REGULATION OF ADULT STEM CELLS IN ZEBRAFISH

描述（由申请人提供）：脊椎动物，如斑马鱼，使用成体干细胞（ASCs）从胚胎中培养成体，并用于其组成组织的稳态和修复。ASCs的缺陷是多种疾病和综合征的原因，包括再生障碍性贫血和头发变白。我们开发了斑马鱼黑素细胞干细胞（MSC）作为研究ASC调控的模型。在本研究中，我们开发了克隆标记技术来研究神经嵴形成过程中间充质干细胞如何从直接发育谱系中分离出来，以及不同的分子机制如何控制间充质干细胞调控的不同方面。一些ASCs以及癌症干细胞的一个关键特征是增殖和静止状态之间的转换。在斑马鱼幼虫中，黑素细胞的发育大部分在受精后3天完成。分化的黑素细胞抑制或施加静止作用，阻止3dpf后黑素细胞的发育。我们已经确定了导致斑马鱼幼虫体内黑色素细胞过量发育的药物。我们将验证这一假设，即这些药物起到缓解抑制的作用，使间充质干细胞从静止到增殖。我们还将探讨抑制缓解药物是否会使静止的MSC对细胞周期依赖性化疗药物（如奥沙利铂）敏感。我们将使用我们的实验来区分晚期发育过量的黑素细胞和早期黑素细胞，对MSC中调节抑制和静止的基因突变进行无偏筛选。

DESCRIPTION (provided by applicant): Vertebrate animals, such as zebrafish, use Adult Stem Cells (ASCs) to grow the adult from the embryo and for homeostasis and repair of its constitutive tissues. Defects in ASCs are responsible for a variety of diseases and syndromes, including aplastic anemias and hair graying. We have developed the zebrafish melanocyte stem cell (MSC) as a model for studying ASC regulation. In this proposal, we develop clonal labeling techniques to investigate how the MSC segregates from Direct-Developing lineages in the forming neural crest, and how different molecular mechanisms control different aspects of MSC regulation. A key feature of some ASCs, as well as cancer stem cells, is the transitions between proliferative and quiescent states. In the zebrafish larvae, melanocyte development is largely completed by 3 days post fertilization (dpf). Differentiated melanocytes repress, or impose quiescence, on MSC, preventing melanocyte development after 3dpf. We have identified drugs that cause development of excess melanocytes in the larval zebrafish. We will test the hypothesis that these drugs act to relieve repression, transiting the MSC from quiescence to proliferation. We will also ask whether repression-relieving drugs sensitize the quiescent MSC to cell cycle-dependent chemotherapeutics such as oxaliplatin. We will use our assay to distinguish between late developing excess melanocytes from early melanocytes to perform an unbiased screen for mutations in genes that regulate repression and quiescence in the MSC.