Identification and characterization of regulators of neuronal differentiation during planarian regeneration

涡虫是一种淡水扁虫，它们具有非凡的才能，可以再生失去的身体部位，甚至是头部。这种现象是由于大量的新生细胞，成体干细胞可以在伤口分化成任何类型的涡虫细胞。尽管涡虫因此成为干细胞生物学的一个新兴模型，但对于哪些信号指定新母细胞的命运并触发它们的分化，我们知之甚少。最近可用的基因组测序与RNAi相结合，使我们现在能够大规模地研究涡虫基因功能。我们计划在涡虫中使用RNAi来识别再生神经系统的调节者和组织者。由于细胞间的通讯依赖于分泌因子，我们将生成一个针对涡虫基因组中所有分泌蛋白编码的RNAi文库。通过系统地敲除这些基因，并随后用神经元特异性抗体对再生神经系统进行分析，我们希望找到神经元分化和生长的新调节因子。新蛋白将在二级分析中分析其分子功能、表达模式、相互作用伙伴，以及它们在高等生物（如青蛙和果蝇）中的保存和功能。

Planarians are freshwater flatworms that have the remarkable talent to regrow lost body parts, even the head. This phenomenon is due to a high number of neoblasts, adult stem cells that can differentiate into any planarian cell type at the wound. Even though planarians are therefore an emerging model for stem cell biology, little is known about which signals specify neoblast fate and trigger their differentiation. The recent availability of a sequenced genome in combination with RNAi enables us now to study planarian gene function on a largescale basis. We plan to use RNAi in planarians to identify regulators and organizers of the regenerating nervous system. As cell-to-cell communication depends on secreted factors, we will generate an RNAi library against all secreted proteins encoded in the planarian genome. By systematic knockdown of these genes and subsequent analysis of the regenerating nervous system with neuron-specific antibodies, we hope to identify novel regulators of neuronal differentiation and growth. Novel proteins will be analyzed in secondary assays for their molecular functions, expression patterns, interaction partners, and their conservation and function in higher organisms such as frogs and Drosophila.