The critical size is set at a single-cell level by growth rate to attain homeostasis and adaptation
The critical size is set at a single-cell level by growth rate to attain homeostasis and adaptation
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DOI：
10.1038/ncomms2015
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发表时间：
2012-08-01
影响因子：
16.6
通讯作者：
Aldea, Marti
中科院分区：
文献类型：
--
作者：
Ferrezuelo, Francisco;Colomina, Neus;Aldea, Marti
假设芽殖酵母细胞只有在达到外部条件设定的临界大小后才会触发启动并进入细胞周期。然而，与细胞大小控制的确定性模型相反，即使在恒定条件下，开始时的细胞体积也显示出很大的个体变异性。在这里，我们表明，细胞大小在开始是鲁棒设置在一个单细胞水平的体积增长率在G1，这解释了观察到的变异性。我们发现，这种生长速率依赖的sizer是紧密的硬连线到启动网络和Ydj1伴侣是设置细胞大小作为一个函数的个人生长速率的关键。数学建模和实验数据表明，生长速率依赖型sizer足以确保大小的稳态，作为一个显着的优势，在刚性sizer机制，它减少了G1长度的噪音，并提供了一个直接的解决方案，在人口水平的外部条件的大小适应。
Budding yeast cells are assumed to trigger Start and enter the cell cycle only after they attain a critical size set by external conditions. However, arguing against deterministic models of cell size control, cell volume at Start displays great individual variability even under constant conditions. Here we show that cell size at Start is robustly set at a single-cell level by the volume growth rate in G1, which explains the observed variability. We find that this growth-rate-dependent sizer is intimately hardwired into the Start network and the Ydj1 chaperone is key for setting cell size as a function of the individual growth rate. Mathematical modelling and experimental data indicate that a growth-rate-dependent sizer is sufficient to ensure size homeostasis and, as a remarkable advantage over a rigid sizer mechanism, it reduces noise in G1 length and provides an immediate solution for size adaptation to external conditions at a population level.