GPS cells ... chromosomes positioned according to function

Tariq Kabil

Scientists have discovered the presence of a chromosome positioning system (chromosomes) similar to the global positioning system "GPS" currently known, and it is a satellite navigation system that provides information about the location and timing anywhere on the earth, and provides important capabilities for users all over the world.

A research team from the Swiss University of Basel, in cooperation with scientists from Harvard University in the United States, has developed a new way to track chromosomes in individual cells of the slim lamb, one of the types of transparent roundworms that live in the wet soil environment.

In this way, they demonstrated that the chromosomes reorganize the fetus’s growth, and the results of this study were recently published in the journal Molecular Cell on February 26.

Spatial arrangement of chromosomes
Our body consists of a wide range of cells with various functions. Regardless of whether they are heart cells, liver, or nerves, they all contain the same genetic information.

If all the DNA molecules extend to a single cell, it will reach two meters in length, so the DNA must be densely packed to fit into the nucleus of the cell that does not exceed a few micrometers in size.

DNA strands are tightly wrapped and twisted to form space-saving structures, called chromosomes, and the method of packaging and DNA arrangement of chromosomes within the nucleus determines the activity of genes.

The reason cells evolve - differently in function and structure - is that only parts of the chromosomes are read, and this results in some genes being active while others are silent.

As for the activation of genes, the crucial role of the way genes are mobilized and their spatial organization in the cell nucleus is played, and the spatial arrangement of the genetic material within the cell nucleus plays an important role in the development of the organism.

Track individual chromosomes
In their study, the researchers led by Professor Susan Mango at Biosyntrum at the University of Basel tracked individual chromosomes in nematodes, and investigated their regulation during early fetal development.

The Mango team closely investigated the 3D structure, using a new technique, and they were able to track individual chromosomes during embryonic development, and to show that they were rearranging themselves during this early stage.

"With a new technique, we were able to track the spatial rearrangement of chromosomes in single cells at the beginning of embryogenesis ... the advantage of this method is that the cells and tissues remain completely intact," Mango told the news page of the Swiss University website Basel.

Functional properties
It is well known that regions of the chromosome with similar functional properties relate to one another and interact. This means that the chromosome ranges are separated into two parts, active and inactive.

"During the early embryonic development stage, the chromosomes are organized differently," says Ahlia Sawa, lead author of the study for the news page on the Swiss University website Basel.

"In the early fetus, it is organized into a unconventional, gravitational-like (iron weight) structure with inactive parts separated from an active central region."

Researchers have discovered that the nuclear plate (the protein network that lines the inner surface of the cell nucleus) is necessary to achieve this arrangement of gravity, and the nuclear plate is linked to inactive sections that extend to the chromosome.

Chromosomal reorganization
"At a later stage of fetal development, when germ cell layers develop, we actually see the separation known in active and inactive areas," says Mango.

"By using chromosome tracking, we were able to map the entire 3D chromosome, and we can show for the first time that the chromosomes are rearranging during early growth and development, a maturation process that requires the nuclear plate."

The correct structure of chromosomes is necessary to prevent developmental disorders, and the process of reorganization of the chromosomes is accompanied by cell growth and maturity, which represents a milestone in the development of the complex organism.

And of course the results of these recent studies can be applied to the stages of the development of human embryos to study growth strikes and genetic diseases during the development of the fetus, and the development of diagnostic methods and treatments for these diseases.