The "sheath-like" structure accounts for 47% of each chromosome.

In each nucleocle, DNA molecules form chromosomes closely around histoproteins.
but new research has found that chromosomes contain more than 25,000 genes, and scientists have found that a mysterious "sheath-like" structure accounts for 47 percent of each chromosome.
more than a century, our understanding of chromosomes is based on the assumption that chromosomes are made up of DNA complexes and a histone called a nuclear chromosome in each cell nucleosis.
Chromosomes have been the subject of research since they were discovered in 1882, but details about their internal structure have not been worked out, in large part because chromosomes are completely invisible in the nucleation of cells unless they are dividing.
when cells divide by subtracting or silky division, chromosomes accumulate more closely, causing chromosomes to become "super-helixes" that can be observed under a microscope.
most of what researchers know about chromosomes is observed in cell division, but since we can only observe them in certain situations, we have not been able to obtain a complete image of chromosomes.
To improve their ability to observe the internal structure of chromosomes, researchers at the University of Edinburgh in Scotland have developed a new method called 3D-CLEM, which combines optical and electron microscopes with computational model software to produce high-resolution 3D images of 46 chromosomes in humans.
after modeling the length, width, surface area, volume, and DNA density of all normal human chromosomes, they found something important in our understanding of the internal structure of chromosomes.
biologist Daniel Booth said: "Defining all 46 human chromosomes forces us to reconsider the idea that chromosomes are almost entirely made up of chromosomes, a hypothesis that has never been challenged in 100 years.
, chromosomes accounted for only 53 to 70 percent of all chromosome components.
another structure called periphery, which accounts for 30 to 47 percent of chromosomes, researchers have observed in the past, but it's not clear how many they have.
means that for any chromosome, DNA and its support proteins may account for only half of all ingredients.
The first application of 3D-CLEM analysis led to the remarkable and surprising conclusion that a large part of the total volume of a silky split chromosome is not made up of chromosomes, but by the perimeter of chromosomes," they wrote in the paper.
at this stage, people still don't understand what the structure's specific function is, but the researchers suspect that it may function like some kind of "slug" that isolates chromosomes from each other as cells divide.
this is supported by past studies that have shown that this structure forms partly from the Ki-67 protein.
Ki-67 is a sign of cell proliferation, binding to the surface of the chromosome to separate the sister chromosomal monoplate.
if this is really the function of chromosome crucibles, it means that this structure plays an important role in preventing errors when cells divide.
In addition to function, there are many things we don't know about this mysterious structure, we're not sure if it works like a liquid or solid membrane, or how it affects the structural changes of chromosomes as cells divide.
, it looks like a return to the most basic question of cellular composition.
now we have to rethink how chromosomes are made and how they are isolated when cells divide, because these genetic materials are thickly covered with other substances," said Bill Earnshaw, one of the team members on the study.
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