Scientists have identified a specific protein that keeps sperm swimming in a straight line. Called “VSP”, the protein is responsible for controlling the influx of calcium ions to the tail or flagellum of the sperm which helps the sperm swim towards to egg.
Sperm motility is an important factor that is required for fertilisation, but without motility, sperm can’t make its way up to the fallopian tube and to the egg. When the sperm is close to its destination, it will become turbo-charged (also known as capacitation) and will ultimately race towards the egg.
The sudden enhanced motility of the sperm is caused by an influx of calcium ions to the sperm’s tail, which is controlled by VSP. Without VSP, the sperm will lose its ability to effectively race towards the egg.
When observed closely, the researchers noticed that sperm deficient in VSP were in fact swimming around in circles during that final leg of their journey, making it harder for them to reach the egg.
This breakthrough will ultimately aid in developing future fertility treatments for patients who have troubles with sperm motility and hopefully help increase changes of fertilisation.