Contact-independent polarization of the cell surface and cortex of free sea urchin blastomeres.
Contact-independent polarization of the cell surface and cortex of free sea urchin blastomeres.
复制标题
游离海胆卵裂球细胞表面和皮层的接触无关极化。
DOI：
10.1016/0012-1606(88)90209-6
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发表时间：
1988
影响因子：
2.7
通讯作者：
Schroeder,TE
中科院分区：
文献类型：
--
作者：
Schroeder,TE
在一个正常的，完整的海胆胚胎卵裂球的结构极化，使所有的微绒毛和皮质的“色素颗粒”位于顶面面对透明层，并没有从基底外侧表面面对相邻的卵裂球和内部的胚胎腔。为了测试细胞间接触和透明层在建立这种卵裂球极性的过程中的作用，这两个因素进行了实验消除;四个物种的海胆卵在受精后不久被剥除新生的透明层，然后在无钙的人工海水中培养，以防止随后的细胞间粘附和接触。这种游离卵裂球分裂正常，并仍发展出类似于完整胚胎中相应卵裂球的微绒毛和色素颗粒的极化分布。这些结果表明，极化的过程是固有的个别卵裂球（自极化），既不细胞间的接触，也不粘附的微绒毛的透明层是必要的。极化模式和分裂周期在时间和空间上的精确重合进一步表明，在细胞分裂、卵裂球极化之间保持着一种机械联系，而且可能也是动物-植物轴的一个可遗传的组成部分。
In a normal, intact sea urchin embryo blastomeres are structurally polarized so that all microvilli and cortical “pigment granules” are situated at the apical surfaces facing the hyaline layer and are absent from basolateral surfaces facing adjacent blastomeres and the internal embryonic cavity. To test the roles of intercellular contacts and the hyaline layer in the process of establishing this blastomere polarity, these two factors were experimentally eliminated; sea urchin eggs of four species were denuded of the nascent hyaline layer soon after fertilization and then cultured in calcium-free artificial seawater to prevent subsequent intercellular adhesion and contact. Such free blastomeres divided normally and still developed polarized distributions of microvilli and pigment granules resembling those of the corresponding blastomeres in intact embryos. These results indicate that the process of polarization is intrinsic to individual blastomeres (self-polarization) and that neither intercellular contacts nor adhesion of microvilli to the hyaline layer is necessary. The precise temporal and spatial coincidence of the patterns of polarization and the division cycles further suggests that a mechanistic link is maintained among cell division, blastomere polarization, and probably also a heritable component of the animal-vegetal axis.