In Vitro Development and Survival Following Cryopreservation of Bovine Embryos according to Ovary Transport Temperature

난소 수송 온도에 따른 소 체외 수정란의 발육 및 동결-융해 후의 생존성

  • Cho S.R. (Animal Genetic Resources Station, NLRI, RDA) ;
  • Choi S.H. (Animal Genetic Resources Station, NLRI, RDA) ;
  • Kim H.J. (Animal Genetic Resources Station, NLRI, RDA) ;
  • Choe C.Y. (Animal Genetic Resources Station, NLRI, RDA) ;
  • Jin H.J. (Animal Genetic Resources Station, NLRI, RDA) ;
  • Son D.S. (Animal Genetic Resources Station, NLRI, RDA)
  • 조상래 (농촌진흥청 축산연구소 가축유전자원시험장) ;
  • 최선호 (농촌진흥청 축산연구소 가축유전자원시험장) ;
  • 김현종 (농촌진흥청 축산연구소 가축유전자원시험장) ;
  • 최창용 (농촌진흥청 축산연구소 가축유전자원시험장) ;
  • 진현주 (농촌진흥청 축산연구소 가축유전자원시험장) ;
  • 손동수 (농촌진흥청 축산연구소 가축유전자원시험장)
  • Published : 2006.06.01

Abstract

The present study was carried out to investigate in vitro development and post-thawed survivability of bovine embryos according to different ovary transport temperatures. Bovine ovaries were collected at a local slaughterhouse and were transported at 4 different temperature categories to laboratory: $7{\sim}10^{\circ}C\;(T1),\;11{\sim}17^{\circ}C\;(T2),\;18{\sim}25^{\circ}C\;(T3)$ and above $26^{\circ}C$ (control group). The cumulus-oocyte-complexes aspirated from ovaries were in vitro matured, fertilized and cultured. The rates of maturation (to metaphase II), cleavage and development to blastocysts were compared among treatment groups. Furthermore, frozen-thawed blastocysts were in vitro cultured to compare the survivability among groups. The maturation rates in the T1, T2 and T3 groups ($60.0{\sim}68.2%$) were significantly lower than that in the control group (81.8%, p<0.05). The cleavage rates in the T1 and T2 groups (52.6 and 54.5%) were significantly lower than that in the control group (83.6%, p<0.05). However, there was no difference in the development rate to blastocysts among all groups ($27.9{\sim}33.0%$, p>0.05). The survivability of frozen-thawed embryos was significantly lower in the T1 group (46.2%) than those in the T2, T3 and control groups ($68.8{\sim}7.13%$, p<0.05). In conclusion, the results suggest that ovary transport temperature at $26^{\circ}C$ may be optimal for the better in vitro development and the survival of frozen-thawed embryos produced in vitro Furthermore, exposure of ovary to temperature below $10^{\circ}C$ during transport may significantly decrease both in vitro development and survivability of frozen-thawed blastocysts.

본 연구는 도축되는 소 난소의 효율적인 이용을 위해서 도축장으로부터 실험실로 운반되는 난소 수송 온도에 따른 체외 수정란 생산 효율을 조사하고자 실시되었다. 도축장의 HACCP 적용으로 도축장 출입이 불가능하므로 위탁하여 난소를 공급받게 되어 취급자의 부주의로 적절한 온도 유지가 되지 않는 경우가 많다. 특히 겨울철에는 더 많은 주의가 필요하다. 따라서 본 실험에서는 겨울철 난소수송 온도에 따라서 4처리 그룹, 즉 $7{\sim}10^{\circ}C$ (T1), $11{\sim}17^{\circ}C$(T2), $18{\sim}25^{\circ}C$(T3) 그리고 $26^{\circ}C$ 이상인 경우를 control 그룹으로 구분하였다. 회수된 난포란을 체외 성숙, 수정 및 배양을 실시하여 처리 그룹간 체외 성숙율, 분할율, 배반포 발달율 및 배반포의 세포수를 비교하였으며, 동결-융해한 배 반포에 대해서도 생존성에 대하여 비교하였다. 실험 결과를 요약하면 다음과 같다. 1. 회수된 난포란을 22시간 동안 체외 성숙시켰을 때 수정 적기인 제2감수분열 중기에 도달한 비율은 $T1{\sim}T3$ 그룹에서 $60.0{\sim}68.2%$의 비율로 나타났으나, control 그룹에서는 81.8%로 다른 처리군에 비해서 유의적으로(p<0.05) 높은 결과를 보였다. 2. 체외 수정 후 48 시간에 확인한 분할율은 control 그룹이 83.6%로서 T3 그룹과는 유의적인 차이 가 없었으나, T1(52.6%) 또는 T2 그룹(54.5%)에 비해서 유의적인(p<0.05) 차이를 보였다. 수정 후 168시간과 192시간까지의 배반포 생산율은 처리군간 유의적인 차이를 보이지 않았다. 3. 생산된 blastocysts를 동결-융해하여 수정란의 생존성을 확인한 결과, T1 그룹이 46.2%로서 다른 처리군($68.8{\sim}73.1%$)에 비해서 유의적으로(p<0.05) 낮은 생존율을 나타내었다. 따라서 본 실험의 연구 결과를 살펴볼 때 도축되는 소 난소의 수송 온도는 $26^{\circ}C$ 이상을 온도를 유지하는 것이 저온에 의한 난포란 손상을 최소화하여 체외 발달율 및 동결-융해 후 생존율을 높여, 궁극적으로 수정란이식 산업과 생명 공학 분야의 실험의 효율을 증진시키는데 기여할 수 있을 것으로 사료된다.

Keywords

References

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