We need to talk about why the naked mole-rat is an incredible mammal
If you had told me the naked mole-rat, a hairless burrowing rodent, would be one of the key components to understanding ourselves, I’d have laughed you out of the room. Well, perhaps not – I like to think I’m an open-minded individual – but I certainly wouldn’t have thought you were speaking sense.
However, at this year’s New Scientist Live my attention was drawn to a large stand focusing entirely on the naked mole-rat. As it turns out, these burrowing rodents are a perplexing creature, behaving unlike many other mammals on the planet, and blessed with some truly unique characteristics which makes them fascinating to researchers the world over.
By better understanding the naked mole-rat, we could potentially develop cures for cancer, help those with respiratory diseases and even develop ways to prolong our lives.
1. The naked mole-rat has a complex societal structure
Image: Bob Owen – Flickr
Unlike any other mammal on the planet, the naked mole-rat has a complex eusocial structure that’s similar to that of ants and some wasps. This means that only one female naked mole-rat, otherwise known as the queen, reproduces with a handful of chosen males. The rest of the mole rat society function as sterile workers and, most interestingly of all, non-reproductive females can become reproductive females if required, with their biology changing to fit the role.
2. The naked mole-rat can live with almost no oxygen
Image: Bernard Dupont – Flickr
Because the naked mole-rat lives in underground colonies, there’s a limited supply of oxygen available to them. But that’s absolutely fine as its small lungs and high efficiency of oxygen uptake in the blood means it can get by with as little as 5% oxygen in the air. It could easily survive in an atmosphere of 80% CO2, 20% oxygen and even within a zero-oxygen environment, it can survive for nearly 20 minutes without distress. Humans struggle to make it past six.
It can do this because it starts to generate fructose to keep its body going instead of drawing upon oxygen. During this period it’ll lose consciousness, with its heart rate dropping, but if restored to an oxygen environment in time, it can survive without lasting damage.
3. The naked mole-rat is practically immune to cancer
One incredible trait of the naked mole-rat is its resistance to cancer. While there is a chance it can get some cancer-related disorders, the naked mole-rat has a high resistance to tumors on a genetic level. Not only does it benefit from the p27 gene found in most mammals to stop cell reproduction once it reaches a certain density, but it also has the p16 gene too. P16 functions in a similar way to that of p27, but it stops cell reproduction at a much lower density meaning that, with this gene combination, the naked mole-rat has a double-barrier to uncontrolled cell growth – a key sign of cancer growth.
4. The naked mole-rat can’t feel pain
All mammals’ skin transmits pain signals to the central nervous system except for, you guessed it, the naked mole-rat. As it lacks a neurotransmitter known as substance P, this means that it actually feels no pain at all. Interestingly, when given substance P the naked mole-rat does begin to feel pain, however, it still retains an immunity to acid burn.
It’s unclear if this resistance to pain is limited to just physical ills or if they really are just soulless beings. Surely everyone has to at least feel a bit down now and again.
It’s also thought that this lack of substance P is responsible for why the naked mole-rat doesn’t scratch or have itches like other rodents.
5. The naked mole-rat is the longest-living rodent in the world
If the naked mole-rat wasn’t phenomenal enough already, it turns out it’s also the longest-living rodent around, reaching the lofty age of 32.
Their ability to live to such an old age is partly due to their resistance to cancers, along with their ability to regulate and maintain their vascular activity. Many see naked mole-rats as living in “pulses” as they slow their metabolism during harsher times and thus, in the process, slow the speed of aging.
Another interesting reason for why naked mole-rats survive longer than your garden-variety rodent is because they share DNA common ground with us. Both humans and naked mole-rats have DNA repair genes present in their DNA pathways. Not only was this discovery key in understanding why naked mole-rats can live longer, but it also proved our theories around aging is the result of damaged DNA.
Main image: Tim Evanson – Flickr