Modern biological techniques such as Hi-C permit one to measure probabilities that different chromosomal regions are close in space. These probabilities can be visualized as matrices called contact maps. In this paper, we introduce a multifractal analysis of chromosomal contact maps. Our analysis reveals that Hi-C maps are bifractal, i.e., complex geometrical objects characterized by two distinct fractal dimensions. To rationalize this observation, we introduce a model that describes chromosomes as a hierarchical set of nested domains and we solve it exactly. The predicted multifractal spectrum is in excellent quantitative agreement with experimental data. Moreover, we show that our theory yields a more robust estimation of the scaling exponent of the contact probability than existing methods. By applying this method to experimental data, we detect subtle conformational changes among chromosomes during differentiation of human stem cells.
Bifractal nature of chromosome contact maps / S. Pigolotti, M.H. Jensen, Y. Zhan, G. Tiana. - In: PHYSICAL REVIEW RESEARCH. - ISSN 2643-1564. - 2:4(2020), pp. 043078.1-043078.9.
|Titolo:||Bifractal nature of chromosome contact maps|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2020|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1103/PhysRevResearch.2.043078|
|Appare nelle tipologie:||01 - Articolo su periodico|