14 DAY TRIAL // In a new and quite mind-boggling paper in the journal Cell Reports, scientists with Sweden's Lund University argue that the genomic residue of viral infections that we humans experienced a long, long time ago is the reason we – well, some of us – are super smart when compared to other mammals.
Now don't go clicking off this article just yet. It really isn't as complicated as it sounds. Thus, what the researchers mean by this fancy-sounding genomic residue of long-gone viral infections is inherited viruses that are millions of years old and that we all carry in our body.
That’s right, endogenous retroviruses account for as much as 4.9% of the human genome and are also included in the genetic makeup of plenty of other animals. For quite a while, these inherited viruses were considered to be junk DNA that just sat around doing nothing.
Apparently, inherited viruses are actually quite useful
In their report in the journal Cell Reports, the Lund University scientists explain that, having carried out a series of laboratory experiments, they found that our millions of years old inherited viruses might just be the reason we evolved to be smarter than other animals.
More precisely, the researchers say that this genomic residue of ancient viral infections serves to regulate the human brain's most basic functions by helping establish when certain genes get to be expressed. In doing so, it helps turn the human brain into the complex machinery that we know it to be.
“We believe that the role of retroviruses can contribute to explaining why brain cells in particular are so dynamic and multifaceted in their function. It may also be the case that the viruses’ more or less complex functions in various species can help us to understand why we are so different,” says study leader Johan Jakobsson.
The discovery could revolutionize healthcare
Writing in the journal Cell Reports, researcher Johan Jakonsson and colleagues explain that, as shown by several studies carried out over the years, plenty of the diseases documented to affect the human brain stem from underlying genetic factors.
The thing is that, when looking for these genetic factors, scientists focused on genes that they are familiar with alone. Simply put, the so-called junk DNA does not get all that much attention, if any. If it is indeed true that inherited viruses influence brain development, they should be investigated as well.
The Lund University specialists now saying that endogenous retroviruses influence processes in the brain, and in doing so they contribute to the intelligence that defines our species, argue that, if they are right, the study of our viral genomic residue could help treat various conditions that affect the human brain.
“The image of the brain becomes more complex, but the area in which to search for errors linked to diseases with a genetic component, such as neurodegenerative diseases, psychiatric illness and brain tumours, also increases,” explains researcher Johan Jakobsson.