We welcome you to Tiny Expeditions, where we’ll take some little journeys into the tiny science of genetics, DNA and inheritance. Season One will focus on stories of morphology—the way animals look and the reasons behind it.
Our guide for the season will be HudsonAlpha Institute for Biotechnology Faculty Chair Greg Barsh, MD, PhD, who is an expert in animal morphology.
Our first little journey traces the evolutionary line that tracks from wolves to dogs.
“Dogs arose from wolves in the relatively recent past,” Barsh notes. “Somewhere longer than probably, say, 10-thousand years ago. Somewhere shorter than, say, 30-thousand years ago”
It’s no big revelation that dogs take after wolves. But did you know somewhere down the line, some wolves started to take after dogs?
The key is in the color.
Most animals attribute color to their melanocortin 1 receptor, also known as the MC1R.
Barsh explains, “The function of the melanocortin 1 receptor is to tell melanocytes to produce a lot of dark melanin that is usually either black or brown.” If the MC1R gets blocked or deleted, you get lighter pigment—yellow, red or maybe cream.
The MC1R is probably more familiar than you realize. If you’ve ever seen someone with the classic red hair, fair skin and freckles look, it’s caused by inactivating mutations of MC1R.
However, black dogs get their color differently than most other animals, because there’s nothing wrong with their MC1R that would cause the overproduction of melanin that typically creates black fur.
Barsh and his team went to work, looking for the genetic changes that created black dogs. That’s a giant (if also tiny) task. A dog’s genome has 3 billion base pairs; the Barsh team found changes in three of them.
To find out why those three base pairs matter so much to broader health, the secrets they reveal about wolves and the beautiful thing they demonstrate about genetics—listen to Tiny Expeditions Episode 1: What Do Wolves Owe Dogs?
