Why the naked mole-rat is head and shoulders above us


Without a doubt, many fascinating creatures are living on our planet. One of the most extraordinary animals I ever learned about is the naked mole-rat (Heterocephalus glaber). The naked mole is a rodent, which lives in subterranean burrows in the east African countries Somalia and Ethiopia, as well as in parts of Kenia. The naked mole is obviously naked, has a poor eye-sight and the size of a small rat (not New York City rat-size!).

On top of its bizarre appearance, its eusocial organisation is unique among mammals; like bees and ants, the naked mole community consists of a queen, responsible for producing offspring, nurses, who raise the babies, and workers, who maintain the burrow. The tasks are distributed according to the age: Teenagers take care for their siblings, adults are working in the tunnels, and the strong and older naked mole colleagues become door keepers, who protect the community from invaders, like snakes. Only three males of the community and the queen are fertile. It is speculated, that a certain stress level, maintained by the queen, suppresses the growth of the ovaries of the other females. If the queen dies, other females can “relax” and become fertile. The one, which becomes pregnant first, will be the new queen.

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Even though the blind mole does not fit well in our concept of beauty, it is one step ahead of us: It features the Holy Grail of longevity! The naked mole can become 30 years old, which is ten times older than a mouse and around six times older than a rat. Researchers love the naked mole because they hope to decipher the principle of longevity by analyzing their lifestyle and metabolism. The secret is: The naked mole does not waste energy and resigns the luxury of a constant body temperature, it simply takes over the environmental temperature, which can vary between 12 °C und 32 °C. Further, the naked mole can adapt its metabolism rate according to the oxygen levels in the subterranean burrow, which can drop below 3% (air at sea level has 21 %!), if around 300 oxygen-consuming naked moles live in the badly ventilated tunnel system. The only reason the naked moles do not suffocate, is the increased oxygen binding capacity of their blood.

Longevity is not necessarily a reason to be jealous, because it comes with the cost of accumulating DNA-mutations, which can cause cancer. But not in the naked mole! On top of their long life, these guys are pretty resistant to cancer. They have highly active genes (p53 and Rb) that prevent cells from doing awkward things, like overcrowding and forming tumors. Additionally, they have a sugar called high-molecular-mass hyaluronic acid, which prevents cells from getting in contact. And here is the cherry on top (of the naked mole): they cannot feel pain. Naked moles are lacking Substance P, which is a mediator of pain.

In conclusion, naked moles are highly organized rodents ruled by a bitchy queen. Beside this drop of bitterness, they lead a long and happy life without the burden of pain and cancer. Who would not like that?

XOXO, your Nerd

You can meet Steve the blind mole here:

 

 

 


Author: I.

PhD in Biology, specialised in epigenetics