Sugimura Satoshi, Yokoo Masaki, Yamanaka Ken-ichi, Kawahara Manabu, Moriyasu Satoru, Wakai Takuya, Nagai Takashi, Abe Hiroyuki, Sato Eimei
Laboratory of Animal Reproduction, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.
Cell Reprogram. 2010 Aug;12(4):463-74. doi: 10.1089/cell.2009.0111.
Oxygen consumption reflects overall metabolic activity of mammalian embryos. We measured oxygen consumption in individual porcine somatic cell nuclear transfer (SCNT) and in vitro-fertilized (IVF) embryos by modified scanning electrochemical microscopy. Oxygen consumption in IVF embryos rapidly increased at day 5 of the blastocyst stage (D5BL). IVF embryos that consumed >0.81 x 10(14)/mol sec(-1) of oxygen at D5BL exhibited significantly higher hatching and hatched rates at D7BL, whereas D5BL SCNT embryos using porcine fetal fibroblasts did not show an increase in oxygen consumption until D7BL. The numbers of inner cell mass and trophectoderm (TE) cells and incidence of apoptosis did not significantly differ between IVF and SCNT embryos at D5BL. At D7BL, a significant lower number of TE cell and higher incidence of apoptosis were observed in SCNT than in IVF embryos; this significantly correlated with their oxygen consumption at D5BL. Use of cumulus cells as donor cells neutralized the low oxygen consumption in SCNT embryos at D5BL, regardless of the difference between the recipient cytoplasm and donor nucleus. Some of SCNT embryos at D7BL were retrieved the hatching completion and were improved the number of TE cell and apoptosis incidence by using cumulus cells. Thus, anomalous oxygen consumption in porcine SCNT embryos at D5BL could be sign of limited hatchability, which may be responsible for the low TE cell number and high apoptosis incidence.
氧气消耗反映了哺乳动物胚胎的整体代谢活性。我们通过改良的扫描电化学显微镜测量了单个猪体细胞核移植（SCNT）胚胎和体外受精（IVF）胚胎的氧气消耗。IVF胚胎的氧气消耗在囊胚期第5天（D5BL）迅速增加。在D5BL时消耗氧气>0.81×10(14)/mol sec(-1)的IVF胚胎在D7BL时表现出显著更高的孵化率和已孵化率，而使用猪胎儿成纤维细胞的D5BL SCNT胚胎直到D7BL才显示出氧气消耗增加。在D5BL时，IVF胚胎和SCNT胚胎的内细胞团和滋养外胚层（TE）细胞数量以及凋亡发生率没有显著差异。在D7BL时，观察到SCNT胚胎中的TE细胞数量显著低于IVF胚胎，凋亡发生率更高；这与它们在D5BL时的氧气消耗显著相关。使用卵丘细胞作为供体细胞可中和D5BL时SCNT胚胎中较低的氧气消耗，而不考虑受体细胞质和供体细胞核之间的差异。一些D7BL的SCNT胚胎实现了孵化完成，并且通过使用卵丘细胞改善了TE细胞数量和凋亡发生率。因此，猪SCNT胚胎在D5BL时异常的氧气消耗可能是孵化能力受限的迹象，这可能是导致TE细胞数量少和凋亡发生率高的原因。
