Denton Jai A, Ghosh Atiyo, Marquez-Lago Tatiana T
Integrative Systems Biology Unit, Okinawa Institute of Science and Technology, Onna-son, Okinawa, 904-0495, Japan.
PLoS One. 2015 Oct 15;10(10):e0139443. doi: 10.1371/journal.pone.0139443. eCollection 2015.
The asymmetrical inheritance of plasmid DNA, as well as other cellular components, has been shown to be involved in replicative aging. In Saccharomyces cerevisiae, there is an ongoing debate regarding the mechanisms underlying this important asymmetry. Currently proposed models suggest it is established via diffusion, but differ on whether a diffusion barrier is necessary or not. However, no study so far incorporated key aspects to segregation, such as dynamic morphology changes throughout anaphase or plasmids size. Here, we determine the distinct effects and contributions of individual cellular variability, plasmid volume and moving boundaries in the asymmetric segregation of plasmids. We do this by measuring cellular nuclear geometries and plasmid diffusion rates with confocal microscopy, subsequently incorporating this data into a growing domain stochastic spatial simulator. Our modelling and simulations confirms that plasmid asymmetrical inheritance does not require an active barrier to diffusion, and provides a full analysis on plasmid size effects.
质粒DNA以及其他细胞成分的不对称遗传已被证明与复制性衰老有关。在酿酒酵母中，关于这种重要不对称性背后的机制存在持续的争论。目前提出的模型表明它是通过扩散建立的，但在是否需要扩散屏障方面存在分歧。然而，迄今为止，尚无研究纳入分离的关键方面，例如整个后期的动态形态变化或质粒大小。在这里，我们确定了个体细胞变异性、质粒体积和移动边界在质粒不对称分离中的不同影响和贡献。我们通过共聚焦显微镜测量细胞核几何形状和质粒扩散速率来做到这一点，随后将这些数据纳入一个不断发展的域随机空间模拟器中。我们的建模和模拟证实，质粒不对称遗传不需要主动的扩散屏障，并对质粒大小效应进行了全面分析。
