Hydra represents a unique model system for the study of senescence, with the opportunity for the comparison of non-aging and induced senescence. Hydra maintains three stem cell lineages, used for continuous tissue morphogenesis and replacement. Recent work has elucidated the roles of the insulin/IGF-1 signaling target FoxO, of Myc proteins, and of PIWI proteins in Hydra stem cells. Under laboratory culture conditions, Hydra vulgaris show no signs of aging even under long-term study. In contrast, Hydra oligactis can be experimentally induced to undergo reproduction-associated senescence. This provides a powerful comparative system for future studies.

中文翻译：

---

Hydraas 是一种易于处理、寿命长的衰老模型系统

Hydra 代表了一个独特的衰老研究模型系统，有机会比较非衰老和诱导衰老。Hydra 维持三个干细胞谱系，用于连续的组织形态发生和替换。最近的工作阐明了胰岛素/IGF-1 信号靶点 FoxO、Myc 蛋白和 PIWI 蛋白在 Hydra 干细胞中的作用。在实验室培养条件下，即使在长期研究下，Hydra vulgaris 也没有老化迹象。相比之下，Hydra oligactis 可以通过实验诱导经历与繁殖相关的衰老。这为未来的研究提供了一个强大的比较系统。