Sperm Chemotaxis - Sperm Chemotaxis in Non-mammalian Species

Sperm Chemotaxis in Non-mammalian Species

In sperm chemotaxis, the oocyte secretes a chemoattractant, which, as it diffuses away, forms a concentration gradient: a high concentration close to the egg, and a gradually lower concentration as the distance from the oocyte is longer. Spermatozoa can sense this chemoattractant and orient their swimming direction up the concentration gradient towards the oocyte. Sperm chemotaxis was demonstrated in a large number of non-mammalian species, from marine invertebrates (Cosson, 1990; Miller, 1985) to frogs (Al-Anzi and Chandler, 1998).