Protein defect leaves sperm chasing their tails

Researchers have characterized a protein, called VSP, that keeps sperm swimming in straight lines. Deletion of the protein caused sperm to swim in circles, significantly reducing fertilization rates. VSP also controlled the influx of calcium ions into the flagellum, which is necessary for propulsion of the sperm towards the egg. The researchers hope that their discovery will aid in the development of fertility treatments to enhance sperm motility.