BMP SIGNALLING IN EYE AND KIDNEY DEVELOPMENT

描述(申请人提供)：转化生长因子-β超家族成员 分泌型生长因子在形态发生中的基础作用 在整个开发过程中。我们之前的研究表明，骨骼 哺乳动物眼的个体发育过程中需要形态发生蛋白7 还有肾脏。此续订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中的作用。我们 将测试异种BMP取代BMP7功能的能力。至 评价BMP7在输尿管中表达的相对贡献 上皮和间充质，我们将有条件地灭活这些细胞中的BMP7 使用CRE-LOX技术的特定细胞类型。去调查它们的起源和 间质和间质之间的潜在相互作用，我们将在 使用二进制的VIVO。我们计划找出候选基因 通过转录图谱维持未诱导的间充质。 骨形态发生蛋白和转化生长因子-β/激活素调控的Smads的表达结构域以及 抑制性SMADS将被描述。我们将利用一个条件等位基因 Smad1选择性地从后肾间充质中删除Smad1功能。至 阻断转化生长因子-β/骨形态发生蛋白信号，在间质中表达Cre的转基因小鼠 也会与携带条件性Smad4等位基因的动物杂交。信号 负责下调Smad的表达 将对间充质/上皮细胞转化进行分析。评估候选WNT的步骤 来自新诱导的间充质细胞或来自 输尿管芽、Smad的表达将在WNT4突变的肾脏组织中进行评估， 在稳定表达的成纤维细胞上生长的分离间充质细胞中 选择性Wnt蛋白。总的来说，这些实验应该会提供一些见解 转化生长因子-β信号通路在发育中的肾脏。

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.