Science: Sperm, Homosexuality and Primordial Soup

Lauren Admire | 8 Feb 2010 21:00

The Slow Sperm Wins the Race

The well-known race of sperm to egg assumes that the fastest sperm wins the embryo. Well, yes and no. If a sperm starts swimming too fast, it tires out and dies, much like the hare from Aesop's Tales, and pauses halfway through sprint to rest in the fallopian tubes. The pH level of the sperm affects its speed and timing: The less acidic it is, the faster it swims. However, something must trigger it into breaking away from the fallopian tube and continuing the final sprint towards the egg.

"It's a tough job for a sperm - when it's deposited it has to travel a long distance to the egg sites," explains Deijan Ren. "This process has been known for many decades, but how it actually happens remained a mystery."

However, researchers have found the mechanism that raises the sperm's pH and gives it the final push towards the finish line. In order to increase its pH, the sperm jettisons protons. "The concentration of protons inside the sperm cell is 1,000 times higher than outside. If you just open a pore, protons will go outside- we identify the molecule that lets them out," states Dr. Yuriy Kirichok, lead researcher.

As the sperm travels closer to the egg, a substance in the female reproductive tract causes the sperm to open its pores and release protons, prompting it to release itself from the fallopian tube and make the final dash towards the egg.

Source: Discover


Lauren Admire wonders how the primordial soup tasted.

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