Interactions of Sperm with the Female Reproductive Tract (Microswimmers lecture series)

Date

Jun 12, 2019

Time

4:30 PM - 5:30 PM

Speaker

Susan Suarez

Affiliation

Cornell University

Series

TUD Vorlesungsserie - Microswimmers

Language

en

Main Topic

Biologie

Other Topics

Biologie, Physik, Mathematik, Chemie

Host

Juliane Simmchen, Veronika Magdanz, Benjamin Friedrich

Description

The female reproductive tract interacts with sperm (1) to facilitate sperm migration to the egg while impeding migration of pathogens into the tract, (2) to keep sperm alive during the time between mating and ovulation, (3) to prepare sperm for fertilization, and (4) to select the fittest sperm for fertilization. In humans and cattle, natural coitus places semen in the vagina at the entrance to the cervix. Sperm must then migrate into and through the cervix, uterus, and lower oviduct to reach eggs in the upper oviduct. In the cervix, microgrooves in the walls of the cervical canal, together with the pro-vaginal flow of viscoelastic secretions, can facilitate passage of sperm through the cervix to the uterus. The viscoelasticity of the fluid can induce dynamic collective swimming of sperm, which may enhance sperm migration. In the oviduct, sperm are stored and undergo capacitation (the physiological process that prepares sperm to fertilize eggs). Sperm are stored in the oviduct by binding to its wall via specific interactions between sperm proteins and oviductal receptors. Subsequently, sperm in the reservoir capacitate and release from storage, and then migrate to the eggs. Release of sperm has been associated with modifications of the protein coating of sperm and hyperactivation of sperm movement. As released sperm swim freely, pro-uterine fluid flow can orient them to swim toward the upper oviduct, but there is also evidence that intermittent contractions can rapidly push groups of sperm up the oviduct. Finally, hyperactivation of sperm swimming can enhance migration through oviductal mucus and the viscoelastic matrices of the cumulus oophorus and zona pellucida that surround the egg. Altogether, such interactions of sperm with the female tract act to promote the success of fertilization.

Links

• Microswimmer's lecture series

Last modified: Mar 28, 2019, 1:38:25 PM