Many fully developed metazoan tissues remain in a state of flux throughout life. During physiological cell turnover, older differentiated cells are typically eliminated by apoptosis and replaced by the division progeny of adult stem cells. Independently, each of these processes has been researched extensively, yet we know very little about how cell death and stem cell division are coordinated in adult organs. Freshwater planarians are an attractive model organism for research in this area. Not only do they undergo a very high rate of somatic cell turnover throughout life, but experimental tools are now available to study this process in vivo. Together, these attributes provide an opportunity to investigate the mechanisms, functions, and regulation of cell turnover in adult tissues.

中文翻译：

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细胞更新和成人组织动态平衡：从人类到涡虫。

许多完全发育的后生组织在整个生命中都保持着不断变化的状态。在生理细胞更新期间，较老的分化细胞通常被凋亡消除，并被成年干细胞的分裂后代所取代。独立地，对这些过程中的每一个进行了广泛的研究，但是我们对成人器官中细胞死亡和干细胞分裂如何协调的了解甚少。淡水浮游动物是该领域研究的一种有吸引力的模式生物。它们不仅在一生中经历很高的体细胞更新率，而且现在有实验工具可用于体内研究这一过程。这些属性共同为研究成人组织中细胞更新的机制，功能和调节提供了机会。