细胞分裂是生物体生长和繁殖的基础，细胞分裂失控常常导致特定细胞的异生、增生甚至肿瘤的出现。在细胞分裂过程中，胞质分裂发生在特定的位置和时间，使母代细胞物理上分为两个子代细胞，并决定了子代细胞内遗传物质、细胞内容物的正确含量，是维持细胞稳态的关键。胞质分裂的核心驱动因子是小G蛋白Rho家族成员RhoA。本课题将结合现代光遗传学技术TULIP系统和定量荧光活体细胞成像技术，通过在线虫早期胚胎细胞中的细胞膜不同区域或细胞周期不同阶段光招募RhoA激活因子ECT-2 GEF活性，研究在胞质分裂期间RhoA被激活的时空调控分子机制，以及RhoA下游与收缩环组装相关各效应因子的活性与细胞周期的相关性。本课题还将通过光遗传学技术和体外重建实验，研究centralspindlin复合体CYK-4亚基对RhoA活性的正反馈调节机制。

Cytokinesis is a fundamental biological process in which the parent cell physically separates and sequesters the duplicated genetic materials into two daughter cells. Cytokinesis starts just after anaphase onset with cleavage furrow formation. Proper completion of cytokinesis involves exquisite temporal and spatial coordination between the actin and microtubule cytoskeletal systems. Failure of cytokinesis causes polyploidy which has been associated with cancer. The small GTPase RhoA is the master regulator of cytokinesis, which is activated by centralspindlin and its GEF (guanine nucleotide exchange factor) ECT-2..This study will use an optogenetic-based technology called TULIPs (tunable, light-controlled interacting protein tags), allowing light-directed control of protein localization and protein-protein interactions, combining with live-cell imaging microscopy, to dissect spatial-temporal regulation of RhoA during cytokinesis in C. elegance early embryonic cells. In addition, this study will investigate roles of centralspindlin subunit CYK-4 on positive feedback regulation pathways of RhoA during cytokinesis.