Study Shows Females Can Delay the Aging of Sperm Cells for Decades

By Dan Nosowitz

Sperm Cells Wikimedia Commons

A new study led by Dr Klaus Reinhardt at the University of Sheffield shows that females of some species can prolong the lifespan of ordinarily short-lived sperm cells by days, months, or even decades, waiting for the optimal time to use it. The study could also have some significant implications for the general study of ageing.

Here's the deal: sperm cells are very short-lived, typically. They have a very high metabolic rate compared to other cells, but the reasons why sperm cells deteriorate so quickly are still not well-understood. It was assumed that part of the problem is that sperm cells produce a comparatively high amount of free radicals, damaging the cells.

The study used fluorescence-lifetime measurement, more often used in oncology, to examine the sperm cells held in the body of female crickets. They compared the metabolic rate and production of free radicals in the female crickets to sperm stored elsewhere. They found that the females could somehow alter both of those attributes--the metabolic rate within the females was a whopping 37 per cent lower than the other sperm.

That process allows many species of females to store sperm cells for a very long time. It's not just insects; birds, fish, and reptiles are also shown to have the same ability to delay ageing in sperm cells. The most impressive creature is an insect, though--queen ants can keep these cells alive for an insane 30 years.

Some exciting implications are coming from this research. It aligns with the theory that free radicals are a vital element in the ageing of cells, but it also explains why fertility tests on sperm are so unreliable. Without a female to slow their death rate, sperm cells could quickly perish during the test.