Exocrine Pancreas & Intestinal Epithelial Development

描述（申请人提供）： 外分泌胰腺和肠在脊椎动物中起着重要的作用 physiology.对于这两种器官，细胞更新也具有重要的稳态作用。 作用在肠中，绒毛上皮细胞连续地 被干细胞祖细胞的分化后代所取代， 在每个绒毛周围的隐窝中。在胰腺中，多能的 祖细胞存在于小管上皮内，并被认为是 分化的内分泌细胞和腺泡细胞的来源，可以替代丢失的细胞 在特定的实验和病理条件下。识别 调节消化道细胞谱系特化和分化的基因 器官干细胞祖细胞对于人类相关研究具有重要意义。 胰腺癌和结肠癌等疾病。基因分析是一种 鉴定调控发育过程的基因的有效手段， 尤其是器官发生。在本申请中，我们概述了 谱系特化和细胞分化的分子特征 脊椎动物斑马鱼的外分泌胰腺和肠 模型系统非常适合这个目的。外分泌胰腺和 斑马鱼幼虫的肠道在受精后5天开始发挥作用，‑ 阶段适合于标准诱变技术。此外，祖细胞和 两个器官的分化细胞在整个过程中都很容易观察到。 使用器官特异性标记的发育。本申请的第一个目的是 进行系统的突变筛选， 胰腺和肠外分泌期细胞分化 发展使用原位和组织化学分析，我们将确定基因 调节胰腺外分泌的生长和分化， 肠的杯状和肠内分泌细胞谱系的发育。 最近的一项试点研究证明了这种筛选的可行性。的 第二个目的是鉴定胰腺外分泌的分子标记物， 通过产生斑马鱼胰腺和肠来获得幼斑马鱼的肠 EST数据库。这一目标将与联合国环境规划署 斑马鱼基因组群落第三个目标是定位突变和EST 利用减数分裂和物理作图技术。这一目标将使 鉴定特异性目的中回收突变的候选基因 1，并为基因敲除实验提供靶标数据库。第四 本申请的目的是探索新基因的功能， 具体目标2使用基于吗啉代的基因敲除策略。

DESCRIPTION (Provided by Applicant): The exocrine pancreas and intestine play essential roles in vertebrate physiology. For both organs cell renewal also has an important homeostatic role. In the intestine, cells of the villus epithelium are continuously replaced by the differentiated progeny of stem cell progenitors that reside within the crypts surrounding each villus. In the pancreas, multipotent progenitors reside within the ductular epithelium and believed to serve as a source of differentiated endocrine and acinar cells that can replace cells lost under specific experimental and pathological conditions. Identification of the genes that regulate cell lineage specification and differentiation of digestive organ stem cell progenitors is important to research related to common human diseases such as cancers of the pancreas and colon. Genetic analysis is an efficient means to identify genes that regulate developmental processes, particularly organogenesis. In this application we outline a strategy for the molecular characterization of lineage specification and cell differentiation in the developing exocrine pancreas and intestine of the zebrafish, a vertebrate model system uniquely suited to this purpose. The exocrine pancreas and intestine of zebrafish larvae function at five days post‑fertilization, a stage amenable to standard mutagenesis techniques. Further, progenitors and differentiated cells of both organs are easily visualized throughout development using organ specific markers. The first Aim of this application is to perform a systematic mutagenesis screen for genes that regulate lineage specification and cell differentiation during exocrine pancreas and intestinal development. Using in situ and histochemical analysis we will identify genes that regulate growth and differentiation of the exocrine pancreas as well as development of the goblet and enteroendocrine cell lineages of the intestine. The feasibility of such as screen was proven in a recent pilot study. The second Aim is to identify molecular markers in the exocrine pancreas and intestine of larval zebrafjsh by generating a zebrafish pancreas and intestine EST database. This aim will be performed in collaboration with members of the zebrafish genome community. The third Aim is to map the mutations and ESTs using meiotic and physical mapping techniques. This aim will allow identification of candidate genes for the mutations recovered in Specific Aim 1, and provide a databank of targets for gene knockdown experiments. The fourth aim of this application is to explore the function of novel genes identified in Specific Aim 2 using a morpholino based gene knockdown strategy.