Evolutionary phenomenon in mice may explain human infertility

January 23, 2008

Scientists at the University of Liverpool have found that field mice have evolved a unique way of ensuring faster fertilisation, a phenomenon which could explain some cases of infertility in humans.

The team, in collaboration with Charles University, Prague, found that field mice sacrifice some of their immunity protection in favour of a more rapid fertilisation process. This occurs due to the absence of a protein, called CD46. Present in both animals and humans, it helps protect the body’s cells from attack by its immune system. Over time, field mice have lost the ability to produce this protein, resulting in instability of a cap-like structure, called the acrosome, present over the head of the sperm.

This instability allows the acrosome to be shed from the sperm head to create a new surface essential for sperm to be capable of fusing with an egg. This is a natural process that can take days to occur in humans, but field mice have developed a way in which this can occur rapidly.

Immunologist, Professor Peter Johnson, explains: “Field mice have traded the production of an immunologically important protein in favour of this faster fertilization process in order to compete with other mice more successfully. Female mice produce multiple eggs and if there are a lot of male mice competing for her, then it is an advantage to an individual mouse for its sperm to react quickly in order to beat other male competitors to fertilisation.”

“By improving our understanding of defects in CD46 we may improve treatments for infertility in men. Humans normally produce a single egg each month and there is no evolutionary necessity to develop rapid sperm reaction to egg fertilisation. The process is therefore much slower and so any defect in CD46 could result in sperm being destabilised too early.

“Interestingly the rapid reaction caused in mice is similar to that in IVF treatment in humans where the acronome is artificially expelled from the sperm head before it is introduced to the egg to speed up the fertilisation process. Field mice appear to do this naturally.”

Source: University of Liverpool

Explore further: Why are we still waiting for the male pill?

Related Stories

Why are we still waiting for the male pill?

July 12, 2016

Had there been a male contraceptive pill in 1976, I probably wouldn't be here to write this. That was the year when, after my mum – may she rest in peace – had been on the pill for 12 years, health worries made her doctor ...

Optogenetics makes sterile mice fertile again

January 20, 2015

Scientists from the Center of Advanced European Studies and Research (caesar) in Bonn, an Institute of the Max Planck Society, have succeeded for the first time in controlling the function of sperm by optogenetics. They inserted ...

Females fight back in sperm wars

October 17, 2013

(Phys.org) —Females exposed to a risk of sperm competition have been found to produce more defensive ova compared to the eggs of females reared under no risk of sperm competition, according to researchers at The University ...

Recommended for you

Electrons at the speed limit

August 26, 2016

Electronic components have become faster and faster over the years, thus making powerful computers and other technologies possible. Researchers at ETH Zurich have now investigated how fast electrons can ultimately be controlled ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.