The development potential of parthenogenetically derived cells in chimeric mouse embryos: implications for action of imprinted genes.
The development potential of parthenogenetically derived cells in chimeric mouse embryos: implications for action of imprinted genes.
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发表时间：
1988-09
期刊：
影响因子：
4.6
通讯作者：
Hugh J. Clarke;Susannah Varmuza;V. Prideaux;Janet Rossant
中科院分区：
文献类型：
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作者：
Hugh J. Clarke;Susannah Varmuza;V. Prideaux;Janet Rossant
小鼠的孤雌胚胎在植入后不久死亡，并且特征性地含有发育不良的胚外组织。为了研究孤雌生殖异常发育的基础，我们将它们与正常胚胎结合以产生嵌合体，并检查孤雌生殖衍生细胞在植入前和植入后早期发育过程中的分布。孤雌生殖胚胎来源于带有大插入物的转基因小鼠系，这使得这些细胞可以使用原位杂交在组织切片中鉴定。在囊胚阶段，孤雌胚胎为嵌合体的滋养外胚层（TE）和内细胞团（ICM）提供细胞。然而，到6.5天，在几乎每个胚胎中，在TE的胚外滋养层组织中未检测到孤雌生殖衍生的细胞。与此相反，孤雌生殖衍生的细胞可以有助于所有后代的ICM的6.5和7.5天的嵌合体，包括胚外内脏和壁内胚层。在6.5-7.5天的胚胎外胚层嵌合的程度的定量分析表明，孤雌生殖衍生的细胞可以作为广泛的正常细胞的贡献。这些结果表明，正常的滋养层发育需要在胚胎发生的6.5天之前从父系遗传的基因组中表达基因。然而，ICM谱系的组织显然可以独立于父本基因组发育至少到胚胎发生的7.5天。这些结果与其他结果的比较表明，印记基因的影响表现在不同的时间和不同的组织在发展过程中。
Parthenogenetic embryos of mice die shortly after implantation and characteristically contain poorly developed extraembryonic tissue. To investigate the basis of the abnormal development of parthenotes, we combined them with normal embryos to produce chimeras and examined the distribution of the parthenogenetically derived cells during preimplantation and early postimplantation development. The parthenogenetic embryos were derived from a transgenic mouse line bearing a large insert, which allowed these cells to be identified in histological sections using in situ hybridization. At the blastocyst stage, the parthenogenetic embryos contributed cells to the trophectoderm (TE) and inner cell mass (ICM) of chimeras. By 6.5 days, however, in almost every embryo, parthenogenetically derived cells were not detected in the extraembryonic trophoblast tissue descended from the TE. In contrast, parthenogenetically derived cells could contribute to all descendants of the ICM of 6.5-and 7.5-day chimeras, including the extraembryonic visceral and parietal endoderm. Quantitative analysis of the degree of chimerism in the embryonic ectoderm at 6.5-7.5 days indicated that parthenogenetically derived cells could contribute as extensively as normal cells. These results indicate that normal trophoblast development requires gene expression from the paternally inherited genome before 6.5 days of embryogenesis. Tissues of the ICM lineage, however, apparently can develop independently of the paternal genome at least to 7.5 days of embryogenesis. Comparison of these results with those of others suggests that the influence of imprinted genes is manifested at different times and in a variety of tissues during development.