As people are waiting longer and longer to have children, the average age of new parents has been rising for the last 50 years. However, childbearing years are limited for women.
Scientists say that as women age, their stem cells are less effective at renewing tissue. They say this is especially true of germline stem cells that produce eggs and sperm.
Recently, UCSB biologists published a study on the fruit flies’ ability to extend the longevity of their stem cells.
“When fruit flies emerge in their adult form into cold, dark conditions, they enter a dormancy called diapause. It’s a seasonal response to save energy for reproduction when success is more likely: in warmer times of the year. Diapause can double a fly’s lifespan and significantly extend their reproductive period,” reported Harrison Tasoff, a UCSB science writer.
So what does this research in fruit flies have to do with humans?
“We already know we can learn things about longevity and aging from animals with shorter lifespans,” Dr. Denise Montell, who teaches molecular, cellular, and developmental biology at UCSB, told the News-Press.
“We are operating on the premise that studying simple animals yields insights into human biology,” she said.
UCSB has a five-year grant with the National Institute on Aging to study the process of diapause.
The study has three parts.
The first part is to “do a first ever analysis of stem cells and how they are pausing and reanimating,” said Dr. Montell. “The second part is to look at genes in flies, and what genes promote diapause and enable the animals to reanimate after dormancy. The final part is to study behavioral changes in animals, understand how behavioral changes are coming about, what is regulating them and whether or not we can manipulate them.”
The benefits of diapause is not only in improving the length of reproductive years, but it improves the health span as well.
“It is definitely not a finely tuned program where when they reanimate. They are not as fertile as the young flies, pausing biology is not 100% efficient,” said Dr. Montell when asked about the drawbacks.
However, they are still producing more than a fly at the same point in their life span that hasn’t been through diapause.
“The benefit is preserving fertility for a longer period of time than otherwise and extending the health span and fertility for longer,” said Dr. Montell.
While the research is years away from proving this, what the researchers hope to show is that by pausing the growth of stem cells just as scientists do in fruit flies, scientists can prolong the childbearing years for women, pushing off menopause until later in life. This longevity of reproductive years could be proven true for men as well, although researchers’ higher priority concerns women.
Additionally the scientists hope to prove that pausing the growth of stem cells can extend the healthspan and potentially the lifespan of humans. If this is proven, a 60-year-old could look and act much more like a 40- or 50-year-old, according to UCSB research.