Center for Quantitative Biology, and the State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.
Aging Cell. 2012 Aug;11(4):599-606. doi: 10.1111/j.1474-9726.2012.00821.x. Epub 2012 May 17.
Budding yeast has served as an important model organism for aging research, and previous genetic studies have led to the discovery of conserved genes/pathways that regulate lifespan across species. However, the molecular causes of aging and death remain elusive, because it is very difficult to directly observe the cellular and molecular events accompanying aging in single yeast cells by the traditional approach based on micromanipulation. We have developed a microfluidic system to track individual mother cells throughout their lifespan, allowing automated lifespan measurement and direct observation of cell cycle dynamics, cell/organelle morphologies, and various molecular markers. We found that aging of the wild-type cells is characterized by an increased general stress and a progressive lengthening of the cell cycle for the last few cell divisions; these features are much less apparent in the long-lived FOB1 deletion mutant. Following the fate of individual cells revealed that there are different forms of cell death that are characterized by different terminal cell morphologies, and associated with different levels of stress and lifespan. We have identified a molecular marker - the level of the expression of Hsp104, as a good predictor for the lifespan of individual cells. Our approach allows detailed molecular phenotyping of single cells in the process of aging and thus provides new insight into its mechanism.
芽殖酵母一直是衰老研究的重要模式生物，先前的遗传研究已经发现了调节不同物种寿命的保守基因/途径。然而，衰老和死亡的分子原因仍然难以捉摸，因为通过传统的基于微操作的方法，很难直接观察单个酵母细胞中伴随衰老的细胞和分子事件。我们开发了一种微流控系统来跟踪单个母细胞的整个生命周期，从而能够自动测量寿命并直接观察细胞周期动态、细胞/细胞器形态以及各种分子标记。我们发现，野生型细胞的衰老特征是普遍应激增加，以及在最后几次细胞分裂中细胞周期逐渐延长；在长寿的 FOB1 缺失突变体中，这些特征就不那么明显。跟踪单个细胞的命运揭示了存在不同形式的细胞死亡，其特征是不同的终末细胞形态，并且与不同程度的应激和寿命相关。我们已经确定了一种分子标记——Hsp104 的表达水平，它可以很好地预测单个细胞的寿命。我们的方法允许对衰老过程中的单个细胞进行详细的分子表型分析，从而为其机制提供了新的见解。
