Whether it is a signature dance move, a particular outfit, or inflating and bouncing an air-sac to make an odd noise, we all have a way to make a prospective partner notice us. In the animal kingdom, mating strategies range from the fairly mundane to decidedly weird. In February’s Osteology in Action, we are going to take a closer look at a dating accessory we are all familiar with: deer antlers.
When comparing antlers to the love darts that the garden snail (C. aspersum) stabs into the head of their mates, they seem a bit tame. Sure they grow bony protrusions from their heads every year, but how is that any different from trying a new up-do to get the cute new hire to notice you?
While it’s true that there are odder animal mating techniques, there is something more to deer antlers than meets the eye. Deer antlers grow faster than any other mammalian tissue. If I were to break a bone, I would need a minimum of 6 to 8 weeks to heal a small piece of an already existing bone. In half that time, a deer can grow an entirely new set of antlers. That is up to one half meter (1.5 feet) in a single month. In order to achieve that, a deer needs to grow 2.5 cm (0.25 in) of new bone each day. For comparison, that is more than six times faster than your fingernails grow. How on earth does that happen?
The answer is bone cancer.
A group of scientists from China did genome research on 44 species of ruminants attempting to find the evolutionary source for antlers and horns. They looked at giraffes, cows, sheep, pronghorn and deer. They found what they hoped to, which was a shared ancestor, and they discovered a little something extra.
Of the genes responsible for the growth of antlers, eight are associated with bone cancer. This makes quite a lot of sense if you think about it. A tumor is essentially an abnormal growth caused by uncontrolled cell replication. Antlers grow at the same rapid, unpredictable rate as cancer cells. But if antlers are essentially tumors, why are they not harmful?
The other genes responsible for antler growth are cancer inhibitors. This means that the cancer genes, responsible for the meteoric development of antlers, are kept on a tight leash by the inhibiting genes. Thus, preventing the cancer cells from getting out of control and spreading and causing harm.
But surely, despite this natural cancer fighting system, deer still get cancer, right? They do. However, a look at zoo records find that deer have a cancer rate more than 5 times lower than other mammalian species. This is awesome news for deer (although old news for them, I am sure) and a neat fact to share with friends, but what applications does this have in the medical world?
While nothing is set in stone, (this study was just published in June of 2019) the discovery of these cells suggest that they could eventually be used to understand and develop methods of slowing and perhaps stopping cancer growth in humans and other animals.