A calcium-mediated actin redistribution at egg activation in Drosophila.
A calcium-mediated actin redistribution at egg activation in Drosophila.
复制标题
果蝇卵激活时钙介导的肌动蛋白重新分布。
DOI：
10.1002/mrd.23311
复制
发表时间：
2020
影响因子：
2.5
通讯作者：
York-Andersen AH
中科院分区：
文献类型：
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作者：
York-Andersen AH
卵激活是成熟卵母细胞获得进入胚胎发育的能力的重要过程。卵激活的许多事件是保守的，包括细胞内钙的初始升高。在某些物种中，如棘皮动物和哺乳动物，肌动蛋白细胞骨架的变化发生在受精和卵子激活的时间。然而，在卵子激活过程中钙和肌动蛋白之间的相互作用仍然不清楚。在这里，我们使用成像，遗传学，药理学治疗，物理操作，以阐明钙和肌动蛋白之间的关系，在活的果蝇卵。我们发现，在卵子激活之前，肌动蛋白在脱水的成熟卵母细胞的皮质中的脊之间平滑地分布。在卵子激活的开始，我们观察到肌动蛋白随着卵子通过摄入液体而膨胀而扩散。我们表明，一个放松的肌动蛋白细胞骨架是细胞内钙离子上升启动和传播所必需的。一旦肿胀完成，钙波穿过卵子，它会导致肌动蛋白以波浪状的方式重组。在钙波之后，肌动蛋白细胞骨架在皮层具有均匀分布的病灶。总之，我们的数据表明，钙重置肌动蛋白细胞骨架在鸡蛋激活，一个模型，我们建议可能在其他物种中保存。
Egg activation is the essential process in which mature oocytes gain the competency to proceed into embryonic development. Many events of egg activation are conserved, including an initial rise of intracellular calcium. In some species, such as echinoderms and mammals, changes in the actin cytoskeleton occur around the time of fertilization and egg activation. However, the interplay between calcium and actin during egg activation remains unclear. Here, we use imaging, genetics, pharmacological treatment, and physical manipulation to elucidate the relationship between calcium and actin in living Drosophila eggs. We show that, before egg activation, actin is smoothly distributed between ridges in the cortex of the dehydrated mature oocytes. At the onset of egg activation, we observe actin spreading out as the egg swells though the intake of fluid. We show that a relaxed actin cytoskeleton is required for the intracellular rise of calcium to initiate and propagate. Once swelling is complete and the calcium wave is traversing the egg, it leads to a reorganization of actin in a wave-like manner. After the calcium wave, the actin cytoskeleton has an even distribution of foci at the cortex. Together, our data show that calcium resets the actin cytoskeleton at egg activation, a model that we propose to be likely conserved in other species.