ost kindly described as
‘saggy sausages with legs and
teeth’, naked mole rats are one
of the strangest looking animals
on Earth. But their appearance
belies a remarkable set of traits. Over
the past few decades, scientists have discovered that this
hairless rodent is immune to cancer, resistant to pain,
capable of surviving without oxygen, and able to live for a
remarkably long time.
Whereas most similarly sized rodents last only a few
years (rats reach four years maximum), naked mole rats
can survive into their thirties, five times longer than
expected for their body size. The current record is held
by ‘Old Man’, who was 32 when he finally passed away
in 2010. Old Man wasn’t even unusual, as most naked
mole rats easily make it into their late twenties.
Unsurprisingly, this peculiar longevity has been
capturing the attention of scientists around the world.
What is this rodent’s secret to long life, and might we
even be able to harness it for ourselves? Let’s go
underground...MEET THE MOLE RATS
Naked mole rats are actually neither moles nor rats, but a
rodent more closely related to porcupines and guinea pigs.
They live in large colonies beneath the East African desert,
constantly tunnelling in search of the elusive but tasty plant
roots that make up their diet.
Strangely for rodents, only a few animals in the colony
are sexually active: a sole dominant queen who rules the
roost, and a handful of lucky stud males. The rest stay as
non-breeding workers responsible for digging,
maintaining and guarding their twisting network of
tunnels. This unusual lifestyle first caught the attention of
researchers as far back as the 1970s, who brought wild
naked mole rats from Africa to establish colonies in labs
and zoos around the world.
One such colony can now be found at Queen Mary
University of London. Here, I visit mole rat expert Dr Chris
Faulkes, who takes me into a stifling room full of
interconnected transparent plastic pipes teeming with
nearly 300 busy, pink bodies. The warm air buzzes with
the constant sound of scratching – their teeth are
continually growing, so they have to keep gnawing at the
tunnel walls – interrupted with high-pitched squeaks and
occasional scuffles.
Faulkes reaches into a nest box to retrieve a heavily
pregnant queen. Looking at the wriggling rodent in his
hands, I can’t help thinking that it already looks like acaricature of a centenarian with its sagging, hairless
skin. “They live in the dark – their looks don’t matter!” he
laughs. Even the babies share this ancient appearance,
although apparently the oldest animals do have more
papery, pale skin and a ‘jowly’ look about them. Naked
mole rats also stay fit and healthy far longer than most
other mammals, maintaining their youthful good looks
and vigour for at least two-thirds of their lifespan.
As Faulkes explains, the key to the naked mole rat’s
longevity lies in understanding their lifestyle and underlying
biology. “Most people would agree that it’s a whole
combination of factors that all come into play,” he says.
“Naked mole rats have a low body temperature and a low
metabolic rate, they’re in a calorie-restricted environment,
and they have a whole raft of biochemical and genetic
differences that we’re only just starting to unravel.”UNDER THE SKIN
Shielded from the scorching sunshine in their native
Ethiopian landscape (or warmed by a heater in the
laboratory), the mole rats’ burrows stay at a constantABOVE: Their teeth can
tackle a diet of roots
and tubers, but also
help the mole rats dig
through soil
RIGHT: Dr Chris Faulkes
with one of his naked
mole ratsLORNA FAULKES ILLUSTRATIONS: LINDSAY LEIGHSCIENCE