Staying Away from Females Leads to Longer Lifespan?

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Staying Away from Females Leads to Longer Lifespan?

Staying Away from Females Leads to Longer Lifespan? Exposure to Female Odor Increases Male Mortality and Accelerates Reproductive Aging.

The aging of reproductive capacity and late-life function leads to an increase in mortality rates with age, which is related to the investment in growth and reproduction early in life. This connection is at least partially a result of trade-offs between life-history traits, such as current growth and future reproduction, and current reproduction and lifespan.

The prevailing view is that these trade-offs occur because the allocation of limited resources is restricted, such as the allocation of limited energy. There is also a hypothesis that the presence of aging and the apparent trade-offs between early and late-life functions may be related to stronger evolutionary selection for functions that drive early-life growth and reproduction. Both hypotheses can explain why high early reproduction rates are related to faster aging.

In mammals, reproductive activity is negatively correlated with lifespan, and there is evidence that sensory cues can alter this trade-off. However, it is not clear what the long-term effects of female odor are on male lifespan or aging.

On February 28, 2024, researchers at the University of Otago in New Zealand published a study titled “Exposure to female olfactory cues hastens reproductive ageing and increases mortality when mating in male mice” in the journal “Proceedings of the Royal Society B: Biological Sciences”.

The study found that male mice exposed to the odor of female mice from middle age to old age had an increased mortality rate and accelerated reproductive aging in male mice, indicating that sensory perception of mates may be an important driving factor in mammalian life-history trade-offs.

Staying Away from Females Leads to Longer Lifespan? Exposure to Female Odor Increases Male Mortality and Accelerates Reproductive Aging.

In this study, researchers tested whether exposure to female odor would affect male mouse mortality rates and reproductive aging.

Researchers placed male mice aged 10-24 months in four environments:

Raised alone;
Raised with two female mice;
Raised alone with exposure to the odor of two absent females;
Raised with two males and exposed to the odor of two absent females.

In addition, at 24 months of age, male mice were paired with two young female mice, regardless of their previous social environment, and their fertility was assessed over 64 days.

The study found that by the end of the experiment at 26 months of age, exposure to female odor significantly affected the mortality rate of male mice. Of the 30 male mice exposed to female odor, 15 died, while only 4 of the 30 male mice not exposed to female odor died.

The results suggest that exposure to female mouse odor increases male mouse mortality rates.

Researchers also analyzed the effect of exposure to female mouse odor on the fertility of male mice. At 24 months of age, all surviving males were transferred to be raised with young female mice for 64 days to assess their fertility in old age.

The analysis found that male mice exposed to female mouse odor had fewer offspring during late-life mating, regardless of whether the males had prior mating experience, indicating that males experience reproductive aging, and long-term exposure to female odor affects male fertility.

Regarding the possible mechanisms by which exposure to female odor shortens male lifespan, the study suggests that early exposure to female odor increases male reproductive investment early in life, leading to trade-offs in reproductive rates and mortality rates.

The researchers stated that sensory cues can affect hormone release, leading to short-term physiological effects on animals and humans. This result highlights the importance of sensory perception of mates as a driving factor in mammalian life-history trade-offs.

In conclusion, the study suggests that exposure to female odor affects male mouse reproductive aging and mortality rates, further demonstrating that odor from mates can affect the aging process.