How adult stem cells maintain self-renewing tissues is in vivo commonly assessed by analysing clonal data from cell lineage tracing assays. To identify strategies of stem cell self-renewal requires that different models of stem cell fate choice predict sufficiently different clonal statistics. Here we show that models of cell fate choice can, in homeostatic tissues, be categorized by exactly two 'universality classes', whereby models of the same class predict, under asymptotic conditions, the same clonal statistics. Those classes relate to generalizations of the canonical asymmetric vs. symmetric stem cell self-renewal strategies and are differentiated by a conservation law. Therefore, self-renewal strategies of the same universality class cannot be distinguished under asymptotic conditions, whereas models of different classes can be distinguished by simple means. However, asymptotic conditions for universality are not always fulfilled in nature, which poses both opportunities and pitfalls for conclusions drawn about stem cell self-renewal strategies.

中文翻译：

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克隆动力学的普遍性对识别干细胞自我更新策略提出了基本限制

成年干细胞如何维持自我更新的组织通常是在体内通过分析细胞谱系示踪分析的克隆数据来评估的。为了确定干细胞自我更新的策略，需要不同的干细胞命运选择模型预测足够不同的克隆统计数据。在这里，我们表明，在稳态组织中，细胞命运选择的模型可以按正好两个“大学类”进行分类，从而在渐近条件下，同一类的模型可以预测相同的克隆统计数据。这些类别涉及规范的不对称与对称干细胞自我更新策略的概括，并通过守恒定律加以区分。因此，在渐近条件下，无法区分相同普遍性类别的自我更新策略，而不同类别的模型可以通过简单的方法加以区分。然而，普遍性的渐近条件并不总是在自然界中得到满足，这为关于干细胞自我更新策略的结论既带来了机遇，也带来了陷阱。