Analysis of zebrafish exocrine pancreas development

斑马鱼外分泌胰腺发育分析

• 批准号: 6417988
• 负责人: Nelson Shu-Sang Yee
• 金额: $ 13.02万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6417988
• 关键词: acinar cell; developmental genetics; gene mutation; genetic mapping; histogenesis; molecular cloning; nonmammalian vertebrate embryology; pancreas; zebrafish

DESCRIPTION (provided by applicant) During vertebrate development, precise regulation of cellular proliferation and differentiation is essential for normal organ morphogenesis. Alterations in these processes can lead to neoplastic transformation of a wide range of cell types including the ductular cells and exocrine glands of the pancreas. The coexistence of exocrine and endocrine cells within the pancreas makes it a unique model organ for studying epithelial differentiation and cell fate specification. The pancreatic enzymes and hormones can be readily assayed as markers for exocrine and endocrine differentiation, and molecular markers that characterize different stages of cell fate specification have recently been identified. However, the molecular mechanism that regulates histogenesis and cytodifferentiation of the exocrine pancreas is poorly understood. Continued effort in this area of basic research is important because it is essential to the understanding of normal pancreas development and the early steps of exocrine neoplastic transformation. To identify genes that regulate pancreatic differentiation, a chemical-induced mutagenesis screen in the zebrafish has been performed using exocrine and islet markers. One identified mutant, no exocrine pancreas (nep), lacks immunoreactivity for the pancreatic exocrine enzyme carboxypeptidase A although the exocrine precursor cells are present. As a result, we hypothesize that the nep gene product plays a crucial role in regulating differentiation of the exocrine pancreas and is therefore important for understanding the molecular pathway regulating exocrine pancreas development and possibly pancreas tumorigenesis. In this award application, we propose a strategy to analyze the phenotype of the nep mutant and to identify the actual nep gene. By examining the morphological defect of the nep mutant using histological, ultrastructural and immunohistological techniques, the stage at which exocrine pancreas development is perturbed by the nep mutation can be determined. Testing whether the nep gene acts in a cell-autonomous manner to direct exocrine differentiation will help define the nature of the nep gene function. The chromosomal location of the nep gene will be mapped meiotically using bulked segregant analysis. The region surrounding the nep locus will be delimited by fine resolution meiotic and physical mapping techniques. This analysis will allow us to define the genomic region immediately surrounding the nep locus and ultimately to clone the nep gene. Given the similar development and physiology of the teleost and mammalian pancreas, the genes that direct pancreatic organogenesis are likely to be closely related. Characterization of the nature of the nep gene function and identification of the nep gene will help shed light on the mechanism underlying differentiation of exocrine precursor cells. These data will likely advance our understanding of epithelial differentiation and the development of pancreatic cancer.

描述（由申请人提供） 在脊椎动物发育期间，精确调节细胞增殖和 分化对于正常器官形态发生至关重要。改变 这些过程可能导致各种细胞的肿瘤转化 包括胰腺的导管细胞和外分泌腺的类型。这 胰腺内外分泌和内分泌细胞的共存使其成为 用于研究上皮分化和细胞命运的独特模型器官 规格。胰腺酶和激素可以很容易地被分析为 外分泌和内分泌分化的标记，以及分子标记 最近已经表征了不同阶段的细胞命运规范 确定。但是，调节组织发生和 外分泌胰腺的细胞分化知之甚少。持续 在这一基础研究领域的努力很重要，因为这对于 对正常胰腺发展的理解和 外分泌肿瘤转化。 为了鉴定调节胰腺分化的基因，化学诱导的 斑马鱼中的诱变屏幕已使用外分泌和胰岛进行 标记。一个发现突变体，没有外分泌胰腺（NEP），缺乏 胰腺外分泌酶羧肽酶的免疫反应性虽然 存在外分泌前体细胞。结果，我们假设 NEP基因产物在调节分化方面起着至关重要的作用 外分泌胰腺，因此对于理解分子很重要 调节外分泌胰腺发育和胰腺的途径 肿瘤发生。在此奖项申请中，我们提出了一项策略来分析 NEP突变体的表型并确定实际NEP基因。通过检查 使用组织学超微结构的NEP突变体的形态缺陷 和免疫组织学技术，这是外分泌胰腺的阶段 可以确定NEP突变的发育受到干扰。测试是否 NEP基因以细胞自主的方式起作用来指导外分泌 分化将有助于定义NEP基因功能的性质。这 NEP基因的染色体位置将使用大量映射 分类分析。 NEP基因座周围的区域将由 精细的分辨率减数分裂和物理映射技术。该分析将会 允许我们定义立即围绕NEP基因座的基因组区域和 最终要克隆NEP基因。 鉴于Teleost和哺乳动物的类似发展和生理 胰腺，直接胰腺器官发生的基因可能是 密切相关。 NEP基因功能和 NEP基因的识别将有助于阐明基础机制 外分泌前体细胞的分化。这些数据可能会推动我们的 了解上皮分化和胰腺的发展 癌症。