Role of BMP and FGF signaling during limb development

我们正在研究FGF和BMP信号之间的相互关系。肢体发育是这类研究的理想对象，因为它提供了丰富的信息，描述了肢体三轴的遗传途径和信号分子。目前的肢体发育模型表明，BMP信号在控制间充质趾间细胞中发生的正常细胞死亡中起作用，塑造最终的数字模式，但BMP在这一过程中的确切作用尚不清楚。通过同时失活BMP受体基因，Bmpr1a以及Fgf8和Fgf4，特别是在肢芽外胚层，我们已经产生了一种新的模型，其中表面外胚层必须接收BMP信号，从而导致FGF的下调，这反过来又诱导细胞凋亡的基础间充质的遗传证据。因此，BMP和FGF两者协同控制程序性细胞死亡的基本细胞功能。我们正在通过研究BMP和FGF信号在肢体发育的各个方面的作用来扩展这些研究，使用在发育肢体的特定区域表达Cre的小鼠品系。

We are studying the inter-relationship between FGF and BMP signaling. Limb development is ideal for such studies because of the wealth of information describing the genetic pathways and signaling molecules that pattern the three axis of the limb. Current models of limb development suggest that BMP signaling plays a role in controlling the normal cell death that occurs in mesenchymal interdigit cells, sculpting the final digit pattern, but the exact role of BMPs in this process are unknown. By simultaneously inactivating the Bmp receptor gene, Bmpr1a as well as Fgf8 and Fgf4 specifically in the limb bud ectoderm, we have produced genetic evidence for a novel model in which the surface ectoderm must receive a BMP signal, resulting in down regulation of FGFs which in turn induces apoptosis of the underlying mesenchyme. Thus both BMPs and FGF cooperate to control the essential cell function of programmed cell death. We are extending these studies by studying the role of BMP and FGF signaling in various aspects of limb development using mouse lines that express Cre in specific region of the developing limb.