과 MI∼MII까지의 성숙율이 8.3% (6/72), 8.9% (9/101), 9.5% (8/84)로 체외배양 시간을 96시간까지 연장하여도 성숙률이 증가하지 않았다.