Fertilizing Ability of Bovine Spermatozoa Following Oviduct Epithelial Cell Co-culture In Vitro

난관상피세포와 공배양한 소 정자의 체외수정능

The aim of these experiments was to investigate the effects of oviduct epithelial cells on bovine in vitro fertilization. Oviduct epithelial cell monolayers (OEC) on the 4-well dish were prepared according to general procedures. Monolayers were formed within 5days. The medium for OEC culture (TCM199 with 10% FBS) was replaced with IVF-TALP 2h before each experiment. Macromolecules/proteins from oviductal conditioned medium (OM) were recovered by ultrafiltration, which desalted and concentrated macromolecules greater than 5kDa, and this OM were added to W medium (experiment 1). The cleavage rate in OM+OEC group was significantly higher than in OM group (p〈0.01). In this experiment 2, oocytes were inseminated on OEC with sperm which had been pre-incubated with OEC for 0 or 4h before insemination. In this experiment, oocytes were exposed to sperm only 8 h for clarifying the effect. After insemination, oocytes were cultured in CRlaa. At 42 h post insemination, oocytes were denuded and examined for evidence of cleavage. The cleavage rates of oocytes which were inseminated with OEC treated sperm for 4 h were significantly higher than those of the other group (p〈0.01). In conclusion, sperm released from OEC have more fertilizing ability than those before attachment.

난관상피세포와 그 배양액에서 분비된 고분자 분획이 소정자의 수정능력에 어떠한 영향을 미치는지 알아보고자 실시한 실험에서 다음과 같은 결론을 얻었다. 1. 난관상피세포배양액으로부터 MW 5 kDa cut-off bucket을 사용하여 탈염 및 농축을 실시, 단백질/고분자분획을 회수하고 이를 체외수정용 배양액에 첨가하고 난관상피세포 monolayer와 공배양을 통해 체외수정을 실시한 결과 고분자분획첨가 및 난관상피세포 공배양(OM+OEC)군이 고분자분획첨가(OM) 군에 비하여 유의적으로 높은 분할율을 나타내었으며 난관상피 세포 공배 양(OEC)군 및 OM 군 모두 대조군에 비해서는 유의적으로 높은 분할율을 나타내었다(p〈0.01). 2. 난관상피세포와 전배양한 정자의 체외수정능을 조사한 결과 정자와 OEC를 4시간 동안 전배양한 후 체외수정한 군이 난자와 정자를 동시에 배양한 군에 비하여 유의적으로 높은 분할율을 나타내었다(p〈0.01). 이상의 결과에서 소 정자의 체외수정능은 난관 상피세포와의 접촉 및 분비액유래 고분자단백분획의 공동효과에 의한 것으로, 난관상피세포와의전배양은 체외에서 수정능획득을 유도하는 것으로 판단된다.