Initiation of gastrulation in the mouse embryo is preceded by an apparent shift in the orientation of the anterior-posterior axis
Initiation of gastrulation in the mouse embryo is preceded by an apparent shift in the orientation of the anterior-posterior axis
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DOI：
10.1016/j.cub.2004.01.030
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发表时间：
2004-02-03
期刊：
影响因子：
9.2
通讯作者：
Collignon, J
中科院分区：
文献类型：
--
作者：
Perea-Gomez, A;Camus, A;Collignon, J
背景资料：一般认为，前内脏内胚层（AVE）细胞在胚胎第5.5天从远端向近端的迁移打破了小鼠胚胎的径向对称性，标志着前部，并在E6.5时在相对侧形成原始条纹。原肠胚小鼠胚胎的横切面符合椭圆的轮廓，原始条纹位于其长轴的一端。如何建立的前-后（AP）极性涉及到的postimplantation胚胎的形态是，然而，uncleared.Results：prestreak E6.0胚胎的横切面也揭示了一个椭圆形的轮廓，但AP轴，定义的分子标记，往往是垂直于椭圆形的长轴。随后，AP轴和长轴的相对取向发生变化，使得当原肠胚形成开始时，它们更接近平行，尽管不是完全对齐。其结果是，大多数胚胎短暂失去其双边对称性时，原始条纹开始形成在epiblast.Conclusions：AP轴的方向的变化是唯一明显的，结果从整个epiblast，在细胞迁移不参加戏剧性的重塑。这些结果揭示了小鼠原肠胚中迄今为止未被怀疑的调节和可塑性水平。
Background: It is generally assumed that the migration of anterior visceral endoderm (AVE) cells from a distal to a proximal position at embryonic day (E)5.5 breaks the radial symmetry of the mouse embryo, marks anterior, and conditions the formation of the primitive streak on the opposite side at E6.5. Transverse sections of a gastrulating mouse embryo fit within the outline of an ellipse, with the primitive streak positioned at one end of its long axis. How the establishment of anterior-posterior (AP) polarity relates to the morphology of the postimplantation embryo is, however, unclear.Results: Transverse sections of prestreak E6.0 embryos also reveal an elliptical outline, but the AP axis, defined by molecular markers, tends to be perpendicular to the long axis of the ellipse. Subsequently, the relative orientations of the AP axis and of the long axis change so that when gastrulation begins, they are closer to being parallel, albeit not exactly aligned. As a result, most embryos briefly lose their bilateral symmetry when the primitive streak starts forming in the epiblast.Conclusions: The change in the orientation of the AP axis is only apparent and results from a dramatic remodeling of the whole epiblast, in which cell migrations take no part. These results reveal a level of regulation and plasticity so far unsuspected in the mouse gastrula.