A dissection of the mechanisms generating and stabilizing polarity in mouse 8- and 16-cell blastomeres: the role of cytoskeletal elements.
A dissection of the mechanisms generating and stabilizing polarity in mouse 8- and 16-cell blastomeres: the role of cytoskeletal elements.
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剖析小鼠 8 细胞和 16 细胞卵裂球中产生和稳定极性的机制：细胞骨架元素的作用。
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
B. Maro
中科院分区：
文献类型：
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作者：
M. Johnson;B. Maro
从分离的1/4或1/8的卵裂球分别培养出1/4或1/8的8细胞或16细胞的卵裂球，培养至9h。通过FITC-ConA的结合和微绒毛的分布来评估其表面极性的出现和方向，以及通过细胞质肌动蛋白、网织蛋白和与膜细胞器的溶酶体/酸性囊泡部分相关的100kD抗原的分布来评估它们的细胞质极性。研究了紫杉醇、诺可达唑、细胞松弛素D或诺可达唑+细胞松驰素D在孵育不同时间段对细胞的极性的影响。任何处理都不能阻止8-细胞卵裂球表面极性的发展和稳定，只有联合使用CCD和诺可达唑才能显着影响表面极性的发生。然而，经过一些处理后，表面极的形状和位置发生了改变。在微管抑制剂存在的情况下，表面极延伸到细胞表面的较大区域，而暴露在电荷耦合器件中会导致极不与细胞之间的接触点相反。与表面极性相反，细胞质极性的发展被微管和微丝抑制药物抑制，这也迅速逆转了它。在极型16细胞卵裂球中，表面极性受影响的方式与8细胞型卵裂球相似，只有细胞松弛素D和诺可达唑的联合使用才有显著影响。包括细胞松弛素D在内的所有药物处理几乎都能完全抑制极16细胞卵裂球中的网状蛋白极化。溶酶体抗原在16细胞阶段的局部浓度只有在诺考达唑和细胞松弛素D持续存在的情况下才能降低，但一旦建立，任何药物都不能明显逆转。然而，溶酶体抗原在极化细胞的基底区的定位似乎在任何药物存在的情况下都没有发生。这些实验中揭示的表面和细胞质极性的分离使我们得出结论：要么表面极性是细胞质极性组织的先决条件，并通过细胞骨架调节后者，要么表面和细胞质极性以平行但分离的机制发展。
Pairs of 8-cell or 16-cell blastomeres were cultured for up to 9 h after their formation from isolated 1/4 or 1/8 blastomeres respectively. Blastomeres were examined for the incidence and orientation of their surface polarity, as assessed by binding of FITC-Con A and by distribution of microvilli, and of their cytoplasmic polarity, as assessed by distribution of cytoplasmic actin, clathrin and a 100 kD antigen associated with the lysosomal/acid vesicle fraction of membranous organelles. The effect on polarity of incubating the pairs of cells in taxol, nocodazole, cytochalasin D or in a combination of nocodazole plus cytochalasin D for different parts of the incubation period was examined. Neither the development nor the stability of the surface polarity in 8-cell blastomeres was blocked by any treatment and only the use of CCD in combination with nocodazole affected the incidence of surface polarity appreciably. However, with some treatments, the form and position of the surface poles were modified. In the presence of microtubule inhibitors surface poles extended over a larger area of the cell surface, while exposure to CCD led to poles that were not opposite to the contact point between cells. In contrast to surface polarity, the development of cytoplasmic polarity was suppressed by both microtubule- and microfilament-inhibiting drugs, which also reversed it rapidly. In polar 16-cell blastomeres surface polarity was influenced in a similar manner to that of 8-cell blastomeres, only the combined use of cytochalasin D and nocodazole having any major effect. Polarization of clathrin in polar 16-cell blastomeres was inhibited almost completely by all drug treatments applied including cytochalasin D. The focal concentration of lysosomal antigen that occurs during the 16-cell stage was reduced only in the continuous presence of nocodazole plus cytochalasin D, but once established was not reversed appreciably by any drug. However, the localization of the lysosomal antigen to the basal region of polarized cells did not seem to occur in the presence of any drug. The dissociation of surface and cytoplasmic polarity revealed in these experiments leads us to conclude that either surface polarity is a prerequisite for the organization of cytoplasmic polarity, and mediates the latter via the cytoskeleton, or surface and cytoplasmic polarity develop by parallel but separate mechanisms.