Gene expression in the mammalian intestine

人类胃肠道常见疾病，包括先天性畸形、炎症性疾病 肠道、乳糜泻和消化性溃疡疾病、肠道特有感染和癌症导致相当高的发病率。 以及美国的死亡率。尽管其中许多疾病的病理生理学可能与 研究正常肠道发育机制、细胞分化和分子调控的基本途径 对哺乳动物肠道的胚胎发育知之甚少。对于分子基础来说尤其如此 肠道的关键调节因子--肠上皮与其下层间充质的相互作用 发展和动态平衡。这项提议寻求利用最近的技术进步来发起一项 哺乳动物肠道发育和器官发生的系统分子分析；目标和 实验方法与RFA#DK-01-023的大纲密切一致。我们将从检查开始 13-15岁关键时期基因转录谱的数量和质量变化 在小鼠怀孕的日子里，当肠道内胚层经历一个重要的细胞转变，从一个糟糕的 分化的假复层组织形成原始的绒毛上皮。两个独立序列的初步分析 对这些发育阶段制备的基因表达(SAGE)文库的分析从统计学上揭示了 令人惊讶的少数基因表达水平的显著变化，包括几个假定的 细胞间通讯、基因转录和细胞内信号的调节。其中一些变化 被认为是推动获得细胞命运和形态以及组织形态和功能的 发展中的小肠。该项目的具体目标包括对这些圣人进行更详细的描述 图书馆，这是该领域的独特资源，特别着眼于确定早期的一些关键监管机构 肠上皮的分化和间充质-上皮的相互作用。我们进一步建议研究 预测在细胞间相互作用中发挥作用的基因的mRNA表达部位，从而开始定位关键 肠道发育中的候选信号通路是开发实用的基因检测策略的前奏 更直接地发挥作用。最后，我们将在空间和时间上扩展这种分析，通过研究动态 在小肠发育的另外两个阶段和在小肠发育的平行阶段基因表达的变化 胃和结肠的发育。由此产生的对哺乳动物肠道发育的全面分析， 很可能是第一个，将阐明正常发育过程的一些基本方面，以及 应有助于改善对胃肠道常见疾病的理解和治疗。

Common disorders of the human gastrointestinal (Gl) tract, including congenital malformations, inflammatory bowel, celiac and peptic ulcer disease, intestine-specific infections and cancer, result in considerable morbidity and mortality in the United States. Although the pathophysiology of many of these disorders is likely related in fundamental ways to mechanisms of normal gut development, the molecular regulation of cell differentiation and fetal development of the mammalian intestine is poorly understood. This is particularly true for the molecular basis of the interaction between gut epithelium and its underlying mesenchyme, a key regulator of intestinal development and homeostasis. This proposal seeks to exploit recent technological advances to initiate a systematic molecular analysis of mammalian intestinal development and organogenesis; the goals and experimental methods are closely aligned with the outline of RFA #DK-01-023. We will begin by examining quantitative and qualitative changes in the gene transcription profile during the critical interval between 13 and 15 days in mouse gestation, when the gut endoderm undergoes an important cellular transition from a poorly differentiated, pseudostratified tissue into a primitive villous epithelium. Preliminary analysis of two separate Serial Analysis of Gene Expression (SAGE) libraries prepared from these developmental stages reveals statistically significant changes in the expression levels of a surprisingly small number of genes, including several putative regulators of intercellular communication, gene transcription, and intracellular signaling. Some of these changes are presumed to drive the acquisition of cellular fate and morphology and tissue form and function in the developing small bowel. The Specific Aims of the project involve more detailed characterization of these SAGE libraries, a unique resource in the field, with a special view toward identifying some of the critical regulators of early intestinal epithelial differentiation and mesenchymal-epithelial interactions. We further propose to examine the sites of mRNA expression for genes predicted to function in intercellular interactions and hence begin to map key candidate signaling pathways in gut development as a prelude to developing practical strategies to examine gene function more directly. Finally, we will expand this analysis in space and in time, by investigating the dynamic alterations in gene expression at two additional stages in small bowel development, and at parallel stages in development of the stomach and colon. The resulting comprehensive analysis of mammalian gut development, quite possibly the first of its kind, will elucidate some essential aspects of normal developmental processes and should contribute to improved understanding and treatment of common disorders of the Gl tract.