Characterizing LIN-12/Notch Regulation and Activity

秀丽隐杆线虫的生命周期包含一种发育停滞状态，称为dauer， 应对不利的环境条件。这个dauer阶段是一个延长的细胞静止期 不仅与外阴前体细胞（VPC）的维持有关， 变成一种多能状态通常在开发过程中，VPC命运规范需要LIN-12/Notch，这是一个很好的 保守的跨膜受体和转录激活因子，用于靶基因的转录激活 来定义未来的小区标识。然而，在dauer过程中，这种转录激活被阻断，即使在 存在稳定且活化的LIN-12/Notch。此外，已经经历细胞命运的VPC LIN-12/Notch规范在dauer进入时被去分化为多能状态。该块 由胰岛素/胰岛素生长因子信号转导介导，由于其效应子的丧失，转录因子β- 16/FoxO，导致块的部分释放。研究分布式VPC如何能够防止LIN-12/Notch 信号，我将研究如何LAG-1，LIN-12/Notch激活复合物的DNA结合组分， 我将测试表达稳定的和功能性的LAG-1是否会减轻dauer VPC中的dauer表达。 块我还将进行阻断和未阻断之间的差异基因表达分析实验 dauer VPC，以寻找可能被证明对在静态和动态环境中维护VPC至关重要的候选VPC。 多能状态

The life cycle of Caenorhabditis elegans contains a developmentally arrested state called dauer that occurs in response to adverse environmental conditions. This dauer stage is a period of prolonged cellular quiescence that is associated with not only the maintenance but also reprogramming of the Vulval Precursor Cells (VPCs) into a multipotent state. Normally in development, VPC fate specification requires LIN-12/Notch, a well- conserved transmembrane receptor and transcriptional activator, for transcriptional activation of target genes to define the future cell identity. However, during dauer, this transcriptional activation is blocked, even in the presence of a stable and activated LIN-12/Notch. Moreover, VPCs that had already undergone cell fate specification by LIN-12/Notch are de-differentiated into a multipotent state upon dauer entry. This block is mediated by Insulin/Insulin Growth Factor Signaling, as loss of its effector, the transcriptional factor DAF- 16/FoxO, results in a partial relief of the block. To study how dauer VPCs are able to prevent LIN-12/Notch signaling, I will investigate how LAG-1, the DNA-binding component of the LIN-12/Notch activation complex, is regulated in dauer VPCs, and I will test whether expressing stable and functional LAG-1 will relieve the dauer block. I will also perform a differential gene expression analysis experiment between blocked and unblocked dauer VPCs to look for candidates that may prove essential for maintaining VPCs in a quiescent and multipotent state.