Abstract:
All cells are subject to geometric constraints, such as surface area-to-volume (SA/V) ratio, that impact cell functions and force biological adaptations. Like the SA/V ratio of a sphere, it is generally assumed that the SA/V ratio of cells decreases as cell size increases. Here, we investigate this in near-spherical mammalian cells using single-cell measurements of cell mass and surface proteins, as well as imaging of plasma membrane morphology. We find that the SA/V ratio remains surprisingly constant as cells grow larger. This observation is largely independent of the cell cycle and the amount of cell growth. Consequently, cell growth results in increased plasma membrane folding, which simplifies cellular design by ensuring sufficient membrane area for cell division, nutrient uptake and deformation at all cell sizes.
摘要:
所有单元都受到几何约束,例如表面积与体积比(SA/V),影响细胞功能并迫使生物适应。就像球体的SA/V比一样,通常假设细胞的SA/V比率随着细胞大小的增加而降低。这里,我们使用细胞质量和表面蛋白的单细胞测量在近球形哺乳动物细胞中进行研究,以及质膜形态的成像。我们发现SA/V比率随着细胞生长变大而令人惊讶地保持恒定。这种观察在很大程度上与细胞周期和细胞生长的量无关。因此,细胞生长导致增加的质膜折叠,通过确保细胞分裂的足够的膜面积来简化细胞设计,所有细胞大小的营养吸收和变形。