Ever wonder why humans aren't furry?
In the winter, I'm jealous of dogs and cats. They basically have warm blankets attached to their skin. I am, on the other hand, nearly entirely hairless.
Some scientists also found this curious. So they examined DNA on palms to uncover the connection between genes and hair growth. They found one protein, Dickkopf 2, that they thought may make hair grow. But to their surprise, it had the opposite effect: it stopped hair from growing.“Based on some published data, we were initially expecting that DKK2 might play a role in generating the pattern of hair follicles in hairy skin, which proved not to be the case,” Sarah Millar, the study's co-author, told Inverse. “Instead, we found that it has an unexpected function in establishing areas of hairless skin.”
The scientists found a lot of DKK2 on the bottoms of mice feet, which are hairless. Rabbits, unlike mice and humans, have hair on the bottoms of their feet. They don't have much DKK2 there.
To test this theory, the scientists genetically got rid of the protein on mice feet somehow, and the mice started growing hair there.
It makes sense, if you think about it. Most mammals are pretty hairy. Humans must have lost the hair at some point on the evolutionary chain, and perhaps this gene was responsible. The finding could help a whole lot of bald people (and people with other hair-related conditions). Imagine if you could bring back your hair just by getting rid of a protein telling your hair not to grow.
“A nucleotide polymorphism in the human DKK2 locus is associated with increased risk for androgenetic alopecia,” explained Millar. “It is possible that elevated DKK2 expression or function contributes to miniaturizing hair follicles, but whether this variant affects DKK2 expression or function, and whether it plays a functional role in this condition is not yet known. This is a fascinating area for future studies.”