Cell biology of a specialized epithelium: regulation of the cellularizing C. elegans germline

极化细胞形状的产生对于控制细胞功能是重要的，因为它允许在该细胞内产生不同的结构域。了解这一过程对于细胞生物学至关重要，线虫已成为研究蛋白质复合体的极性产生或组装的关键模型系统。我们已经开始研究指导多核有丝分裂合体的生殖细胞(卵母细胞)有序生长和生成的分子的调控。有两个过程特别重要：侧膜的生长和连接发育中的卵母细胞和合胞体的开口(环管)的控制。要实现这种组织，需要相邻细胞之间的精细协调，细胞从头开始收缩的调节和极化结构域的产生。 在前期工作中，我们检测了两种类型的非肌肉肌球蛋白(nMy-1和nMy-2)，它们在胚系中提供细胞收缩活动。令人惊讶的是，我们的结果表明，这两个分子在指导细胞收缩方面具有拮抗作用，而不是协同作用。 该提案有三个目标。首先，我们将确定非肌肉肌球蛋白在细胞化生殖系协调发展中的空间和时间贡献。其次，我们将确定控制线虫种质中肌球蛋白收缩能力的调控途径。最后，我们将建立肌动球蛋白依赖和细胞黏附过程之间的整合机制，以建立和维持生殖系发育中的上皮细胞的图案和极性。总之，这些研究将使用模型系统中可用的强大工具来理解细胞质分裂的一个基本方面。

The generation of a polarized cell shape is important to govern cell function as it allows the production of different domains within that cell. Understanding this process is critical for cell biology, and the nematode C. elegans has become a key model system for the study of generation of polarity or assembly of protein complexes. We have begun to examine the regulation of the molecules that direct the growth and generation of an ordered progression of germ cells (oocytes) from a multinuclear mitotic syncytium. Two processes are particularly important: growth of the lateral membranes and control of the opening (ring canal) that connects the growing oocyte to the syncytium. Achieving this organization requires exquisite coordination between adjacent cells, regulation of contractility and generation of polarized domains of a cell de novo. In preliminary work, we examined two Type II non-muscle myosins (NMY-1 and NMY-2) that provide the cell contractile activity in the germline. Surprisingly, our results suggest that these two molecules have antagonistic, rather than synergistic roles in directing contractility of the cells. The proposal has three aims. First, we will determine the spatial and temporal contributions of non-muscle myosins to the coordinated development of the cellularized germline. Second, we will determine the regulatory pathways controlling myosin contractility throughout the C. elegans germline. Lastly, we will establish the mechanisms of integration between actomyosin-dependent and cell-adhesion processes in establishing and maintaining patterning and polarity in the developing epithelia of the germline. Together, these studies will use the powerful tools available in a model system to understand a fundamental aspect of cytokinesis.