Nuclear size scales with cell size across a wide range of cell types. The mechanism by which this scaling is maintained in growing cells remains unclear. Here, we investigate the mechanism of nuclear size homeostasis in the simple eukaryote fission yeast, by monitoring the recovery of aberrant nuclear volume to cell volume (N/C) ratios following perturbation. We demonstrate that both high and low N/C ratios correct rapidly, maintaining nuclear size homeostasis. We assess the kinetics of nuclear and cellular growth and of N/C ratio correction, and demonstrate that nuclear and cellular growth rates are not directly coupled. We propose that the mechanism underlying nuclear size homeostasis involves multiple limiting factors implicated in processes including nucleocytoplasmic transport, lipid biogenesis and RNA processing. We speculate that these link cellular size increases to changes in nuclear contents, which in turn lead to changes in nuclear membrane surface area. Our study reveals that there is rapid nuclear size homeostasis in cells, informing understanding of nuclear size control and size homeostasis of other membrane-bound organelles.

中文翻译：

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体内平衡机制迅速校正了异常核细胞质比例，从而保持了裂变酵母中的核大小。

核的大小随细胞类型的广泛而变化。在生长中的细胞中维持这种缩放的机制仍不清楚。在这里，我们通过监测扰动后异常核体积与细胞体积（N / C）比的恢复，研究了简单的真核生物裂变酵母中核大小稳态的机制。我们证明，高和低的N / C比都可以迅速纠正，并保持核尺寸的稳态。我们评估核和细胞生长和N / C比校正的动力学，并证明核和细胞的生长速率不直接耦合。我们建议潜在的核大小稳态机制涉及多个限制因素牵连过程包括核质运输，脂质生物发生和RNA加工。我们推测这些链接细胞的大小会增加，以改变核含量，进而导致核膜表面积的变化。我们的研究表明，细胞中存在快速的核尺寸稳态，这有助于了解其他膜结合细胞器的核尺寸控制和尺寸稳态。