Abstract：
Cell size and growth are intimately related across the evolutionary scale, but whether cell size is important to attain maximal growth or fitness is still an open question. We show that growth rate is a non-monotonic function of cell volume, with maximal values around the critical size of wild-type yeast cells. The transcriptome of yeast and mouse cells undergoes a relative inversion in response to cell size, which we associate theoretically and experimentally with the necessary genome-wide diversity in RNA polymerase II affinity for promoters. Although highly expressed genes impose strong negative effects on fitness when the DNA/mass ratio is reduced, transcriptomic alterations mimicking the relative inversion by cell size strongly restrain cell growth. In all, our data indicate that cells set the critical size to obtain a properly balanced transcriptome and, as a result, maximize growth and fitness during proliferation.
摘要：
细胞大小和生长在整个进化尺度上密切相关，但是细胞大小对于获得最大的生长或健康是否重要仍然是一个悬而未决的问题。我们证明了生长速率是细胞体积的非单调函数，在野生型酵母细胞的临界大小附近具有最大值。酵母和小鼠细胞的转录组经历了响应细胞大小的相对倒置，我们将其理论上和实验上与RNA聚合酶II对启动子的亲和力中必要的全基因组多样性相关联。尽管当DNA/质量比降低时，高表达的基因会对适应性产生强烈的负面影响，模拟细胞大小相对反转的转录组改变强烈抑制细胞生长。总之,我们的数据表明，细胞设定临界大小以获得适当平衡的转录组，因此,在增殖过程中最大化生长和健身。
