Immortal worms and stem cells: how do planarians replace and rescale during regeneration?

长出新的头、胳膊或腿显然是人类做不到的。但我们确实有一些细胞在需要时有一定的能力产生其他类型的细胞，例如在应对割伤或瘀伤时，我们能够治愈和替换受损的细胞。在这项研究中，将使用Planarian蠕虫来了解干细胞，再生和愈合的基本生物学。Planarians有大量的干细胞，能够产生其他细胞类型。例如，如果将一只涡虫切成小块，这些细胞将使每一片虫体再生成一个全新的，尽管更小的虫体。这项研究的目的是了解真涡虫的干细胞如何能够分裂并在新蠕虫的正确位置产生正确的细胞。如果我们能够理解这个过程，我们可能更接近于理解我们自己再生丢失或受损细胞的能力。这种类型的研究对于理解细胞丢失或损坏并需要新细胞的疾病（如阿尔茨海默氏症），或者对于我们自己的干细胞失控并分裂过快和/或产生错误类型的细胞的白血病等疾病特别重要。

Growing a new head, arm or leg is something humans obviously can’t do. But we do have cells that have some capacity to generate other cell types when they are needed, for example in response to cuts or bruises we are able to heal and replace damaged cells. In this study, a planarian worm will be used to understand the basic biology of stem cells, regeneration and healing. Planarians have a large number of stem cells which are capable of giving rise to every other cell type. For example, if a planarian is cut into small pieces, these cells will allow each piece of the worm to regenerate into a whole new, albeit smaller, worm. The intention of this research is to understand how the planarian worm’s stem cells are able to divide and give rise to the right cells at the right place in the new worm. If we can understand this process we may be closer to understanding our own capacity to regenerate lost or damaged cells. This type of research is particularly important for understanding diseases in which cells have been lost or damaged and new cells are needed (such as Alzheimers), or for diseases like leukemia where our own stem cells go haywire and divide too quickly and/or produce the wrong types of cells.