Naked mole rats could hold the key to eternal fertility in women, scientists have theorized. For most mammals, including humans, females are born with a finite number of eggs and become gradually less fertile as they get older. In contrast, naked mole rats are known for their ability to continue producing offspring well into old age.
It was unclear whether the subterranean rodents were born with an exceptional number of eggs or whether they have a unique ability to create new eggs as they age.
But a study by scientists at Cornell University and the University of Pittsburgh has shown that they do both — and the team hopes that studying the rats’ genetic quirks will help develop treatments that can reverse the menopause in women.
Dr Miguel Brieno-Enríquez, a gynecologist at the University of Pittsburgh and lead author of the study, said: ‘This [find] is important because if we can figure out how they’re able to do this, we might be able to develop new drug targets or techniques to help human health.
‘Even though humans are living longer, menopause still happens at the same age.
Naked mole rats are able to produce new eggs outside the womb, a study has found
‘We hope to use what we are learning from the naked mole rat to protect ovary function later in life and prolong fertility.’
For the paper, scientists compared ovaries from naked mole rats with those of mice.
At eight days old, a female naked mole-rat has 1.5 million egg cells on average – nearly 95 times more than mice of the same age.
Unlike mice, the study also found naked mole rats were able to produce new eggs after birth, with egg-bearing cells still dividing into new cells at 10 years old.
The experts said this suggested egg production probably continues throughout their 30-year lives.
Dr Ned Place, a population medicine expert at Cornell University in New York and senior study author, said: ‘This finding is extraordinary.
‘It challenges the dogma that was established nearly 70 years ago, which stated female mammals are endowed with a finite number of eggs before or shortly after birth, without any additions being made to the ovarian reserve thereafter.’
Dr Brieno-Enriquez added: ‘The ovary is more than just a baby factory. Ovary health influences cancer risk, heart health and even lifespan.
‘Better understanding of the ovary could help us find ways to improve overall health.’
Like bees or ants, naked mole rats live in colonies and divvy up tasks, including providing defense, digging tunnels, caring for young and collecting food.
There is only one single dominant female — or queen — who produces eggs.
The challenging lifestyle has made them one of the most communicative creatures in the world.
Over millions of years of evolution, they have cast off things which use their energy — such as fur.
They use their distinctive, elastic ‘baggy’ skin to squeeze through tunnels.
The unsightly creature has fascinated medical experts for decades. It is cancer resistant – and has the lowest metabolic rate of any mammal.
Evolution has shut down everything that is not absolutely necessary – including extra nerve receptors so it can’t feel pain.
Dr Brieno-Enriquez added: ‘Naked mole-rats are the weirdest mammals.
‘They’re the longest-lived rodent, they almost never get cancer, they don’t feel pain like other mammals, they live in underground colonies — and only the queen can have babies.
‘But to me, the most amazing thing is they never stop having babies — they don’t have a drop in fertility as they age. We want to understand how they do this.’
What is the menopause?
Menopause is when a woman stops having periods and is no longer able to get pregnant naturally.
It usually happens between the ages of 45 and 55.
It is a normal part of aging and is caused by levels of the sex hormone estrogen dropping.
Some women go through this time with few, if any, symptoms.
Others suffer from hot flushes, sleeping difficulties, mood swings and brain fog, which can last for months or years and might change over time.
HRT replaces the hormones and is the main treatment used to treat symptoms — which can be severe and disrupt day-to-day life.
Menopause happens when your ovaries stop producing as much of the hormone estrogen and no longer release an egg each month.