While your average mouse lives for around four years, naked mole rats may survive till past their thirties. Scientists suspect such longevity, rarely seen in rodents, is linked to the naked moles’ resistance to cancer. There have been no instances of cancer occurring naturally in the species. Their secret to staying cancer-free is a super sugar called high-molecular-mass Hyaluronan (HMM-HA). When secreted, HMM-HA prevents cells from overcrowding and forming tumours.
A happy coincidence
HMM-HA may have first evolved as an adaptation for animals that have to squeeze through tight, rocky tunnels underground. It helps make their skin stretchy - grab hold of one and you’ll feel like their skin is slipping from your grasp. It may have been a happy coincidence that the HMM-HA also signals cells to stop them from becoming cancerous. Clinical use of the naked moles’ HMM-HA will open up new possibilities for cancer prevention and life extension in humans.
Fructose instead of glucose
The air the naked moles breathe is so thin it would kill humans in a heartbeat. By switching to fructose for fuel, naked moles can hold out for as long as 18 minutes in zero-oxygen conditions. Fructose, unlike glucose, does not need oxygen to create energy. The cells in the naked moles’ vital organs contain proteins that transport fructose and required enzymes. This finding may translate into a way to aid humans suffering from an oxygen-depriving heart attack or stroke.
Queen of the colony
Naked mole rats are one of the only two mammalian species to live in structured social colonies. Each colony comprises 70 to 300 naked mole rats, led by the queen. She is larger than the others and the only one to breed. The queen often inspects the tunnels and chambers that make up her ‘kingdom’, biting and pushing her ‘subjects’ to remind them who’s boss. For the queen is not born into her position: she earned it by fighting off the other females when the queen before her died. A queen’s position is never secure and she must defend her title if she wants to stay in charge.
Naked mole rats live in complex underground burrow systems, with food storage, nest chambers, and toilets! Some run just under the surface of the ground, while others can go 2m deep. A colony's total tunnel length can add up to 4km, covering an area of up to six football fields!
The naked moles are also the only cold-blooded mammals – they huddle together for warmth, or regulate their body temperature by moving between warmer and colder chambers in their underground home.
Naked moles seem to do the majority of a year's digging just after the rainy season, when the normally hard ground is softened. Those at the ‘frontline’ break through the dirt with their incisors. They shut their nostrils and their lips close behind their front teeth, so they can dig without choking on the dirt. Workers behind them use their strong hind limbs to sweep the soil to a surface opening, where the dirt is kicked up onto the ground, forming a mole hill.
One for all and all for one
A colony cooperates for the common good of the group and that includes the sharing of food. If a food scout finds a tasty tuber, he or she carves a piece off with those powerful, ever-growing incisors and hurries back to the group, chirping and waving the morsel overhead. The other workers follow the scout's scent (they all roll in their own faeces so they share the same smell) to the tuber, which is then brought back, piece by piece, to the food chamber.