Zebrafish studies of exocrine pancreatic precursors

斑马鱼外分泌胰腺前体的研究

• 批准号: 6885382
• 负责人: Steven D Leach
• 金额: $ 16.35万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-15 至 2006-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6885382
• 关键词: acinar cell; antisense nucleic acid; bioinformatics; developmental genetics; embryogenesis; gastrointestinal epithelium; gene expression; gene expression profiling; genetically modified animals; in situ hybridization; morpholine; nonmammalian vertebrate embryology; nucleic acid sequence; pancreas; stem cells; subtraction hybridization; transcription factor; zebrafish

DESCRIPTION (provided by applicant): The identity and location of epithelial precursor cells in exocrine pancreas remain unknown. Further characterization of this precursor population would represent a significant advance in our understanding of pancreatic development, pancreatic regeneration and pancreatic cancer. While studies in mice and other rodents have provided important initial insights, these species have significant limitations related to many aspects of genetic manipulation. The zebrafish (Danio rerio) has recently emerged as a central model organism in the study of vertebrate development. The increasingly widespread use of the zebrafish reflects significant advantages with respect to embryo access, simplified techniques for gain-of-function and loss-of-function analysis, and forward genetic capabilities. Recent studies have suggested that many aspects of pancreas development in the zebrafish are conserved with respect to other vertebrate species. Based on a recent NIDDK program announcement requesting proposals for innovative and exploratory research involving pancreatic stem cells and/or novel animal models (PA-01-129), we have embarked on initial studies of zebrafish exocrine pancreas development. The long-term goal of this research program is to identify and rigorously characterize exocrine pancreatic precursors in zebrafish pancreas, ultimately allowing use of this organism as a novel model system for study of human pancreatic disease. Our preliminary studies have involved cloning and characterization of the zebrafish orthologue for PTF1a-p48, a basic helix-loop-helix transcription factor required for normal pancreas development in the mouse. Initial gene expression and p48 morpholino knock-down studies have suggested fundamental and informative differences between zebrafish and mouse with respect to the relationship between endocrine and exocrine precursor pools. Based on these findings, we propose that identification and characterization of p48-positive precursors in zebrafish pancreas will allow investigation of conserved regulatory mechanisms not discernable in the mouse, and that novel regulators of pancreatic development will be identified among genes differentially expressed in wild-type vs. p48 morphant embryos. To test these hypotheses, the following Specific Aims will be pursued: First, to rigorously determine the identity, location, and gene expression profiles of p48-positive precursor cells in developing zebrafish pancreas. Second, to determine the contribution of p48-positive precursors to endocrine and exocrine lineages; and finally, to identify novel p48 target genes responsible for mediating the effects of p48 on early pancreas development. It is anticipated that these studies will provide important new insights regarding regulation of exocrine pancreatic precursor cells, and further establish the zebrafish as a novel model system for the study of epithelial differentiation in exocrine pancreas.

描述（由申请人提供）：外分泌胰腺中上皮前体细胞的身份和位置仍然未知。对这种前体人群的进一步表征将是我们对胰腺发育，胰腺再生和胰腺癌的理解的重大进步。尽管在小鼠和其他啮齿动物的研究中提供了重要的初始见解，但这些物种具有与遗传操纵许多方面有关的重大局限性。斑马鱼（Danio Rerio）最近在脊椎动物发育研究中成为一种中央模型生物。斑马鱼的越来越广泛使用反映了在胚胎接入，简化功能获得和功能丧失分析以及正向遗传能力方面的显着优势。最近的研究表明，斑马鱼中胰腺发育的许多方面都是相对于其他脊椎动物的保守的。基于最近的NIDDK计划公告，要求提出有关涉及胰腺干细胞和/或新型动物模型的创新和探索性研究的建议（PA-01-129），我们已经开始对斑马鱼外分泌胰腺发育的初步研究。该研究计划的长期目标是确定并严格地表征斑马鱼胰腺中的外分泌胰腺前体，最终允许使用该生物作为研究人胰腺疾病的新型模型系统。我们的初步研究涉及对PTF1A-P48的斑马鱼直系同源物的克隆和表征，PTF1A-P48是小鼠正常胰腺发育所需的基本螺旋 - 环螺旋转录因子。最初的基因表达和p48形态敲低的研究表明，斑马鱼和小鼠之间在内分泌和外分泌前体池之间的关系方面存在基本和信息性差异。基于这些发现，我们提出，斑马鱼胰腺中P48阳性前体的鉴定和表征将允许研究小鼠中无法识别的保守调节机制，并且在野生型Pe中在基因中鉴定出胰腺发育的新型调节剂，并且会在野外表达中鉴定出来。 vs. P48形态胚胎。为了检验这些假设，将追求以下特定目标：首先，严格确定斑马鱼胰腺中P48阳性前体细胞的身份，位置和基因表达谱。其次，确定p48阳性前体对内分泌和外分泌谱系的贡献；最后，确定新型的P48靶基因，负责介导p48对胰腺早期发育的影响。可以预料，这些研究将提供有关调节外分泌胰腺前体细胞的重要新见解，并进一步建立斑马鱼，作为研究外分泌胰腺上皮分化的新型模型系统。