Hoppe P C, Illmensee K
Proc Natl Acad Sci U S A. 1982 Mar;79(6):1912-6. doi: 10.1073/pnas.79.6.1912.
Diploid parthenogenetically activated oocytes were obtained after gonadotropin-induced ovulation of virgin females of the LT/Sv (LT) inbred mouse strain. These oocytes cleave spontaneously and develop into blastocysts which implant in the uterus but die within a few days. We examined the developmental potential of nuclei from parthenogenetic embryos after transplantation into fertilized eggs. The inner cell mass (ICM) and trophectoderm (TE) of LT parthenogenetic blastocysts were mechanically isolated and dissociated into single cells. Their nuclei were then injected into fertilized C57BL/6J eggs from which the male and female pronuclei were removed. Of 94 eggs injected with TE cell nuclei, 4 embryos developed to the morula stage; all 4 showed abnormalities and subsequently became arrested in development. Enzyme analysis of these embryos revealed that TE cell nuclei could neither independently initiate or support preimplantation development. However, of 54 eggs injected with nuclei from ICM cells, 3 morulae and 3 blastocysts developed and enzyme analyses of them confirmed that the preimplantation development of 2 embryos was supported by transplanted parthenogenetic nuclei. In another experimental series, 3 morulae and 4 blastocysts developed from 107 eggs injected with ICM nuclei and were transferred to uteri of foster mothers to ascertain their postimplantation development. Four female offspring were born and all of them showed a diploid karyotype and expressed enzyme activity of only the LT genotype. One female proved to be fertile and transmitted the parthenogenetic genome to the next generation. These results demonstrate that the nucleus from LT parthenogenetic blastocysts contains a complete genome necessary to support development of an adult mouse. Therefore, the early postimplantation death of parthenogenetic embryos does not seem to be related to an aberrant genotype but rather to undefined mechanisms associated with fertilization and normal morphogenetic processes.
通过对LT/Sv（LT）近交系小鼠处女雌鼠进行促性腺激素诱导排卵后，获得了二倍体孤雌生殖激活的卵母细胞。这些卵母细胞能自发分裂并发育成囊胚，囊胚可植入子宫，但在几天内死亡。我们研究了孤雌胚胎细胞核移植到受精卵后的发育潜能。将LT孤雌囊胚的内细胞团（ICM）和滋养外胚层（TE）机械分离并解离成单细胞。然后将它们的细胞核注射到去除了雄原核和雌原核的C57BL/6J受精卵中。在注射了TE细胞核的94个卵中，有4个胚胎发育到桑葚胚阶段；这4个胚胎均表现出异常，随后发育停滞。对这些胚胎的酶分析表明，TE细胞核既不能独立启动也不能支持着床前发育。然而，在注射了ICM细胞核的54个卵中，有3个桑葚胚和3个囊胚发育，对它们的酶分析证实，2个胚胎的着床前发育得到了移植的孤雌细胞核的支持。在另一个实验系列中，从注射了ICM细胞核的107个卵中发育出3个桑葚胚和4个囊胚，并将它们移植到代孕母亲的子宫中以确定其着床后发育情况。产下了4只雌性后代，它们均表现出二倍体核型，且仅表达LT基因型的酶活性。有1只雌性后代被证明具有生育能力，并将孤雌基因组传递给了下一代。这些结果表明，LT孤雌囊胚的细胞核包含支持成年小鼠发育所需的完整基因组。因此，孤雌胚胎着床后早期死亡似乎与异常基因型无关，而与受精和正常形态发生过程相关的未明确机制有关。
