Cell polarity in C.elegans

本研究旨在了解微管在秀丽隐杆线虫早期胚胎极性形成和传递中的作用。在秀丽隐杆线虫的第一次细胞分裂过程中，皮层分为两个区域，由不同的PAR蛋白定义。这些PAR皮质结构域的形成被认为是由精子中心体的元素驱动的，并定义了胚胎的前后轴。随后，这些PAR蛋白通过调节细胞骨架的性质来介导不对称细胞分裂的形成。在这些不对称事件中，突出的是形成不对称纺锤体，导致两个不同大小的细胞。我们既不了解中心体/微管如何驱动皮质结构域的形成，也不了解这些皮质结构域如何调节微管的动力学以驱动不对称细胞分裂。本文提出：1）利用中心体突变体和激光消融来确定中心体组分在建立细胞极性中的作用; 2）发展分析微管在细胞不对称分裂过程中动态变化的技术。我们将结合联合收割机这种分析与激光消融微管，试图确定力产生所需的不对称细胞分裂的微管。

This proposal is concerned with understanding the role of microtubules in the establishment and transduction of polarity in the early C.elegans embryo. During the first cell division of C.elegans the cortex divides into two domains, defined by different PAR proteins. The formation of these PAR cortical domains is thought to be driven by elements of the sperm centrosome and defines the anterior-posterior axis of the embryo. Subsequently these PAR proteins mediate the formation of an asymmetric cell division, by modulating the properties of the cytoskeleton. Prominent among these asymmetric events is the formation of an asymmetric spindle, leading to two cells of different sizes. We understand neither how centrosomes/microtubules drive the formation of the cortical domains, nor how these cortical domains modulate the dynamics of the microtubules to drive asymmetric cell division. Here we propose 1) To use both mutants in centrosomes and laser ablation to define the role of centrosome components in establishing cell polarity 2) To develop techniques to analyze the changing dynamics of microtubules during asymmetric cell division. We will combine this analysis with laser ablation of microtubules in attempt to identify the force generating microtubules required for asymmetric cell division.