Edwards Robert G, Hansis Christoph
Reproductive BioMedicine Online, Duck End Farm, Dry Drayton, Cambridge CB3 8DB, UK.
Reprod Biomed Online. 2005 Aug;11(2):206-18. doi: 10.1016/s1472-6483(10)60960-1.
This brief review is devoted to the nature of early blastomere differentiation in human 4-cell embryos and its consequences for embryonic development. Precursor cells of inner cell mass, germline, and trophectoderm may be formed at this stage, the clearest evidence being available for trophectoderm. The sites of these precursor cells in the embryo could be ascertained using markers for animal and vegetal poles, observing specific cleavage planes, and assessing gene and protein expression. This opens new opportunities for studying 4-cell embryos and removing or replacing specific cells. Knowledge of the properties of individual blastomeres should help in improving assisted human reproduction, performing preimplantation genetic diagnosis, and perhaps establishing specific stem cell lines. Special attention is paid to well-characterized trophectoderm, the trophectoderm stem cell, and possible new forms of clinical application.
本简要综述致力于探讨人类4细胞胚胎中早期卵裂球分化的本质及其对胚胎发育的影响。内细胞团、生殖系和滋养外胚层的前体细胞可能在此阶段形成，关于滋养外胚层的证据最为明确。可通过使用动物极和植物极的标记、观察特定的分裂平面以及评估基因和蛋白质表达来确定这些前体细胞在胚胎中的位置。这为研究4细胞胚胎以及去除或替换特定细胞开辟了新的机会。了解单个卵裂球的特性应有助于改善人类辅助生殖、进行植入前基因诊断，并可能建立特定的干细胞系。特别关注特征明确的滋养外胚层、滋养外胚层干细胞以及可能的新临床应用形式。
