Identification and Characterization of Helix Loop Helix Transcription Factors in Caenorhabditis Elegans

脊椎动物的正常发育需要在分子水平上对事件进行精心的安排。因此，调节基因表达的因子在细胞规范、形态发生和生长等生物过程中起着至关重要的作用。这些因子，被称为转录调节因子，基于它们在结构和功能上的相似性被归类为家族，并且已知哺乳动物发育所必需的螺旋-环-螺旋（HLH）家族的几个成员。HLH因子已被证明影响脑、眼和神经元发育、正常胰腺功能、巨噬细胞分化和骨骼肌发育。本项目为进一步研究HLH因子在发育调控中的确切作用奠定了基础。以秀丽隐杆线虫（Caenorhabditis elegans）为模型系统，本项目将包括：(1)通过对秀丽隐杆线虫基因组的数据库搜索，鉴定出秀丽隐杆线虫中所有的HLH因子；(2)在野生型动物和携带报告基因构建体的动物中，通过dsRNA干扰试验，确定一小部分预测的HLH因子的生物学功能。(3)通过原位杂交研究确定这些因子的表达模式。项目规划阶段的完成将提供所需的初步数据，以制定调节特定发育过程的HLH因素的详细、机制和分子特征。这项工作将最终导致细胞规范过程中组织特异性转录因子之间相互作用的生化和遗传分析。

JohnsonThe normal development of vertebrate organisms requires the careful orchestration of events at the molecular level. As a result, factors that regulate gene expression play critical roles in biological processes such as cellular specification, morphogenesis, and growth. These factors, known as transcriptional regulators, have been grouped together into families based on their similarities in structure and function, and several members of the helix-loop-helix (HLH) family are known to be required for mammalian development. HLH factors have been shown to affect brain, eye, and neuronal development, normal pancreatic functioning, macrophage differentiation, and skeletal muscle development. This project lays the foundation for further investigation into the exact role of HLH factors in developmental regulation. By using the nematode, Caenorhabditis elegans, as a model system, this project will involve (1) the identification of all of the HLH factors in C. elegans through database searches of the C. elegans genome, (2) the determination of the biological function of a small subset of predicted HLH factors through dsRNA interference assays in wild type animals and in animals carrying reporter constructs, and (3) the determination of the expression pattern of those factors through in situ hybridization studies. The completion of the planning stage of the project will provide preliminary data needed to develop a detailed, mechanistic and molecular characterization of HLH factors that regulate a specific developmental process. This work will ultimately lead to a biochemical and genetical analysis of the interactions between tissue-specific transcription factors during cellular specification.