Developmental control of spindle positioning in embryos

胚胎中纺锤体定位的发育控制

• 批准号: 7198116
• 负责人: LESILEE S. ROSE
• 金额: $ 25.07万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7198116
• 关键词: Address; Amino Acid Sequence; Anaphase; Animal Model; Biological Assay; Biological Models; Caenorhabditis elegans; Cell Polarity; Co-Immunoprecipitations; Cues; Data; Daughter; Depth; Development; Developmental Process; Disease; Drosophila genus; Embryo; Event; G-Protein Signaling Pathway; GTP-Binding Protein Regulators; GTP-Binding Proteins; Genes; Genetic; Goals; Human; Immunoprecipitation; Inherited; Laboratories; Lead; Localized; Longitudinal Studies; Malignant Neoplasms; Mammals; Mediating; Membrane; Mitotic spindle; Molecular; Movement; Nuclear; Numbers; Organism; Pathway interactions; Pattern; Peptide Sequence Determination; Phenotype; Play; Positioning Attribute; Proteins; Role; Rotation; Signal Transduction; Testing; Time; Transgenes; Transgenic Organisms; Two-Hybrid System Techniques; Vertebrates; Video Microscopy; Work; Yeasts; base; gene cloning; genetic analysis; human JTB protein; insight; mutant; polarized cell; receptor; response

DESCRIPTION (provided by applicant): Proper positioning of the mitotic spindle is essential for a number of developmental processes, including asymmetric divisions in which a polarized cell divides to produce daughters with different fates. This project addresses the mechanisms by which the conserved PAR polarity proteins and a downstream intermediate, LET-99, regulate spindle position during asymmetric divisions in the model organism Caenorhabditis elegans. Several hypotheses about LET-99 function will be tested. In Aim 1, the genetic pathway by which the PAR proteins localize LET-99 in a cortical band will be determined by examining LET-99 localization in mutant backgrounds. In addition, the regions of the LET-99 protein that are necessary and sufficient for cortical and asymmetric localization will be identified using transgenes. In Aim 2, the hypothesis that the cortical LET-99 band controls spindle positioning will be tested by time-lapse video microscopy of mutants with altered LET-99 distributions. Aim 3 will test the hypothesis that LET-99 antagonizes the G protein signaling pathway that functions in spindle positioning. Genetic interactions will be examined and possible associations between LET-99 and components of the G protein pathway will be assayed using co-immunoprecipitations and two-hybrid assays. In Aim 4, the hypothesis that the spn-2 gene acts with LET-99 to antagonize G protein signaling will be tested. In the long term, these studies will lead to an in-depth understanding of the molecular mechanisms that coordinate polarity and spindle orientation. Asymmetric divisions are important to the development of all multcellular organisms, and the PAR proteins are conserved in many organisms, including humans. Thus, insights gained from this work will be of wide relevance and could also aid in the understanding of developmental abnormalities that lead to cancer or other disorders.

描述（由申请人提供）：有丝分裂纺锤体的正确定位对于许多发育过程至关重要，包括不对称分裂，其中极化细胞分裂产生具有不同命运的子细胞。该项目解决了保守的PAR极性蛋白和下游中间体，LET-99，调节纺锤体的位置在模式生物秀丽隐杆线虫的不对称分裂过程中的机制。关于LET-99功能的几个假设将被检验。在目的1中，通过PAR蛋白定位LET-99在皮质带中的遗传途径将通过检查突变背景中的LET-99定位来确定。此外，将使用转基因识别对于皮质和不对称定位所必需且足够的LET-99蛋白区域。在目标2中，皮质LET-99带控制纺锤体定位的假设将通过改变LET-99分布的突变体的延时视频显微镜进行测试。目的3将测试LET-99拮抗G蛋白信号通路的假设，该信号通路在纺锤体定位中起作用。将检查遗传相互作用，并将使用免疫共沉淀和双杂交试验测定LET-99和G蛋白途径组分之间的可能关联。在目的4中，将测试spn-2基因与LET-99一起拮抗G蛋白信号传导的假设。从长远来看，这些研究将导致对协调极性和纺锤体取向的分子机制的深入理解。不对称分裂对所有多细胞生物体的发育都很重要，PAR蛋白在许多生物体中是保守的，包括人类。因此，从这项工作中获得的见解将具有广泛的相关性，也有助于理解导致癌症或其他疾病的发育异常。