TRANSGENIC AND CHIMERIC-TRANSGENIC MOUSE MODELS FOR GASTRIC EPITHELIUM BIOLOGY

胃肠道上皮经历快速和永久的更新。 多能干细胞使子代细胞产生 多种终末分化的细胞类型。这一过程 增殖/分化在许多方面组织得非常好 空间维度。形成这一现象的分子机制 这种地理差异的建立和维持是 人们对此知之甚少。这项拨款计划的重点是转基因技术的使用。 小鼠绘制调控细胞特异性和区域的顺式作用元件- 胃上皮细胞中基因表达的特殊模式。这个 胃含氧腺体含有四种不同类型的外分泌。 细胞以及一些内分泌细胞。他们的血统也不是 人们对它们的关系及其分化途径也没有很好的了解。 内源性因子(IF)基因转录仅限于主因子和 含氧腺的壁细胞。我们将链接不同部分的 小鼠IF基因的5‘非转录结构域报告--人类的生长 激素基因-并定义导致HGH表达的模式 转基因小鼠的胃肠道。RNA印迹杂交 免疫细胞化学方法将用于这些分析。这 将允许我们在以下情况下在功能上映射鼠标中的顺式作用元素 调控基因是前肠特异的和细胞特异的表达。 这些研究应该提供对调节机制的洞察 分化的胃上皮细胞群体中的基因表达。

The gastrointestinal epithelium undergoes rapid and perpetual renewal. Multipotent stem cells give raise to daughter cells that produce a variety of terminally differentiated cell types. This process of proliferation/differentiation is remarkably well organized in a number of spatial dimensions. The molecular mechanisms that underlie the establishment and maintainence of this geographic differentiation are poorly understood. This grant proposal focuses on the use of transgenic mice to map cis-acting elements that regulate cell-specific and region- specific patterns of expression of genes in the gastric epithelium. The oxyntic glands of the stomach contain four distinct types of exocrine cells as well as a number of endocrine cells. Neither their lineage relationships nor their differentiation pathways are well understood. Intrinsic factor (IF) gene transcription is restricted to the chief and parietal cells of oxyntic glands. We will link various portions of the mouse IF gene's 5' nontranscribed domain to a reporter- the human growth hormone gene - and define the resulting patterns of HGH expression in the gastrointestinal tract of transgenic mice. RNA blot hybridization and immunocytochemical methods will be used for these analyses. This will allow us to functionally map cis-acting elements in the mouse IF gene that regulate is foregut-specific and cell-specific expression. These studies should provide insights about the mechanisms that modulate gene expression in differentiating gastric epithelial cell populations.