Lavoir M C, Rumph N, Moens A, King W A, Plante Y, Johnson W H, Ding J, Betteridge K J
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Canada.
Biol Reprod. 1997 Jan;56(1):194-9. doi: 10.1095/biolreprod56.1.194.
The pluripotency of embryonic germ cells in the mouse suggests that mitotic bovine fetal germ cells might also be a source of pluripotent cells. To investigate the pluripotency of bovine oogonia, the development in vitro of bovine embryos reconstructed by fusing oogonia with enucleated oocytes was compared with that of embryos made similarly with either blastomeres or granulosa cells. The donor cells (fresh oogonia, cryopreserved oogonia, 16- to 32-cell-stage blastomeres, or granulosa cells) were fused to the enucleated oocytes electrically. The proportions of reconstructed embryos that had cleaved at 40 h after fusion using these types of donor cells were not significantly different (37%, 33%, 56%, and 31%, respectively; p > 0.05). However, the proportions of cleaved reconstructed embryos that developed to the blastocyst stage were 9%, 13%, 36%, and 3%, respectively, significantly higher (p < or = 0.05) with blastomeres than with the other three types of donor cells. After transfer of 3 morulae and 4 blastocysts made with oogonia into three recipient heifers, embryonic and extra-embryonic tissues developed in one animal. On recovery after 43 days gestation, this conceptus was shown to be genetically identical, at 11 microsatellite loci, to the fetus that had provided the oogonia. Cytological analysis of the embryos made with oogonia at 40-44 h after fusion and at the morula and blastocyst stages revealed that aberrant cytokinesis and nucleokinesis had given rise to multinucleated, anucleate, and polyploid cells in the reconstructed embryos. It is concluded that limited pluripotency of bovine oogonia has been demonstrated, warranting further study in this area.
小鼠胚胎生殖细胞的多能性表明，有丝分裂的牛胎儿生殖细胞也可能是多能细胞的一个来源。为了研究牛卵原细胞的多能性，将卵原细胞与去核卵母细胞融合构建的牛胚胎的体外发育情况，与用卵裂球或颗粒细胞进行类似构建的胚胎的体外发育情况进行了比较。将供体细胞（新鲜卵原细胞、冷冻保存的卵原细胞、16至32细胞期的卵裂球或颗粒细胞）通过电融合的方式与去核卵母细胞融合。使用这些类型的供体细胞在融合后40小时发生卵裂的重构胚胎比例没有显著差异（分别为37%、33%、56%和31%；p>0.05）。然而，卵裂的重构胚胎发育到囊胚阶段的比例分别为9%、13%、36%和3%，卵裂球构建的胚胎显著高于其他三种供体细胞类型构建的胚胎（p≤0.05）。将用卵原细胞构建的3个桑椹胚和4个囊胚移植到3头受体小母牛体内后，有一头动物体内发育出了胚胎组织和胚外组织。在妊娠43天后回收时，这个概念胎儿在11个微卫星位点上被证明与提供卵原细胞的胎儿基因相同。对融合后40至44小时以及桑椹胚和囊胚阶段用卵原细胞构建的胚胎进行细胞学分析发现，异常的胞质分裂和核分裂导致重构胚胎中出现了多核、无核和多倍体细胞。研究得出结论，已证明牛卵原细胞具有有限的多能性，这一领域值得进一步研究。
