Spin-echo small-angle neutron scattering study of the structure organization of the chromatin in biological cell

E G Iashina,W G Bouwman,S V Grigoriev,M V Filatov,C P Duif

doi:10.1088/1742-6596/862/1/012010

Abstract

Spin-echo small-angle scattering (SESANS) technique is a method to measure the structure of materials from nano- to micrmeter length scales. This method could be important for studying the packaging of DNA in the eukaryotic cell. We measured the SESANS function from chicken erythrocyte nuclei which is well fitted by the exponential function G(z) = exp(−z/ξ), where ξ is the correlation length of a nucleus (in experimental data ξ = 3, 3 μm). The exponential decay of G(z) corresponds to the logarithmic pair correlation function γ(r) = ln(ξ/r). As the sensitivity of the SESANS signal depends on the neutron wavelength, we propose the SESANS setup with the changeable wavelength in the range from 2 to 12 Å. Such option allows one to study in great detail the internal structure of the biological cell in the length scale from 10−2μm to 10 μm.

Highlights

It is well known that the cell is the basic structural and functional unit of all known living organisms
The large-scale chromatin organization in interphase nuclei is fundamentally different from the small-scale chromatin structure [1,2,3,4,5,6]
In the present study we report the result of the spin-echo SANS measurements from chicken erythrocyte nuclei. Analyzing these results we propose to optimize the parameters of the Spin-echo small-angle scattering (SESANS) setup in order to obtain the full information on the pair correlation function of the chromatin inside a biological cell

Summary

Introduction

It is well known that the cell is the basic structural and functional unit of all known living organisms. The cell nucleus acts like the control center of the cell In this nucleus, a complex of macromolecules can be found which consists of DNA and proteins is called the chromatin. Chromatin is a double-helical structure of DNA. One of the most exciting questions that scientists are trying to answer is how DNA is packed inside the nucleus of a cell. Nowadays the multiscale fractal model of DNA arrangement inside the nuclei [3, 4] is the most promising to explain this mystery. Experimental proof of this theory is complicated firstly

Present address

Findings

Conclusions