The size of the nucleus increases as yeast cells grow
The size of the nucleus increases as yeast cells grow
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DOI：
10.1091/mbc.e06-10-0973
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发表时间：
2007-09-01
影响因子：
3.3
通讯作者：
Futcher, Bruce
中科院分区：
文献类型：
--
作者：
Jorgensen, Paul;Edgington, Nicholas P.;Futcher, Bruce
目前尚不清楚细胞核的体积是如何确定的，也不知道核体积与细胞体积之比（N/C）如何确定。在这里，我们测量了芽殖酵母酿酒酵母生长细胞的细胞核大小。对不同细胞大小的酵母突变株的分析表明，平均核体积与平均细胞体积的比例相当一致，核体积接近细胞体积的7%。在单细胞水平上，通过三种不同的显微镜方法确定，在生长的野生型细胞中，核和细胞大小密切相关。即使在g1期，核体积也在增长，尽管它的增长速度不如整个细胞体积快。DNA含量似乎对细胞核大小没有任何直接的影响，在s期细胞核大小没有急剧增加。核大小的维持不需要持续生长或核糖体生物发生，因为饥饿和雷帕霉素治疗对核大小几乎没有直接影响。用leptomycin B阻断新核糖体亚基的核输出，以及其他蛋白质和rna，对核大小也没有明显影响。核扩张现在必须考虑到出芽酵母生长和分裂的概念和数学模型中。这些结果对酵母细胞生长过程中使细胞核扩大的未知力量提出了疑问。
It is not known how the volume of the cell nucleus is set, nor how the ratio of nuclear volume to cell volume (N/C) is determined. Here, we have measured the size of the nucleus in growing cells of the budding yeast Saccharomyces cerevisiae. Analysis of mutant yeast strains spanning a range of cell sizes revealed that the ratio of average nuclear volume to average cell volume was quite consistent, with nuclear volume being similar to 7% that of cell volume. At the single cell level, nuclear and cell size were strongly correlated in growing wild-type cells, as determined by three different microscopic approaches. Even in G1-phase, nuclear volume grew, although it did not grow quite as fast as overall cell volume. DNA content did not appear to have any immediate, direct influence on nuclear size, in that nuclear size did not increase sharply during S-phase. The maintenance of nuclear size did not require continuous growth or ribosome biogenesis, as starvation and rapamycin treatment had little immediate impact on nuclear size. Blocking the nuclear export of new ribosomal subunits, among other proteins and RNAs, with leptomycin B also had no obvious effect on nuclear size. Nuclear expansion must now be factored into conceptual and mathematical models of budding yeast growth and division. These results raise questions as to the unknown force(s) that expand the nucleus as yeast cells grow.