Stice S L, Robl J M
Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst 01003.
Biol Reprod. 1988 Oct;39(3):657-64. doi: 10.1095/biolreprod39.3.657.
The first six genetically verified nuclear transplant rabbits have been produced in this study. Individual eight-cell stage embryo blastomeres were transferred and fused with enucleated mature oocytes of which six full-term offspring were produced out of 164 manipulated eggs. The following efficiency rates were determined for the nuclear transplantation procedure: chromosomal removal from oocytes, 92%; fusion rate, 84%; activation rate, 46%; embryo transfer rate, 27%. Additional reasons for the low efficiency rate of nuclear transplant embryos may include limited development due to aging in recipient oocytes and asynchronous transfers of manipulated embryos to recipient females. The successful development to term may have been due to the ability of the mature oocyte to reprogram the eight-cell stage nuclei. The number of cells in blastocysts derived from isolated eight-cell blastomeres (18 +/- .08) was lower than that of nonmanipulated pronuclear (106 +/- 5.1) and nuclear transplant embryos derived from eight-cell stage nuclei (91 +/- 10.2) (p less than 0.001). This evidence along with the significant amount of nuclear swelling in nuclear transplant embryos and a delay in the time of blastocyst formation indicate that nuclear reprogramming had taken place in these embryos. Successful nuclear reprogramming indicates that serial transfers could result in the expanded multiplication of mammalian embryos.
本研究已培育出首批6只经基因验证的核移植兔。将单个八细胞期胚胎卵裂球进行移植，并与去核的成熟卵母细胞融合，在164个操作过的卵中产生了6只足月后代。确定了核移植程序的以下效率：卵母细胞染色体去除率为92%；融合率为84%；激活率为46%；胚胎移植率为27%。核移植胚胎效率低的其他原因可能包括受体卵母细胞老化导致发育受限，以及操作过的胚胎与受体雌性动物的移植不同步。成功发育至足月可能归因于成熟卵母细胞对八细胞期细胞核进行重编程的能力。源自分离的八细胞卵裂球的囊胚中的细胞数量（18±0.08）低于未操作的原核胚胎（106±5.1）和源自八细胞期细胞核的核移植胚胎（91±10.2）（p<０.001）。这一证据以及核移植胚胎中大量的核肿胀和囊胚形成时间的延迟表明这些胚胎中发生了核重编程。成功的核重编程表明连续移植可能导致哺乳动物胚胎的大量增殖。
