Using optogenetics to link myosin patterns to contractile cell behaviors during convergent extension
Using optogenetics to link myosin patterns to contractile cell behaviors during convergent extension
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DOI：
10.1016/j.bpj.2021.06.041
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发表时间：
2021-10-05
影响因子：
3.4
通讯作者：
Kasza, Karen E.
中科院分区：
文献类型：
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作者：
Herrera-Perez, R. Marisol;Cupo, Christian;Kasza, Karen E.
肌动球蛋白收缩力的独特模式通常与发育过程中特定的上皮组织形状变化相关。例如，在果蝇体轴伸长过程中，受 Rhol 信号调节的肌球蛋白 II 定位的平面偏振模式被认为可以驱动有助于会聚延伸的细胞行为。然而，目前尚不清楚肌球蛋白模式的具体方面如何影响形态发生过程中同时发生的多种细胞行为，包括细胞嵌入、细胞形状变化和顶端细胞面积波动。在这里，我们开发了两种光遗传学工具 optoGEF 和 optoGAP，分别用于激活或停用 Rhol 信号传导。我们使用这些工具在果蝇轴伸长过程中操纵种带上皮顶端侧的肌球蛋白模式，并分析对收缩细胞行为的影响。我们发现，种带顶端表面 Rhol 信号的均匀激活或失活足以在 3-5 分钟的时间尺度上破坏细胞连接处肌球蛋白的平面极化模式，导致 optoGEF 和 optoGAP 胚胎中连接和内侧肌球蛋白模式的明显变化。这两种对 Rhol 活性的干扰都会破坏轴伸长和细胞嵌入，但对细胞面积波动和细胞堆积有明显的影响，这些波动和细胞堆积与内侧和连接肌球蛋白库的变化有关。这些研究表明，在轴伸长过程中，对 Rhol 活性的急性光遗传学扰动足以快速覆盖种带中的内源性平面偏振肌球蛋白模式。此外，我们的结果表明，Rhol 活性水平以及内侧和连接肌球蛋白之间的平衡不仅在组织细胞重排（已知直接有助于轴伸长）方面发挥着关键作用，而且在调节细胞面积波动和细胞堆积方面发挥着关键作用，这些被认为是影响组织变形和流动力学的重要因素。
Distinct patterns of actomyosin contractility are often associated with particular epithelial tissue shape changes during development. For example, a planar-polarized pattern of myosin II localization regulated by Rhol signaling during Drosophila body axis elongation is thought to drive cell behaviors that contribute to convergent extension. However, it is not well understood how specific aspects of a myosin pattern influence the multiple cell behaviors, including cell intercalation, cell shape changes, and apical cell area fluctuations, that simultaneously occur during morphogenesis. Here, we developed two optogenetic tools, optoGEF and optoGAP, to activate or deactivate Rhol signaling, respectively. We used these tools to manipulate myosin patterns at the apical side of the germband epithelium during Drosophila axis elongation and analyzed the effects on contractile cell behaviors. We show that uniform activation or inactivation of Rhol signaling across the apical surface of the germband is sufficient to disrupt the planar-polarized pattern of myosin at cell junctions on the timescale of 3-5 min, leading to distinct changes in junctional and medial myosin patterns in optoGEF and optoGAP embryos. These two perturbations to Rhol activity both disrupt axis elongation and cell intercalation but have distinct effects on cell area fluctuations and cell packings that are linked with changes in the medial and junctional myosin pools. These studies demonstrate that acute optogenetic perturbations to Rhol activity are sufficient to rapidly override the endogenous planar-polarized myosin pattern in the germband during axis elongation. Moreover, our results reveal that the levels of Rhol activity and the balance between medial and junctional myosin play key roles not only in organizing the cell rearrangements that are known to directly contribute to axis elongation but also in regulating cell area fluctuations and cell packings, which have been proposed to be important factors influencing the mechanics of tissue deformation and flow.