Sperm Guidance in Non-mammalian Species
Sperm guidance in non-mammalian species is performed by 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).
Read more about this topic: Sperm Guidance
Famous quotes containing the words guidance and/or species:
“The rest, called literature, is a dossier of human imbecility for the guidance of future professors.”
—Tristan Tzara (1896–1963)
“Under the species of Syndicalism and Fascism there appears for the first time in Europe a type of man who does not want to give reasons or to be right, but simply shows himself resolved to impose his opinions.”
—José Ortega Y Gasset (1883–1955)