González Sheyla, Ibáñez Elena, Santaló Josep
Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
Stem Cell Res. 2011 Jul;7(1):54-65. doi: 10.1016/j.scr.2011.03.005. Epub 2011 Apr 3.
The first event of differentiation in mammalian embryogenesis is the segregation of the inner cell mass and trophectoderm lineages in the blastocyst. Cellular and molecular events related to this process are still a controversial issue. During the years it was thought that first allocation of blastomeres before the blastocyst stage was done in the late eight-cell stage with the formation of inner and outer cells. Lately, many studies have pointed out that individual blastomeres at the four-cell stage differ in their developmental properties according to their position within the embryo. In this report, we wanted to elucidate whether these early decisions influence the production of mouse embryonic stem cell lines, so that a selective isolation of blastomeres at the four-cell stage to derive the lines could improve the efficiency of the derivation process. Results from blastomere tracking experiments support the idea of a different developmental potential of blastomeres within the four-cell stage embryo. However, we also show a high plasticity in the developmental pattern of blastomeres once isolated from the embryo, thus making all four-cell stage blastomeres equally competent to derive ESC lines.
哺乳动物胚胎发育过程中的第一个分化事件是囊胚中内细胞团和滋养外胚层谱系的分离。与这一过程相关的细胞和分子事件仍然是一个有争议的问题。多年来，人们认为在囊胚期之前，卵裂球的首次分配是在八细胞晚期完成的，形成了内细胞和外细胞。最近，许多研究指出，四细胞期的单个卵裂球根据其在胚胎中的位置，其发育特性有所不同。在本报告中，我们想要阐明这些早期决定是否会影响小鼠胚胎干细胞系的产生，以便在四细胞期选择性分离卵裂球来获得这些细胞系能够提高分离过程的效率。卵裂球追踪实验的结果支持了四细胞期胚胎内卵裂球具有不同发育潜能的观点。然而，我们也表明，一旦从胚胎中分离出来，卵裂球的发育模式具有高度可塑性，从而使所有四细胞期卵裂球都同样有能力获得胚胎干细胞系。
