Studies show how the physical properties of the genome change before and after cell differentiation

A team of scientists have discovered that the composition of the human genome depends on the physics of various states of matter, such as liquids and solids. Findings that reveal how the physical properties of the genome change as cells change to perform specific functions help to better understand the disease and improve treatments for cancer and hereditary disorders. It shows a new way of creating.

The genome is a library of vital genetic information. Each cell contains the entire library, but uses only part of this information.

Only certain “books” are opened in special types of cells, such as white blood cells and neurons. That is, a book that contains information related to that feature. Researchers have long sought to find out how the genome manages these huge libraries, gives them access to the “books” they need, and stores unused books.

In a newly published study published in a journal Physical Review Letter, Researchers have shown how this happens inside the cell.

It was found that the used part of the genome is liquid and the unused part forms solid-like islands. These solid-like islands act as library bookshelves for books containing genes that are not currently in use, and the liquid genome portion acts like an “open book”, is easily accessible, and is of the cell. Used for life and function.

Alexandra Zidowska, New York University, Department of Physics, Principal Author and Associate Professor

The genetic information of the genome is encoded by a DNA molecule. Proper reading and processing of this information is important for human health and aging. In human cells, the genome containing the genetic code is housed in the cell nucleus. It stores about 2 meters of DNA, barely 10 micrometers in size, or about one-tenth the width of human hair.

To store such a huge amount of genetic information in such a small space, you need to pack it so that you can easily access each part of DNA, that is, each part of the genetic code, when you need it.

What was not well understood until now is how this information was stored and the role of physics in it.

To investigate this phenomenon, researchers, including New York University PhD candidates Iraj Eshghi and Jonah Eaton, compared cells before and after cell specialization.

Specifically, scientists have mapped the movement of the genome in the nucleus of mouse stem cells-not yet having special functions, but ready for any cell type, such as neurons or white blood cells. It differentiates into nerve cells before remapping the movement of the genome. In doing so, they created the first ever map of genomic movement before and after cell differentiation.

Here they found that stem cells kept their genome “open”, accessible like an open book, and had easy access to “gene pages.”

However, this mapping also showed that when a stem cell becomes a special cell, such as a neuron, the special cell has easy access to only part of the genome needed for that particular function. It cleans up unused parts of the genome on a “bookshelf”. This gives you more space for information that is being actively read and processed.

“These movements show exactly how the genome can be accessed at specific locations within the cell nucleus,” explains Zidovska. “Furthermore, these movements reveal the physical state of different parts of the genome, with the liquid part corresponding to loosely packed DNA and the solid-like part corresponding to tightly packed DNA gels. I will.

Genome packing in these different states directly affects the accessibility of the genome. In contrast to solid-like parts, liquid parts are accessible. Surprisingly, this tissue relies on the condensed matter physics of various states of liquid and solid. “

“By measuring the movement of different parts of the genome, we were able to show different physical properties of different parts of the genome and understand the composition of the genome, the” library system “of cells,” she said. Adds.

Researchers point out that a proper cell filing system is essential for human health.

“Given the huge number of cell types in the human body, lost or misplaced books in this cell library can lead to information loss or unnecessary information. It is sexual and can lead to developmental disorders, hereditary disorders, and even distress such as cancer, ”explains Zidovska.

“Therefore, clarifying how the genome is organized in the cell nucleus is important in understanding these conditions and diseases. Moreover, such knowledge is the future of such diseases. It can be useful in designing treatments and diagnostics. “