Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

The main aim of the present study was to determine whether differences in the amounts of free cysteine residues in sperm nucleoproteins, which are a direct marker of the integrity of the disulfide bonds between nucleoproteins, existed between good (GFE) and poor boar freezability ejaculates (PFE) during the different steps of the freeze-thawing process. The analyzed steps were: (1) immediately before starting cryopreservation (17 °C), (2) at the end of the cooling step (5 °C), and (3) 30, and (4) 240 minutes after thawing. In addition, the present study also sought to determine whether GFE and PFE differed in the amounts of peroxides and superoxides generated during freeze-thawing as an overall measure of the boar sperm reactive oxygen species (ROS) accumulation rate. According to our results, PFE present lower resistance than GFE to cryopreservation-induced alterations of disulfide bonds between nucleoproteins, because levels of cysteine free residues were higher in PFE than in GFE at 30 and 240 minutes after thawing. On the other hand, no significant differences were observed between GFE and PFE in ROS levels during freeze-thawing. In conclusion, PFE are less resistant than GFE to cryopreservation not only in terms of sperm motility and membrane integrity, but also in the integrity of nucleoprotein structure. However, this difference between PFE and GFE in the resistance of the nucleoprotein structure to freeze-thawing is not linked with concomitant changes in ROS levels.

Original publication

DOI

10.1016/j.theriogenology.2013.01.008

Type

Journal article

Journal

Theriogenology

Publication Date

01/04/2013

Volume

79

Pages

929 - 939

Keywords

Acrosome, Animals, Chromatin, Cryopreservation, DNA Fragmentation, Flow Cytometry, Male, Nucleoproteins, Reactive Oxygen Species, Semen Analysis, Semen Preservation, Swine