Evolutionary Phenonmenon in Mice May Explain Human Infertility

Scientists at the University of Liverpool have found that field mice have evolved a unique way of ensuring faster fertilization, 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 fertilization 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.

Release date: January 23, 2008
Source: University of Liverpool