June 04, 2021
Bulletin interne de l'Institut Pasteur
An imaging and modeling approach to characterize the structure of DNA in human cells
The structure of DNA and chromosomes is a major focus of research, but still holds a number of mysteries. Scientists from the Institut Pasteur and the CNRS have developed a new method for quantifying chromatin loops and observing chromosomes at high resolution.
In our cells, DNA is coiled up many times, enabling it to fit into the cell nucleus, which is approximately 200,000 times smaller than the length of the uncoiled DNA. DNA is initially coiled around proteins known as histones, to form a structure called the nucleosome. Nucleosomes in turn form a structure known as chromatin fiber. We have known for some years that chromatin fiber forms loops that are maintained by a molecule complex called cohesin. These chromatin loops help structure chromosomes and play an important role in basic genome functions such as gene expression.