논문 상세보기
pp.263-272
생쥐의 난자는 특별한 첨가물이나 난구세포 없이 체외 배양해도 성숙율이 높은 반면 돼지 난자의 체외성숙율은 매우 낮다. 본 연구는 이러한 차이의 원인을 연구하기 위하여 생쥐와 돼지 난자의 에너지 생성에 관여하는 유전자인 malate dehydrogenase(Mor2)의 기능을 RNAi를 이용하여 비교 분석하였다. 생쥐와 돼지 각각의 Mor2 double-stranded RNA(dsRNA)를 제작하고, 생쥐는 난구세포를 제거한 미성숙(GV) 난자의 세포질에
Contrast to mouse where its in vitro maturation rates are high without specific supplements or presence of the cumulus cells, there are some species, such as porcine, where its in vitro oocyte maturation rates are still very low. This comparative study was conducted to investigate the role of malate dehydrogenase(Mor2) during oocyte maturation by RNAi in the mouse and porcine. The Mor2 double-stranded RNA(dsRNA) was prepared speciesspecifically and microinjected into the cytoplasm of denuded germinal vesicle(GV) oocytes. Oocytes were cultured for 48 h(porcine) and 16 h(mouse) in M199 with 10% porcine follicular fluid, pyruvate, p-FSH, EGF, cystein, and estradiol-. We measured changes in oocyte morphology, maturation rates and mRNA levels after Mor2 RNAi. We confirmed gene sequence-specific knock down of Mor2 mRNA in both species after Mor2 RNAi. In contrast to our previous finding that mMor2 RNAi resulted in GV arrest in the mouse, we found that pMor2 RNAi resulted in MI arrest in denuded porcine oocytes(58%), but developed to MII(84.4%) in COCs. To determine whether this difference between mouse and porcine RNAi is due to differences in culture media, we cultured mouse oocytes in the M199 media for 16 h after mMor2 RNAi. Mouse oocytes were developed to MII stage(62%) and there was no statistical difference compared to that of non-injected(76.8%) and buffer-injected(73.3%) control groups. Therefore, we concluded that the mouse and porcine oocytes are having different metabolic systems in relation to malate dehydrogenase for oocyte maturation. This could be a basis for differences in maturation rates in vitro in two species. Further scrutinized studies on the metabolic pathways would led us in finding better culture system to improve oocyte maturation rates in vitro, especially in more challenging species like the porcine.
