Skip to main content Accessibility help

We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.

Close cookie message
×
  1. Home
  2. Search

Refine search

Refine search

Access:
Content type:
Publication date:
Apply   From and To filters
Subject: Show more
Journals Show more
Publishers: Show more
Societies Show more
Series: Show more
Collections: Show more

Actions for selected content:

Select all | Deselect all
  • View selected items
  • Export citations
  • Download PDF (zip)
  • Save to Kindle
  • Save to Dropbox
  • Save to Google Drive

Save Search

You can save your searches here and later view and run them again in "My saved searches".

Please provide a title, maximum of 40 characters.
Cancel
×

2 results

  • 6 - Regulation of capacitation

    • By Bart M. Gadella, Departments of Biochemistry and Cell Biology, Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan, Utrecht, The Netherlands, Pablo E. Visconti, Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA
  • Edited by Christopher J. De Jonge, University of Minnesota, Christopher Barratt, University of Birmingham
  • Book:
    The Sperm Cell
    Published online:
    14 August 2009
    Print publication:
    06 April 2006, pp 134-169

  • Summary

    Introduction

    Mammalian sperm are not able to fertilize eggs immediately after ejaculation. They acquire fertilization capacity after residing in the female tract for a finite period of time that varies depending on the species. In 1951, Chang (1951) and Austin (1951) independently demonstrated that such a period of time in the female tract is required for the sperm to acquire their fertilizing capacity. Both authors observed that freshly obtained rabbit sperm introduced into the Fallopian tubes shortly after ovulation were not able to penetrate the eggs; instead if sperm were introduced a few hours before ovulation, the majority of the eggs were later observed to be fertilized. This observation led them to conclude that freshly ejaculated sperm are incapable of penetrating the zona pellucida immediately, and that sperm must remain within the female tract for a period before they are able to penetrate the eggs. Following these original observations, many studies confirmed that the environment of the female tract induces a series of physiological changes in the sperm; these changes are collectively called ‘capacitation’. Inherent to these first observations was that capacitation state became defined using fertilization as end-point.

  • Presence of cumulus cells during in vitro fertilization protects the bovine oocyte against oxidative stress and improves first cleavage but does not affect further development

  • A. Nader Fatehi, Bernard A.J. Roelen, Ben Colenbrander, Eric J. Schoevers, Bart M. Gadella, Mart M. Bevers, Rob van den Hurk
  • Journal:
    Zygote / Volume 13 / Issue 2 / May 2005
    Published online by Cambridge University Press:
    20 July 2005, pp. 177-185

  • The present study was conducted to evaluate the function of cumulus cells during bovine IVF. Oocytes within cumulus–oocyte complexes (COCs) or denuded oocytes (DOs) were inseminated in control medium, or DOs were inseminated in cumulus cell conditioned medium (CCCM). DOs exhibited reduced cleavage and blastocyst formation rates when compared with intact COCs. The reduced blastocyst formation rate of DOs resulted from reduced first cleavage but subsequent embryo development was not changed. Live-dead staining and staining for apoptotic cells revealed no differences in blastocysts from oocytes fertilized as COC or DO. Fertilization of DOs in CCCM partially restored the cleavage rate, suggesting that factors secreted by cumulus cells are important for fertilization but that physical contact between oocytes and cumulus cells is required for optimal fertilization and first cleavage. Exposure of COCs to hydrogen peroxide shortly before fertilization reduced the cleavage rate, but did not lead to enhanced death of cumulus cells or oocyte death. Exposure of DOs to hydrogen peroxide, however, resulted in oocyte death and a complete block of first cleavage, suggesting that cumulus cells protect the oocyte against oxidative stress during fertilization.