Influence of cell polarity on early development of the sea urchin embryo.
Influence of cell polarity on early development of the sea urchin embryo.
复制标题
DOI：
10.1002/dvdy.24337
复制
发表时间：
2015-12
期刊：
影响因子：
--
通讯作者：
Burgess DR
中科院分区：
文献类型：
--
作者：
Moorhouse KS;Gudejko HF;McDougall A;Burgess DR
细胞极性的建立和维持对正常胚胎发育至关重要。以前，人们认为棘皮动物胚胎在16细胞阶段的第一次不对称分裂之前保持相对非极化。在这里，我们分析了细胞极性调节剂，PAR复合物蛋白的作用，以及它们在早期发育中的破坏如何影响后来的发育里程碑。我们发现，PAR 6，aPKC和CDC 42本地化的顶端皮层早在2细胞阶段，并通过原肠胚阶段保留这种本地化。有趣的是，PAR1也通过原肠胚阶段与这些顶端标志物共定位。此外，发现PAR 1与aPKC复合，但不与PAR 6复合。PAR 6、aPKC和CDC 42通过组装的肌球蛋白锚定在皮质肌动蛋白细胞骨架中。此外，组装的肌球蛋白被认为是必要的，以保持适当的PAR6定位通过随后的裂解分裂。干扰肌球蛋白组装阻止胚胎达到囊胚期，而肌动蛋白或微管的短暂破坏没有这种效果。这些观察结果表明，早期胚胎中极性的破坏可能对胚胎达到发育后期关键阶段的能力产生重大影响。
Establishment and maintenance of cell polarity is critical for normal embryonic development. Previously, it was thought that the echinoderm embryo remained relatively unpolarized until the first asymmetric division at the 16 cell stage. Here we analyzed roles of the cell polarity regulators, the PAR complex proteins, and how their disruption in early development affects later developmental milestones. We found that PAR6, aPKC and CDC42 localize to the apical cortex as early as the 2 cell stage and that this localization is retained through the gastrula stage. Interestingly, PAR1 also colocalizes with these apical markers through the gastrula stage. Additionally, PAR1 was found to be in complex with aPKC, but not PAR6. PAR6, aPKC, and CDC42 are anchored in the cortical actin cytoskeleton by assembled myosin. Furthermore, assembled myosin was found to be necessary to maintain proper PAR6 localization through subsequent cleavage divisions. Interference with myosin assembly prevented the embryos from reaching the blastula stage, while transient disruptions of either actin or microtubules did not have this effect. These observations suggest that disruptions of the polarity in the early embryo can have a significant impact on the ability of the embryo to reach later critical stages in development.