Have you ever wondered why you have hair on your feet but not on your feet?
Or why do we get a lot of hair on the head, but not one strand of hair in the palm of our hand?
That question has been a problem that has been delayed for doctors, researchers and other scientists from the complex machinery of the human body.
For decades, science was limited to considering that it was a evolutionary nature some animals, but the physiological explanation of how it was produced to date is a question.
Scientists from the University of Pennsylvania School of Medicine investigated this "mystery" for years and now claim to have found the answer.
Studies published in the journal Cell Report, indicating that "the culprit" is from not We get hair in certain parts of our body is a special type of molecule, for more signals, protein.
According to researchers, this is about Dickkopf 2 (DKK2), which blocks the so-called "WNT signaling pathway", a cellular channel that is, among other things, responsible for triggering hair growth.
"In this study, we showed that skin in areas without hair naturally produced inhibitors that prevented WNT from doing their work," he told the magazine. Newsweek Sarah E. Millar, one of the authors of the investigation.
"We know that WNT signaling is very important for the development of hair follicles, blocking it from causing hairless skin and activating it to cause the formation of more hair," he said.
But why do some animals have hair in most of their bodies and others don't?
This study shows that it was, as has been known for years, about evolutionary adaptation.
This study considers that certain animals evolved to produce DKK2 in certain parts of their bodies help them to better survive in their environment.
So, for example, a hairless hand will function more for holding instruments or other tasks, while the absence of villi on your feet will help you walk better.
However, in cold climates, it would be better if coated, as in the case of polar bears.
To reach this conclusion, the team analyzed the skin of mouse feet (which, like humans, did not have hair on their plants) and compared them to other animals that did it, like rabbits.
When comparing DKK2 levels between two species, they found that the amount of protein was far less in the skin of animals that had fur on the soles of their feet.
Meanwhile, the molecular level is much higher in areas where hair does not grow than in the hairiest regions.
This study shows that not in these areas there are no WNT signaling pathways, hair generators, but that proteins block them.
Now, the researchers hope these findings can be used for new research on hair growth, to treat several diseases or for future care to people who have suffered burns or severe accidents.