Hansis Christoph, Grifo James A, Tang YaXu, Krey Lewis C
Program for In Vitro Fertilization, Reproductive Surgery and Infertility, New York University School of Medicine, 660 First Avenue, 5th floor, New York, NY 10016, USA.
Reprod Biomed Online. 2002 Sep-Oct;5(2):156-61. doi: 10.1016/s1472-6483(10)61618-5.
In human embryos, blastomeres differentiate into trophectoderm (TE) cells and inner cell mass (ICM) cells of blastocysts. Although morphologically indistinguishable, blastomeres at early cleavage stages are likely to undergo changes on a molecular level that make them destined to become ICM or TE cells. While the transcription factor Oct-4 might serve as a marker for totipotent ICM cells, human chorionic gonadotrophin might be used as the equivalent for TE cells. This study reports a reverse transcription-polymerase chain reaction procedure to assess human beta-HCG mRNA concentrations as well as ploidy in individual blastomeres from normally and abnormally fertilized human embryos. beta-HCG mRNA was detected in both euploid and aneuploid cells and in oocytes. Surprisingly, beta-LH mRNA was also detected in some euploid blastomeres. In regard to preimplantation genetic diagnosis, assessment of expression levels of beta-HCG and Oct-4 mRNA in individual biopsied cells might serve as a tool to identify embryogenic blastomeres in combination with testing for chromosome and single gene abnormalities.
在人类胚胎中，卵裂球分化为囊胚的滋养外胚层（TE）细胞和内细胞团（ICM）细胞。尽管在形态上无法区分，但早期卵裂阶段的卵裂球在分子水平上可能会发生变化，从而决定它们将成为ICM细胞或TE细胞。转录因子Oct-4可能作为全能ICM细胞的标志物，而人绒毛膜促性腺激素可能相当于TE细胞的标志物。本研究报告了一种逆转录-聚合酶链反应程序，用于评估正常和异常受精的人类胚胎中单个卵裂球的人β-HCG mRNA浓度以及倍性。在整倍体和非整倍体细胞以及卵母细胞中均检测到β-HCG mRNA。令人惊讶的是，在一些整倍体卵裂球中也检测到了β-LH mRNA。关于植入前遗传学诊断，评估单个活检细胞中β-HCG和Oct-4 mRNA的表达水平，可能与检测染色体和单基因异常相结合，作为识别胚胎源性卵裂球的一种工具。
