Petralia Ronald S, Mattson Mark P, Yao Pamela J
Advanced Imaging Core, NIDCD/NIH, Bethesda, MD 20892, United States.
Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, United States.
Ageing Res Rev. 2014 Jul;16:66-82. doi: 10.1016/j.arr.2014.05.003. Epub 2014 Jun 5.
Here we review the examples of great longevity and potential immortality in the earliest animal types and contrast and compare these to humans and other higher animals. We start by discussing aging in single-celled organisms such as yeast and ciliates, and the idea of the immortal cell clone. Then we describe how these cell clones could become organized into colonies of different cell types that lead to multicellular animal life. We survey aging and longevity in all of the basal metazoan groups including ctenophores (comb jellies), sponges, placozoans, cnidarians (hydras, jellyfish, corals and sea anemones) and myxozoans. Then we move to the simplest bilaterian animals (with a head, three body cell layers, and bilateral symmetry), the two phyla of flatworms. A key determinant of longevity and immortality in most of these simple animals is the large numbers of pluripotent stem cells that underlie the remarkable abilities of these animals to regenerate and rejuvenate themselves. Finally, we discuss briefly the evolution of the higher bilaterians and how longevity was reduced and immortality lost due to attainment of greater body complexity and cell cycle strategies that protect these complex organisms from developing tumors. We also briefly consider how the evolution of multiple aging-related mechanisms/pathways hinders our ability to understand and modify the aging process in higher organisms.
在此，我们回顾最早的动物类型中长寿和潜在永生的例子，并将其与人类及其他高等动物进行对比和比较。我们首先讨论单细胞生物（如酵母和纤毛虫）的衰老以及永生细胞克隆的概念。然后我们描述这些细胞克隆如何组织成不同细胞类型的群体，从而形成多细胞动物生命。我们考察所有基础后生动物类群中的衰老和长寿情况，包括栉水母、海绵动物、扁盘动物、刺胞动物（水螅、水母、珊瑚和海葵）以及粘孢子虫。接着我们转向最简单的两侧对称动物（具有头部、三个体细胞层和两侧对称），即扁形动物门的两个纲。在大多数这些简单动物中，长寿和永生的一个关键决定因素是大量的多能干细胞，这些干细胞是这些动物具有显著再生和恢复活力能力的基础。最后，我们简要讨论高等两侧对称动物的进化，以及由于身体复杂性增加和细胞周期策略（保护这些复杂生物体不发生肿瘤）导致长寿减少和永生丧失的情况。我们还简要考虑多种与衰老相关的机制/途径的进化如何阻碍我们理解和改变高等生物衰老过程的能力。
