MOLECULAR GENETICS OF PANCREAS DEVELOPMENT

这项工作的长期目标是了解胰腺的细胞和分子机制。 脊椎动物胚胎发生过程中的发育。在过去的两年半里，我们为 利用表达绿色荧光蛋白的转基因斑马鱼表达调控胰腺发育的基因 内胚层和内胚层来源的器官。我们还开发了全蒙免疫染色技术。 技术，并利用新的转基因品系来鉴定这些突变体。重要的是，我们进行了 对斑马鱼野生型胰腺发育的详细分析(菲尔德等人，2003b)，这项研究有 促进了斑马鱼系统的使用，以识别和/或测试与这一过程有关的基因。 具体地说，我们发现斑马鱼的胰腺是由两个芽融合而成的，一个是后部的 它只包含胰岛细胞，前面的细胞产生外分泌细胞和胰腺。 风管。胰管反过来又产生新的胰岛细胞。内分泌和内分泌的最初分离 外分泌血统应该有助于他们的研究。 我们建议继续我们的研究，具体目标如下。 1)分析从我们的筛选中鉴定和回收的胰腺突变。 2)进一步鉴定6个突变体，包括详细的表型分析和受影响的分离 吉恩。 3)分析周围组织在胰腺发育和β细胞分化中的作用。我们 将详细分析最初的胰岛细胞(形成后芽的细胞)的出现。 确定调控这一过程的信号的目标。这些信息将对设计单元格很有用 将干细胞分化为β细胞的培养方案。我们还将测试发出信号的假设 来自侧板的中胚层控制着胰腺前芽的发育，以及 从胰管中出现新的胰岛细胞。 4)继续开发试剂和技术，以促进将斑马鱼用作快速筛查 基因调控胰腺发育和β细胞分化的工具。

The long-term goals of this work are to understand cellular and molecular mechanisms of pancreas development during vertebrate embryogenesis. Over the past 2.5 years, we have conducted ascreen.for genes regulating pancreas development using a transgenic zebrafish line expressing GFP in the endoderm and endoderm-derived organs. We have also developed wholemount immunostaining techniques and utilized novel transgenic lines to characterize these mutants. Importantly, we carried out a detailed analysis of wild-type pancreas development in zebrafish (Field et al., 2003b), a study that has facilitated the use of the zebrafish system to identify and/or test genes implicated in this process. Specifically, we found that the zebrafish pancreas is formed by the fusion of two buds, a posterior one that contains only islet cells and an anterior one that gives rise to the exocrine cells and the pancreatic duct. The pancreatic duct in turn gives rise to new islet cells. This initial separation of endocrine and exocrine lineages should facilitate their investigation. We propose to continue our studies with the following specific aims. 1) Analyze the pancreas mutants identified and recovered from our screen. 2) Further characterize 6 mutants including detailed phenotypic analysis and isolation of the affected gene. 3) Analyze the role of the surrounding tissues in pancreas development and beta cell differentiation. We will analyze in detail the emergence of the initial islet cells (those that form the posterior bud) with the goals of identifying the signals that regulate this process. This information will be useful for designing cell culture protocols to differentiate stem cells into beta cells. We will also test the hypotheses that signals from the lateral plate mesoderm control the development of the anterior pancreatic bud, as well as the emergence of new islet cells from the pancreatic duct. 4) Continue to develop reagents and techniques to facilitate the use of the zebrafish as a rapid screening tool for genes regulating pancreas development and beta cell differentiation.