Nepal Sudip, Kumar Pradeep
Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA.
Phys Rev E. 2018 May;97(5-1):052411. doi: 10.1103/PhysRevE.97.052411.
Phenotypic switching is one of the mechanisms by which bacteria thrive in ever changing environmental conditions around them. Earlier studies have shown that the application of steady high hydrostatic pressure leads to stochastic switching of mesophilic bacteria from a cellular phenotype having a normal cell cycle to another phenotype lacking cell division. Here, we have studied the dynamics of this phenotypic switching with fluctuating periodic pressure using a set of experiments and a theoretical model. Our results suggest that the phenotypic switching rate from high-pressure phenotype to low-pressure phenotype in the reversible regime is larger as compared to the switching rate from low-pressure phenotype to high-pressure phenotype. Furthermore, we find that even though the cell division and elongation are presumably regulated by a large number of genes the underlying physics of the dynamics of stochastic switching at high pressure is captured reasonably well by a simple two-state model.
表型转换是细菌在其周围不断变化的环境条件下得以生存的机制之一。早期研究表明，施加稳定的高静水压力会导致嗜温细菌从具有正常细胞周期的细胞表型随机转换为另一种缺乏细胞分裂的表型。在此，我们通过一系列实验和理论模型研究了这种在波动周期性压力下的表型转换动力学。我们的结果表明，在可逆状态下，从高压表型到低压表型的表型转换率比从低压表型到高压表型的转换率更大。此外，我们发现，尽管细胞分裂和伸长可能受大量基因调控，但一个简单的双态模型就能很好地捕捉高压下随机转换动力学的基本物理原理。
