From Susceptibility to Signals: How Extrinsic Cues Alter Stem and Progenitor Cell

在眼睛发育过程中，祖细胞的增殖和分化必须小心 精心设计以确保产生合适大小和细胞组成的眼睛。 视网膜癌和神经退行性疾病被认为与 增殖分化。这个项目调查了外在线索和内在因素 在从增殖到分化的过渡过程中进行合作，探索 控制斑马鱼的眼睛生长和发育。斑马鱼特别容易受高- 分辨率成像和胚胎操作，允许发育事件 实时研究并与遗传、分子和细胞变化相关。 具体目标 目的1：研究细胞周期时相和细胞周期机制的组成 使细胞对局部分化信号敏感。 本节询问G2/M期的视网膜祖细胞(RPC)是否更容易感染 外在的分化线索。通过移植过度增殖或循环缓慢的突变细胞 在野生型宿主中，我们将评估循环的RPC对环境的敏感性 分化因素。 目的2：研究维甲酸信号如何改变视网膜干细胞的增殖。 这一目标是基于对一种新的小眼睛突变体的初步分析，在该突变体中，维甲酸 (RA)靶基因在外周视网膜的干细胞利基中上调。vbl.使用 药理学和遗传学方法，它检查了RA对增殖的影响， 分化和细胞周期动力学。 目的3：探讨背腹模式与干细胞介导的关系 斑马鱼视网膜的生长。 在这一目标中的实验使用了增益和损耗函数的方法以及 用于(1)评估Gdf6a介导的视网膜图案化是否 维持睫状体边缘带(CMZ)所必需的，CMZ是视网膜干细胞的生态位；和(2) 调查RA是否直接控制CMZ内的基因表达以直接调节 视网膜干细胞和祖细胞的行为。 意义：通过识别诱使视网膜祖细胞从增殖到 差异化，这个项目将影响我们对生长、修复和再生的理解 视网膜和整个中枢神经系统。

During eye development, progenitor cell proliferation and differentiation must be carefully orchestrated to ensure that an eye of the right size and cellular composition is generated. Retinal cancers and neurodegenerative diseases have been linked to an imbalance between proliferation and differentiation. This project investigates how extrinsic cues and intrinsic factors collaborate during the transition from proliferation to differentiation, probing the mechanisms that control eye growth and development in zebrafish. Zebrafish are particularly amenable to high- resolution imaging and embryological manipulations, allowing developmental events to be studied in real time and correlated with genetic, molecular, and cellular changes. SPECIFIC AIMS Aim 1: To investigate how cell cycle phase and components of the cell cycle machinery sensitize cells to local differentiation cues. This section asks whether retinal progenitor cells (RPCs) in G2/M are more susceptible to extrinsic differentiation cues. By transplanting mutant cells that hyperproliferate or cycle slowly into wild-type hosts, we will assess the susceptibility of cycling RPCs to environmental differentiation factors. Aim 2: To examine how retinoic acid signaling alters proliferation in a retinal stem cell niche. This aim is based on preliminary analysis of a novel small-eyed mutant in which retinoic acid (RA) target genes are upregulated throughout a stem cell niche in the peripheral retina. Using pharmacological and genetic approaches, it examines the impact of RA on proliferation, differentiation, and cell cycle kinetics. Aim 3: To probe the relationship between dorsal-ventral patterning and stem cell mediated growth in the zebrafish retina. The experiments in this aim employ gain- and loss-of-function approaches along with pharmacological manipulations to (1) assess whether Gdf6a-mediated patterning of the retina is required for maintenance of the ciliary marginal zone (CMZ), a retinal stem cell niche; and (2) investigate whether RA directly controls gene expression within the CMZ to directly modulate retinal stem and progenitor cell behaviors. Significance: By identifying mechanisms that coax retinal progenitor cells from proliferation to differentiation, this project will impact our understanding of growth, repair, and regeneration in the retina and the entire central nervous system.