Oct-4 mRNA and protein expression during human preimplantation development
Oct-4 mRNA and protein expression during human preimplantation development
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DOI：
10.1093/molehr/gah155
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发表时间：
2005-03-01
影响因子：
4
通讯作者：
Van Steirteghem, A
中科院分区：
文献类型：
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作者：
Cauffman, G;Van de Velde, H;Van Steirteghem, A
转录因子OCT-4由于其在全能性/多能性中的作用而被认为是控制哺乳动物早期胚胎发育的关键因子。在人类植入前胚胎中，OCT-4研究仅限于对异常发育胚胎的RNA分析。本研究全面研究了OCT-4在整个人类着床前发育过程中的表达模式。通过单细胞RT-PCR或间接免疫细胞化学方法在36个不同成熟度的单个卵母细胞和112个正常发育的植入前胚胎中的单卵裂球、桑椹胚、囊胚或内细胞团（ICM）和滋养外胚层（TE）样品水平上检测表达。卵母细胞和卵裂期胚胎显示了一个变量OCT-4的表达模式，伴随着纯细胞质定位的蛋白质。在压实过程中，表达的变异性消失，表明胚胎OCT-4表达，并且蛋白质出现在细胞核中，表明生物活性。在胚泡中，OCT-4转录物和蛋白质存在于ICM和TE中。在蛋白质水平上，OCT-4剪接变异体在同一细胞内的空间表达模式不同，这可能赋予它们不同的功能特性。由于OCT-4转录物也存在于各种分化的细胞中，OCT-4转录物或蛋白质的存在可能不足以鉴定人类中的未分化细胞系。此外，我们建议检查OCT-4蛋白在细胞内的定位，而不是寻找转录本的存在和/或数量。
The transcription factor OCT-4 is regarded as a critical factor in controlling mammalian early embryonic development because of its role in toti-/pluripotency. In human preimplantation embryos, OCT-4 studies are limited to RNA analysis of abnormally developing embryos. This study thoroughly investigated the expression pattern of OCT-4 throughout the human preimplantation development. Expression was examined by single-cell RT-PCR or indirect immunocytochemistry in 36 single oocytes of various maturity and 112 normally developing preimplantation embryos at the level of single blastomeres, morulas, blastocysts, or inner cell mass (ICM) and trophectoderm (TE) samples. Oocytes and cleavage stage embryos revealed a variable OCT-4 expression pattern, concomitant with a pure cytoplasmic localization of the protein. During compaction, the variability in expression faded away indicating embryonic OCT-4 expression and the protein appeared in the nucleus implying biological activity. In blastocysts, OCT-4 transcripts and proteins were present in the ICM and the TE. At protein level, blastocysts displayed different spatial expression patterns within a cell for the splice variants of OCT-4, which may endow them with different functional properties. As OCT-4 transcripts were also found in various differentiated cells, the presence of OCT-4 transcripts or proteins may not be sufficient for identifying undifferentiated cell lines in humans. Further, we suggest to examine the localization of OCT-4 proteins within a cell rather than to look for the presence and/or amount of transcripts.