Researchers have discovered that the lifespan of vertebrates is influenced by germ cells, which develop into eggs and sperm. Female germ cells increase lifespan, while male germ cells decrease lifespan. Estrogen and growth factor hormones control these effects in females, while vitamin D controls them in males. Supplementing with vitamin D can extend lifespan in both males and females. These findings help to explain the connection between reproduction and aging and suggest that vitamin D could potentially improve longevity in vertebrates.
Biologists have theorized that the difference in life expectancy between males and females could be related to reproduction, but how? In a study published in Science Advances, researchers from Osaka University discovered that germ cells, which develop into eggs in females and sperm in males, are the driving force behind sex-dependent lifespan differences in vertebrate animals. The researchers studied aging in the turquoise killifish, a small, fast-growing freshwater fish with a lifespan of only a few months. Similar to humans, female killifish live longer than males. However, the researchers found that when the germ cells in the male fish were removed, their lifespan increased, suggesting that these cells play a key role in determining the difference in lifespan between male and female vertebrate animals.Researchers discovered that when they removed the germ cells from the fish, they observed that both males and females had similar lifespans.
Lead author Kota Abe explained, “Removing the germ cells resulted in longer lifespans for male killifish and shorter lifespans for females. We were curious about the reasons behind the different effects on males and females, so our next step was to investigate the contributing factors.”
The team identified significant differences in hormonal signaling between males and females. Female killifish without germ cells had a notable decrease in estrogen signaling, which can lead to a shorter lifespan by increasing the risk of cardiovascular disease.The female killifish experienced greater growth factor signaling (insulin-like growth factor 1), leading to larger size and decreased signals that are important for health and aging. Conversely, male killifish without germ cells showed enhanced muscle, skin, and bone health. They also had increased levels of a substance that activates vitamin D, along with signs of vitamin D signaling in their muscles and skin. Vitamin D functions as a hormone, known for its role in maintaining bone strength and overall health, but it also appears to have broader positive effects on the body.The team’s findings indicated that vitamin D may have the potential to enhance lifespan, prompting them to investigate whether a vitamin D supplement could increase the fish’s life expectancy.
“Upon administering active vitamin D, we observed a significant extension in the lifespans of both male and female fish, indicating that vitamin D signaling offers health benefits throughout the body,” explains senior author Tohru Ishitani. “Our research suggests that vitamin D signaling could impact the longevity of other vertebrates, including humans.”
The revelation that germ cells impact male and female longevity in opposing ways is a crucial piece of information inDeciphering the intricate connections between reproduction, getting older, and longevity is a complex task. The role of vitamin D in this equation remains uncertain, but it may play a role in potential approaches to prolonging a healthy lifespan.
