by Ivan, February 2017
As it turns out, there’s more to chromosomes than just DNA.
Scientists believed that inside of the nucleus of every cell, DNA molecules are elaborately packed around proteins referred to as histones in order to form chromosomes. We’ve believed for over a century that chromosomes were made from a complex of DNA and histone proteins referred to as chromatin, built inside the nucleus of each cell. Chromatin is the substance in chromosomes which contains the building blocks of life: protein, RNA, and DNA.
However, a new study has proven that there’s much more to chromosomes than the 25,000 genes they contain.
Scientists have recently discovered that there is a mysterious ‘sheath-like’ structure which accounts up to 47% of every chromosome. Researchers suggest it may keep chromosomes isolated from one another during the key process of cell division.
“The imaging technique we have developed to study chromosomes is truly groundbreaking. Defining the structure of all 46 human chromosomes for the first time has forced us to reconsider the idea that they are composed almost exclusively of chromatin, an assumption that has gone largely unchallenged for almost 100 years,” says one of the team, biologist Daniel Booth.
In fact, most of what scientists know about chromosomes was found by observing them during cell division. However, since we can only observe chromosomes under certain conditions, scientists have only had access to an incomplete picture of what chromosomes look like and ultimately are.
“We now have to re-think how chromosomes are built and how they segregate when cells divide since the genetic material is covered by this thick layer of other material,” says Professor Bill Earnshaw of the School of Biological Sciences.
At the moment, the leading ‘theory’ seems to be that this ‘mystery structure’ serves as some sort of sheath that keeps chromosomes separated during a process known as mitosis, however, this has yet to be proven by experts. This discovery raises numerous questions regarding the building blocks of life and origin of man. Is it possible that this mysterious structure is in fact some sort of “alien ingredient” that has set humans on our ‘modern’ genetic trajectory?
What if this secret material possesses another role, which has yet to be discovered?
Journal reference: Molecular Cell
Provided by: University of Edinburgh
Stillness in the Storm Editor’s note: Did you find a spelling error or grammar mistake? Do you think this article needs a correction or update? Or do you just have some feedback? Send us an email at [email protected]. Thank you for reading.
Minor grammar corrections were made to this article.