A genetic approach to discover novel regulators of microtubule behaviour

我们研究的目标是了解像有丝分裂纺锤体这样的微观结构是如何在活细胞中组装的。就像大多数复杂的4维生物过程一样，对纺锤体组装的完整理解将取决于对单个组件的属性的了解以及对它们的组装是如何在活细胞中协调的认识。我们使用线虫秀丽线虫来研究这个问题，因为微管结构在第一次细胞分裂中迅速组装和拆解，可能需要许多调控分子提供指令。了解微管对细胞分裂的重要性，以及它们对这种分子指令的敏感性，也许最好的证据是许多抗癌药物针对微管聚合物(例如紫杉醇和长春花碱)。然而，我们并不完全了解微管生长和分解是如何在细胞内调节的。通过结合使用抑制子遗传学和RNA介导的干扰，我们将在线虫的第一次细胞分裂中寻找微管过程所需的基因。这将通过关注两条不同的调节途径来完成。第一条途径涉及中心体蛋白质磷酸化的调节(一种使细胞中大多数微管核化的结构)。我们希望识别执行指示微管“建立有丝分裂纺锤体”的信号指令的蛋白质。第二个项目将专注于鉴定一种基因，由于其突变的表型，在早期受精卵为第一次有丝分裂做准备时，很可能需要协调微管的行为。这些途径结合在一起，为发现微管动力学的新调节因素提供了一个理想的起点，并可能进一步加深我们对高等真核生物细胞分裂的理解。

The goal of our research is to understand how microscopic structures such as the mitotic spindle assemble in living cells.  Like most complex 4-dimensional biological processes, a complete understanding of spindle assembly will depend on knowledge of the properties of individual components as well as an appreciation for how their assembly is orchestrated in living cells.  We use the nematode Caenorhabditis elegans to study this problem because microtubule structures are assembled and disassembled rapidly in the first cell division, and many regulatory molecules are likely required to provide the instructions.  The importance of microtubules to cell division, and their sensitivity to such molecular instruction, is perhaps best evidenced by the fact that many anti-cancer drugs target the microtubule polymer (e.g. Taxol and Vinblastine).  However, we do not have a complete understanding of how microtubule growth and disassembly is regulated within the cell.  By using a combination of suppressor genetics and RNA-mediated interference, we will search for genes that are required for microtubule processes in the first cell division of C. elegans.  This will be accomplished by focusing on two distinct pathways of regulation.  The first involves the regulation of protein phosphorylation at the centrosome (a structure that nucleates the majority of microtubules in the cell).  We hope to identify proteins that are carrying out the orders of a signal that instructs microtubules to "build a mitotic spindle".  The second project will focus on the identification of a gene that, because of its mutant phenotype, is likely required to coordinate microtubule behaviour at a time when the early fertilized egg prepares for the first mitotic division.  Together, these pathways provide an ideal starting point to discover novel regulators of microtubule dynamics and will likely further our understanding of cell division in higher eukaryotes.