” Naked mole-rats are the weirdest mammals,” stated lead author Miguel Brieño-Enríquez, M.D., Ph.D., assistant professor at Magee-Womens Research Institute and the University of Pittsburgh School of Medicines Department of Obstetrics, Gynecology and Reproductive Sciences. Naked mole-rats live in colonies of several lots to hundreds of individuals. Just the single dominant woman in a nest can reproduce, and she suppresses recreation in other women to maintain her queenly status.
” Unlike ants or bees, a female naked mole-rat is not born a queen,” explained Brieño-Enríquez. We hope to utilize what we are finding out from the naked mole-rat to secure ovary function later in life and lengthen fertility.”
Miguel Brieño-Enríquez, M.D., Ph.D., assistant professor at Magee-Womens Research Institute and the University of Pittsburgh School of Medicines Department of Obstetrics, Gynecology and Reproductive Sciences. Credit: Miguel Brieño-Enríquez
For most mammals, including human beings and mice, women are born with a finite variety of egg cells, which are produced in utero by means of a procedure called oogenesis. Due to the fact that this minimal supply of egg cells diminishes gradually– some are released throughout ovulation, but the majority of just die– fertility declines with age.
On the other hand, naked mole-rat queens can breed right through aging, recommending the rodents have special procedures to protect their ovarian reserve and prevent waning fertility.
” There are three possibilities for how they do this: They are born with a lot of egg cells, not as much of these cells die, or they continue to develop more egg cells after birth,” stated Brieño-Enríquez. “My favorite hypothesis is that they utilize a mixed drink of all three.”
Sure enough, Brieño-Enríquez and his collaborators discovered proof for each of the three procedures.
The researchers compared ovaries from naked mole-rats and mice throughout different phases of advancement. In spite of their comparable sizes, mice live four years at many and start to show a drop in fertility by 9 months, whereas naked mole-rats have a life expectancy of 30 years or more.
They found that naked mole-rat females have extremely big numbers of egg cells compared to mice and that death rates of these cells were lower than in mice. For instance, at 8 days old, a naked mole-rat female has on typical 1.5 million egg cells, about 95 times more than mice of the very same age.
Many extremely, the research study discovered that oogenesis occurs postnatally in naked mole-rats. Egg precursor cells were actively dividing in 3-month-old animals, and these precursors were found in 10-year-old animals, suggesting that oogenesis might continue throughout their lives.
Ned Place, Ph.D., M.D., professor at the Cornell University College of Veterinary Medicine. Credit: Cornell University
” This finding is amazing,” said senior author Ned Place, Ph.D., M.D., teacher at the Cornell University College of Veterinary Medicine. “It challenges the dogma that was established almost 70 years earlier, which stated female mammals are endowed with a finite number of eggs prior to or shortly after birth, without any additions being made to the ovarian reserve afterwards.”
Naked mole-rats reside in colonies of numerous dozen to hundreds of people. Like bees or ants, nest members divvy up jobs, consisting of offering defense, digging tunnels, looking after young and collecting food. Only the single dominant female in a colony can reproduce, and she suppresses recreation in other women to preserve her queenly status.
” Unlike ants or bees, a female naked mole-rat is not born a queen,” described Brieño-Enríquez. “When the queen passes away or is gotten rid of from the colony, secondary women contend to take her location and become reproductively activated. Any girl can end up being a queen.”
To learn more about this procedure, the researchers eliminated 3-year-old females from the colony to prompt reproductive activation and compared these new queens with subordinate females. They found that non-breeding subordinates had egg precursor cells in their ovaries, but the cells started dividing just after a transition to queen.
” This is essential since if we can determine how theyre able to do this, we may be able to develop new drug targets or strategies to help human health,” stated Brieño-Enríquez. “Even though human beings are living longer, menopause still happens at the very same age. We want to use what we are gaining from the naked mole-rat to safeguard ovary function later in life and lengthen fertility.”
” But the ovary is more than simply a baby factory,” he continued. “Ovary health affects cancer danger, heart health, and even lifespan. Better understanding of the ovary might help us find methods to enhance general health.”
Recommendation: “Postnatal oogenesis causes an exceptionally large ovarian reserve in naked mole-rats” 21 February 2023, Nature Communications.DOI: 10.1038/ s41467-023-36284-8.
Other authors who contributed to the research study were Mariela Faykoo-Martinez, Michael D. Wilson, Ph.D., and Melissa M. Holmes, Ph.D., all of the University of Toronto; Meagan Goben, Patrick T. Walsh and Samia H. Lopa, Ph.D., all of Pitt; Diana J. Laird, Ph.D., of the University of California San Francisco; and Jennifer K. Grenier, Ph.D., Ashley McGrath, Alexandra M. Prado, D.V.M., Jacob Sinopoli, Kate Wagner and Paula E. Cohen, Ph.D., all of Cornell University.
This research study was funded by the National Institutes of Health (R00HD090289, P50HD096723 and P50HD076210), the Natural Sciences and Engineering Research Council of Canada (RGPIN2011-402633, RGPIN 2018-04780 and RGPAS 2018-522465), the Ontario Early Researcher Award, the W.M. Keck Foundation Award, the Empire State Stem Cell Fund (C30293GG) and the Magee-Auxiliary Woman Scholar endowment.
A naked mole-rat (Heterocephalus glaber) woman. Naked mole-rats can replicate throughout their extremely long lifespans, unlike people and other mammals Credit: UPMC
New research recommends that naked mole-rats produce eggs throughout their lives, challenging the dogma that female mammals have a finite ovarian reserve.
Unlike human beings and other mammals, which end up being less fertile with age, naked mole-rats can replicate throughout their incredibly long life-spans. A brand-new study, released today (February 21, 2023) in the journal Nature Communications, clarifies special procedures that bestow the rodents with what appears like eternal fertility, findings that could eventually point to brand-new treatments for people.
” Naked mole-rats are the weirdest mammals,” said lead author Miguel Brieño-Enríquez, M.D., Ph.D., assistant teacher at Magee-Womens Research Institute and the University of Pittsburgh School of Medicines Department of Obstetrics, Gynecology and Reproductive Sciences. “Theyre the longest-lived rodent, they almost never get cancer, they dont feel pain like other mammals, they live in underground colonies, and just the queen can have infants.