THYROID HORMONE CONTROL OF A GENE EXPRESSION NETWORK

基因表达网络的甲状腺激素控制

• 批准号: 6517574
• 负责人: JOHN DAVID FURLOW
• 金额: $ 15.3万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-15 至 2004-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6517574
• 关键词: DNA footprinting; Xenopus; apoptosis; binding sites; collagenase; cysteine endopeptidases; developmental genetics; gel mobility shift assay; gene expression; gene induction /repression; genetic enhancer element; genetic regulatory element; genetically modified animals; hormone receptor; hormone regulation /control mechanism; metamorphosis; molecular cloning; nucleic acid sequence; reporter genes; thyroid hormones; transcription factor

Amphibian metamorphosis presents an excellent opportunity to study how hormones control gene expression networks in a tissue-specific and development stage-specific manner. During the transition from the larval tadpole to the adult frog, thyroid hormone controls the growth and differentiation of new adult structures, the remodeling of existing structures for a an adult frog, thyroid hormone lysis of entire larval organs. These morphogenetic changes are caused by gene expression changes mediated by the nuclear thyroid hormone receptors. Subtractive hybridization and candidate gene approaches have identified between twenty and thirty thyroid hormone induced and repressed genes in the reabsorbing tadpole tail, an example of hormonally controlled programmed cell death examined the downstream am signaling events that culminate in tissue specific biological responses. Furthermore, current methods such native chrromatin. We propose to determine the mechanism of thyroid hormone activation of genes that are among the last to be induced in this gene expression cascade. The genes we have chosen to study encode a secreted matrix metalloproteinase, collagenase-3 , and an intra cellular cell death inducing protease, caspase-3. Collagenase- 3 is the most strongly up-regulated gene in dying muscle cells. We will use two complementary approaches to identify and characterize the Th- responsive and basal regulatory elements in these two sequenced. The ideal test of a candidate regulatory sequence is whether or not it can support appropriate transcriptional regulation in vivo. Thus, we will recently developed transenic technologies in Xenopus laevis to screen for the minimal genomic fragment genomic DNA from the collagenase-3 and caspase-3 genes will be screened for sequences that bind to early induced transcription bind to important regulatory sequences will be functionally characterized in vivo using transgenic tadpoles, employing both gain- and hormone-induced gene expression cascade from the time of thyroid hor more binding to its receptors to the induction of a concepts, and molecular markers identified during the proposed work can be applied to other important yet complex biological problems. These include thyroid hormone control of the growth and differentiation of the amphibian limbs, and certainly steroid and thyroid hormone control of gene networks in adult and developing mammals.

两栖动物的变态为研究激素如何以组织特异性和发育阶段特异性的方式控制基因表达网络提供了绝佳的机会。 在从幼虫蝌蚪到成年青蛙的过渡过程中，甲状腺激素控制新成体结构的生长和分化、成年青蛙现有结构的重塑、整个幼虫器官的甲状腺激素裂解。 这些形态发生的变化是由核甲状腺激素受体介导的基因表达变化引起的。 消减杂交和候选基因方法已在重吸收蝌蚪尾部中鉴定出二十至三十个甲状腺激素诱导和抑制基因，这是激素控制的程序性细胞死亡的一个例子，检查了最终导致组织特异性生物反应的下游am信号事件。此外，目前的方法例如天然染色质。 我们建议确定甲状腺激素激活基因的机制，这些基因是该基因表达级联中最后被诱导的基因。 我们选择研究的基因编码分泌型基质金属蛋白酶、胶原酶-3 和诱导细胞内细胞死亡的蛋白酶、半胱天冬酶-3。 Collagenase-3 是垂死肌肉细胞中上调最强烈的基因。 我们将使用两种互补的方法来识别和表征这两个测序中的 Th 反应元件和基础调节元件。候选调控序列的理想测试是它是否能够支持体内适当的转录调控。 因此，我们最近将在非洲爪蟾中开发转基因技术，以筛选来自胶原酶-3和半胱天冬酶-3基因的最小基因组片段基因组DNA。 甲状腺激素与其受体的结合诱导了一个概念，并且在拟议工作期间确定的分子标记可以应用于其他重要但复杂的生物学问题。 其中包括甲状腺激素对两栖动物四肢生长和分化的控制，当然还有类固醇和甲状腺激素对成年和发育中哺乳动物基因网络的控制。