lin 4 independent translational repression of lin 28

描述(由申请人提供) 线虫胚胎后发育时间受异时性调控 基因。LIN-28的临时下调对于执行 幼虫阶段3(L3)程序，一个独立于LIN-4的新途径，涉及 核激素受体daf-12对LIN-28起抑制作用。这样做的目的是 建议确定LIN-4非依赖的分子机制 对LIN-28的抑制(LIR)，并鉴定与此时序相关的基因 机制。首先，将检验DAF-12在翻译上的假设 抑制LIN-28，从而指定进入L3阶段。为了测试这一点，我 将分析LIN-28在幼虫发育过程中的mRNA和蛋白水平 野生型和daf-12突变型。其次，将检验这一假设 LIN-28的3‘非编码区中的元件对LIR依赖是足够的 LIN-28的下调和进入L3所需的。GFP记者 具有完整或截短的LIN-28 3‘非编码区序列的构建体将用于 测试充分性并确定特定的LIR元素。最后，基因筛查 将被用于确定LIR途径的新组件。这项建议 有令人兴奋的潜力来识别新的小的时间RNA调节器 发育时序，它正在成为一种常见的调节模式，从 从老鼠到男人。

DESCRIPTION (provided by applicant) In C. elegans post-embryonic developmental timing is regulated by heterochronic genes. The temporal downregulation of lin-28 is necessary for the execution of the larval stage 3 (L3) program, a novel pathway independent of lin-4 involving the nuclear hormone receptor daf-12 acts to repress lin-28. The aims of this proposal are to determine the molecular mechanism of lin-4-independent repression (LIR) of lin-28 and to identify genes essential for this timing mechanism. First, the hypothesis will be tested that daf-12 translationally represses lin-28 and thereby specifies entry into the L3 stage. To test this, I will analyze lin-28 mRNA and protein levels during larval development in wildtype and daf-12 mutant genotypes. Secondly, the hypothesis will be tested that elements in the 3' UTR of lin-28 are sufficient for LIR-dependent downregulation of lin-28 and are required for entry into L3. GFP reporter constructs with intact or truncated lin-28 3' UTR sequences will be used to test sufficiency and identify specific LIR elements. Lastly, a genetic screen will be performed to identify new components of the LIR pathway. This proposal has the exciting potential to identify new small temporal RNAs regulators of developmental timing, which is emerging as a common mode of regulation from mouse to man.