Cheong H T, Takahashi Y, Kanagawa H
Department of Theriogenology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Jpn J Vet Res. 1992 Dec;40(4):149-59.
The present study was conducted to examine the development of nuclear transplant embryos produced by transplanting nuclei to either oocytes or zygotes in the mouse. Metaphase II oocytes and one-cell zygotes were enucleated and fused with transferred nuclei from late two-, four- and eight-cell stage embryos. Enucleation of metaphase oocytes was achieved using the interference microscope without staining. Fusion and oocyte activation were performed by means of electric fields. Similar development rates to the blastocyst stage were obtained from enucleated oocytes (28.0%) and zygotes (30.9%) reconstituted with nuclei from late two-cell embryos. Cleavage and blastocoele formation of reconstituted embryos occurred at around the same time as observed in the control embryos, with some exceptions. After transfer to recipient females, live young were obtained from both reconstituted oocytes (9.1%) and zygotes (11.5%) that received a nucleus from late two-cell embryos. The results indicate that enucleated zygotes as well as oocytes can support development to term of nuclei introduced from late two-cell embryos in which activation of the embryonic genome has occurred, which may be a result of the reprogramming of the donor nucleus.
本研究旨在检测通过将细胞核移植到小鼠的卵母细胞或受精卵中所产生的核移植胚胎的发育情况。将处于减数分裂中期II的卵母细胞和单细胞受精卵去核，并与来自晚期二细胞、四细胞和八细胞阶段胚胎的移植细胞核融合。使用干涉显微镜在不染色的情况下实现中期卵母细胞的去核。通过电场进行融合和卵母细胞激活。用来自晚期二细胞胚胎的细胞核重构的去核卵母细胞（28.0%）和受精卵（30.9%）发育到囊胚阶段的比率相似。重构胚胎的卵裂和囊胚腔形成与对照胚胎大致在同一时间发生，但有一些例外。将重构胚胎移植到受体雌性小鼠体内后，接受来自晚期二细胞胚胎细胞核的重构卵母细胞（9.1%）和受精卵（11.5%）均获得了活的幼崽。结果表明，去核受精卵以及卵母细胞能够支持已发生胚胎基因组激活的晚期二细胞胚胎所导入细胞核发育至足月，这可能是供体细胞核重编程的结果。
