THE 1ST CLEAVAGE PLANE AND THE EMBRYONIC AXIS ARE DETERMINED BY SEPARATE MECHANISMS IN XENOPUS-LAEVIS .2. EXPERIMENTAL DISSOCIATION BY LATERAL COMPRESSION OF THE EGG
THE 1ST CLEAVAGE PLANE AND THE EMBRYONIC AXIS ARE DETERMINED BY SEPARATE MECHANISMS IN XENOPUS-LAEVIS .2. EXPERIMENTAL DISSOCIATION BY LATERAL COMPRESSION OF THE EGG
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DOI：
10.1016/0012-1606(88)90267-9
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发表时间：
1988-07-01
影响因子：
2.7
通讯作者：
VINCENT, JP
中科院分区：
文献类型：
--
作者：
BLACK, SD;VINCENT, JP
在非洲爪蟾卵中，精子进入子午线（SEP子午线）、皮质下旋转方向和第一卵裂沟已被用于预测胚胎双侧对称平面的位置，其准确度各不相同。我们在这里表明，通过侧向压缩改变未卵裂卵的形状以可重复的方式破坏了这些地形关系中的一些。识别胚胎背中线的神经沟通常形成于压缩卵的两个狭窄末端中的任一个，而与SEP子午线的位置无关，而第一卵裂沟将压缩卵在其较短的维度上分开，而与SEP子午线的位置无关。因此，SEP子午线、卵裂平面和胚胎双侧平面的位置可以彼此完全分离。相反，皮质下旋转的方向通常与压迫平面平行，并在所有情况下预测神经沟的位置。由于皮质下旋转的方向和平面的双边对称性仍然相关的条件下的压缩，我们得出结论，皮质下旋转轴规格的过程中的关键的早期步骤。
In eggs of Xenopus laevis, the meridian of sperm entry (SEP meridian), the direction of subcortical rotation, and the first cleavage furrow have been used to predict, with varying degrees of accuracy, the position of the plane of bilateral symmetry of the embryo. We show here that altering the shape of the uncleaved egg by lateral compression disrupts some of these topographical relationships in a reproducible way. The neural groove, which identifies the embryonic dorsal midline, usually forms at either of the two narrow ends of the compressed egg, regardless of the position of the SEP meridian, whereas the first cleavage furrow divides the compressed egg across its shorter dimension, regardless of the position of the SEP meridian. Thus the positions of the SEP meridian, the cleavage plane, and the embryonic bilateral plane can be completely uncoupled from each other. In contrast, the direction of subcortical rotation is usually parallel to the plane of compression and predicts the position of the neural groove in all cases. Since the direction of subcortical rotation and the plane of bilateral symmetry still correlate under conditions of compression, we conclude that subcortical rotation is the crucial early step in the process of axis specification.