Progress in polarity of the mammalian embryo Development
哺乳动物胚胎发育极性的研究进展

Mammalian embryo development is regulatived ——— it is flexible and responsive to experimental intervention. This flexibility could be explained if embryogenesis were originally completely unbiased and disordered; order and determination of cells only arise later. Alternatively, regulative behaviour could be consistent with the embryo having some order or bias from the very beginning, with inflexibility and cell determination increasing steadily over time. Recent evidence supports the second view and indicates that the sequence and the orientations of cell divisions affect the polarity of Pre-implantation embryo development.