Regeneration of Imaginal Discs in Drosophila

描述（由申请人提供）：拟议实验的重点是研究器官发生过程中细胞层之间的细胞信号传导机制。我们之前的工作表明，果蝇成虫盘中的柱状细胞和足周细胞都以精确的比例生长，这表明全局尺寸控制机制的协调调节。该提案的第一个具体目标是提供两个细胞层之间信号传导途径的分子描述。对果蝇成虫盘的研究是有利的，因为在识别出通路后，我们可以去除或激活该通路的成分。这将告诉我们该途径是否仅用于大小控制或器官识别或两者兼而有之。根据初步数据，我们的研究重点是两个细胞层之间的 wg、dpp、hh 和胰岛素信号传导通路。 在果蝇中，就像在其他生物体中一样，器官受伤后，伤口就会愈合。成虫盘的切口将两个细胞层结合在一起，并且两个细胞层不久之后融合。该提案的第二个目标是检查第一个具体目标中确定的分子信号是否也在伤口愈合后的再生中发挥作用。初步观察表明，wingless 会诱导再生所需的命运图谱变化。了解分子信号传导如何提高再生过程中的发育效力是干细胞生物学的关键。

DESCRIPTION (provided by applicant): The focus of the proposed experiments is to investigate cell signaling mechanisms between cell layers during organogenesis. Our previous work has shown that the columnar cells and the peripodial ceils in imaginal discs of Drosophila both grow in precise proportion to each other, suggesting coordinated regulation by a global size control mechanism. The first specific aim of this proposal is to provide a molecular description of the signaling pathways between the two cell layers. Studies with Drosophila imaginal discs are advantageous because upon identification of a pathway, we can remove or activate components of the pathway. This will tell us whether the pathway is only used for size control or organ identity or both. Based on preliminary data we focus our study on the wg, dpp, hh, and insulin signaling pathways between the two cell layers. In Drosophila, just as in other organisms, upon the wounding of an organ, wound healing occurs. A cut through an imaginal disc brings two cell layers together, and the two cell layers fuse shortly afterwards. The second aim of the proposal examines whether the molecular signals identified in the first specific aim also function in regeneration after wound healing. Preliminary observations indicate that wingless induces fate map changes necessary for regeneration. An understanding of how molecular signaling increases developmental potency during regeneration is key for stem cell biology.