Naked mole rats are fertile until they die. Here’s how you can help us.

Most mammals, including humans, have a constantly declining egg supply, and fertility declines with age.but naked mole rat Researchers may have shed light on why it’s so appealing.

Naked mole rats produce new eggs in addition to having a very large store of healthy egg cells in their ovaries. rear was born according to new research It was published in the magazine Nature CommunicationsHumans, on the other hand, can be born with all the eggs they’ve ever had.

Naked mole rats, native to East Africa, have baffled scientists for decades. These shriveled, communal rodents can live up to 37 years. extreme hypoxiaand don’t get cancerproperties that are all being studied to develop new drugs and treatments.

Now, the secret behind the lifelong fertility of naked mole rats may provide clues to help extend human fertility, say study leaders Miguel Brieno-Enriqueza reproductive researcher at the University of Pittsburgh.

“Female reproduction and female aging are understudied,” he says. “In our case, we want to [investigate] The ovaries are key to aging and protecting them is the main goal. ”

amazing number of eggs

exact age Decline in female fertility is hotly debatedHowever, according to most studies, a woman’s egg cells begin to deteriorate around age 40, and giving birth at this age may increase the risk of chromosomal abnormalities and other diseases. around 50 years old, menopausethe female ovaries completely stop releasing eggs. (Learn why many women choose to freeze their eggs.)

Female naked mole rats, however, can reproduce for life without significant loss of egg quality. To test how this is possible, Brieño-Enríquez and his colleagues oophorectomized six of his naked mole rats from a research colony at the University of Pittsburgh. These ovaries were then analyzed under a microscope at different developmental ages (from 1 to 90 days) and compared to ovaries from laboratory mice, animals commonly used as models of human reproduction. bottom.

The team uses a variety of dyeing techniques, immunofluorescence— a glowing marker that can track cell division — to count the number of cells Germ cell On the fifth day, they found a surprising number of germ cells in the naked mole rat.

“For me, it was really exciting, but part of it was also scary,” he says. Ned Place, a senior author and research reproductive biologist at Cornell University School of Veterinary Medicine. “I was like, ‘Oh my God, someone, me and my lab, are going to have to count all these cells.'”

When scientists looked again three days later, they found that the naked mole rat’s ovaries had even more germ cells than the last time they checked. This means that rodents were creating new cells to add to their ovarian reserve. Female naked mole rats had an average of 1.5 million eggs at 8 days of age. That’s about 95 times more than in a rat of the same age.

The researchers also found progenitor cells in 10-year-old naked mole rats, suggesting that the creation of new eggs may continue into their 20s and 30s. (Read that naked mole rats are resistant to burning pain.)

learn from royalty

Like bees, naked mole rats form colonies, sometimes consisting of hundreds of individuals, with only one breeding queen.

This dominant female suppresses the fertility of other females until the end of her reign. When the queen dies or is killed, other females fight for the throne and the winner becomes the colony’s new breeding female.

To test how this process affects fertility, the researchers removed a few non-breeding 3-year-old females from the colony to activate their reproductive system, thereby creating their own queens. is created.

They found that the ovaries of these females already had primordial germ cells, but it was only when they transitioned to the queen that the cells began to divide into eggs.

This means that previously unutilized cellular reserves can become viable eggs even after years of dormancy. This is a finding that may hold clues to preventing female fertility decline.

Help improve female fertility

“What they really, really beautifully showed in this paper, [naked mole rats] It’s the perfect model for humans.” Gisella Helpera neuroendocrinology investigator who was not involved in this study.

For example, scientists can study puberty in naked mole rats without having to undergo genital surgery, as they do in mice.

“What we want to know is how naked mole rats can keep their oocytes healthy and happy,” adds Brienho-Henriquez. From there, researchers could eventually develop new drug targets or supplements to protect a woman’s existing egg cells. I stress that it is unlikely.

However, he believes there is much to be learned from naked mole rats.

“I generally like weird things. Work feels like a playground when it comes to organisms that give you room to play,” he says. “It’s also painful because whatever you want to see is the exact opposite.”