BMP SIGNALLING IN EYE AND KIDNEY DEVELOPMENT

描述（由申请人提供）：TGF-β超家族成员 分泌的生长因子在形态发生中起着重要作用 整个发展过程。我们之前的研究表明， 形态发生蛋白7（MorphogeneticProtein 7，BMP 7）在哺乳动物眼的个体发育过程中是必需的 和肾脏。本更新申请中概述的实验旨在阐明我们的 了解BMP在肾脏发育和形态发生过程中的功能。我们 将测试异源BMP替代BMP 7功能的能力。到 评估输尿管中BMP 7表达的相对贡献 上皮和间充质，我们将有条件地将BMP 7在这些 使用Cre-lox技术的特定细胞类型。为了调查起源， 基质和间充质之间潜在的相互作用，我们将标记细胞 体内使用二元系统。我们计划找出负责 通过转录谱分析维持未诱导的间充质。 BMP和TGF-β/激活素调节Smads的表达结构域，以及 将描述抑制性Smads。我们将利用一个条件等位基因 Smad 1选择性地从后肾间充质中删除Smad 1功能。到 破坏TGF-β/BMP信号，在间质中表达Cre的转基因小鼠 也将与携带条件性Smad 4等位基因的动物杂交。信号 负责下调Smad的表达， 将分析间充质/上皮转化。评估候选Wnt 信号来源于新诱导的间充质或来自 输尿管芽，将在Wnt 4突变肾组织中评估Smad表达， 在稳定转染的成纤维细胞上生长的分离的间充质中， 选择性Wnt蛋白。总的来说，这些实验 转化生长因子-β信号通路。

DESCRIPTION (provided by applicant): Members of the TGF-beta superfamily of secreted growth factors play fundamental roles governing morphogenetic processes throughout development. Our previous studies have shown that Bone Morphogenetic Protein7 (BMP7) is required during ontogeny of the mammalian eye and kidney. Experiments outlined in this renewal application aim to clarify our understanding of BMP functions during kidney development and morphogenesis. We will test the ability of heterologous BMPs to replace BMP7 functions. To evaluate the relative contribution of BMP7 expression in the ureteric epithelium and mesenchyme, we will conditionally inactivate BMP7 in these specific cell types using Cre-lox technology. To investigate the origins and potential interactions between stroma and mesenchyme, we will mark cells in vivo using a binary system. We plan to identify candidate genes responsible for maintenance of the uninduced mesenchyme by transcriptional profiling. Expression domains of BMP and TGF-beta /activin regulated Smads, as well as the inhibitory Smads will be described. We will exploit a conditional allele of Smad1 to selectively delete Smad1 function from the metanephric mesenchyme. To disrupt TGF-beta /BMP signals, transgenic mice expressing Cre in the mesenchyme will also be crossed to animals harboring a conditional Smad4 allele. Signals responsible for down regulation of Smad expression during the mesenchymal/epithelial transition will be analyzed. To evaluate candidate Wnt signals originating from either the newly induced mesenchyme or from the ureteric bud, Smad expression will be assessed in Wnt4 mutant kidney tissue, and in isolated mesenchymes grown on stably transfected fibroblasts expressing selective Wnt proteins. Collectively these experiments should provide insight into TGF-beta signaling pathways in the developing kidney.