The decline of tissue regenerative potential with the loss of stem cell function is a hallmark of mammalian aging. We study Botryllus schlosseri, a colonial chordate which exhibits robust stem cell-mediated regeneration capacities throughout life. Larvae, derived by sexual reproduction and chordate development, metamorphose to clonal founders that undergo weekly formation of new individuals by budding from stem cells. Individuals are transient structures which die through massive apoptosis, and successive buds mature to replicate an entire new body. As a result, their stem cells, which are the only self-renewing cells in a tissue, are the only cells which remain through the entire life of the genotype and retain the effects of time. During aging, a significant decrease in the colonies’ regenerative potential is observed and both sexual and asexual reproductions will eventually halt. When a parent colony is experimentally separated into a number of clonal replicates, they frequently undergo senescence simultaneously, suggesting a heritable factor that determines lifespan in these colonies. The availability of the recently published B. schlosseri genome coupled with its unique life cycle features promotes the use of this model organism for the study of the evolution of aging, stem cells, and mechanisms of regeneration.

中文翻译：

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Botryllus schlosseri，一种用于研究衰老、干细胞和再生机制的新兴模型

随着干细胞功能的丧失，组织再生潜力的下降是哺乳动物衰老的标志。我们研究 Botryllus schlosseri，一种殖民地脊索动物，在整个生命过程中都表现出强大的干细胞介导的再生能力。通过有性繁殖和脊索动物发育衍生的幼虫蜕变成克隆建立者，每周通过干细胞出芽形成新个体。个体是短暂的结构，通过大量细胞凋亡而死亡，而连续的芽成熟以复制一个全新的身体。因此，它们的干细胞是组织中唯一的自我更新细胞，也是唯一能在基因型的整个生命周期中保留并保持时间影响的细胞。在衰老过程中，观察到菌落的再生潜力显着下降，有性和无性繁殖最终都会停止。当一个亲本菌落通过实验被分离成许多克隆复制品时，它们经常同时经历衰老，这表明决定这些菌落寿命的遗传因素。最近发表的 B. schlosseri 基因组的可用性及其独特的生命周期特征促进了这种模式生物用于研究衰老、干细胞和再生机制的进化。