Gaussian fluctuation of the diffusion exponent of virus capsid in a living cell nucleus

TL;DR

This paper investigates the Gaussian nature of diffusion exponent fluctuations of virus capsids in cell nuclei, using a maximum-entropy approach to explain experimental observations and analyze long-term deviations.

Contribution

It applies a maximum-entropy principle to model the Gaussian fluctuation distribution of virus diffusion exponents in cell nuclei, extending previous work to long-term behavior.

Findings

Gaussian distribution of local fluctuations is derived theoretically.

Long-term fluctuation distribution deviates from Gaussian form.

Large number of local areas supports the statistical model.

Abstract

In their work [Proc. Natl. Acad. Sci. USA 112 (2015) E5725], Bosse et al. experimentally showed that virus capsid exhibits not only normal diffusion but also anomalous diffusion in nucleus of a living cell. There, it was found that the distribution of fluctuations of the diffusion exponent characterizing them takes the Gaussian form, which is, quite remarkably, the same form for two different types of the virus. This suggests high robustness of such fluctuations. Here, the statistical property of local fluctuations of the diffusion exponent of the virus capsid in the nucleus is studied. A maximum-entropy-principle approach (originally proposed for a different virus in a different cell) is applied for obtaining the fluctuation distribution of the exponent. Largeness of the number of blocks identified with local areas of interchromatin corrals is also examined based on the experimental data. It is shown that the Gaussian distribution of the local fluctuations can be derived, in accordance with the above form. In addition, it is quantified how the fluctuation distribution on a long time scale is different from the Gaussian distribution.