Author
|
Submitted to: Theriogenology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/9/2008 Publication Date: 5/30/2008 Citation: Purdy, P.H. 2008. Ubiquitination and its influence in boar sperm physiology and cryopreservation. Theriogenology 70:818-826. Interpretive Summary: The amount of ubiquitination is negatively and positively associated with sperm quality, but its effects on boar sperm physiology are largely unknown. This research determined the influence of boar sperm ubiquitination on motility, mitochondrial activity, plasma and acrosomal membrane integrity, membrane fluidity, and DNA stability for fresh and frozen-thawed samples. The effects of ubiquitination on the ability of frozen-thawed boar sperm to capacitate, acrosome react, and bind to membranes were also investigated. Freezing induced a loss in the percentage of ubiquitinated sperm from 29% to 20%. A negative correlation was found between the percentage of ubiquitinated sperm and chromatin damage after cryopreservation. Positive correlations between ubiquitinated, DNA damaged sperm and post-thaw motility, progressive motility, and plasma membrane integrity were also detected. The ability of sperm to capacitate and acrosome react or bind to membranes were not influenced by ubiquitination. Contrary to other findings, these results illustrate that boar sperm ubiquitination correlates with lower incidences of DNA damage, higher percentages of motile sperm, and higher percentages of cells with intact plasma membranes. Technical Abstract: The amount of ubiquitination correlates both negatively and positively with sperm quality, but its effects on boar sperm physiology are largely unknown. This research determined the influence of boar sperm ubiquitination (n = 12) on motility, mitochondrial activity, plasma and acrosomal membrane integrity, membrane fluidity, and chromatin stability (TUNEL) for fresh and frozen-thawed samples. The effects of ubiquitination on the ability of frozen-thawed boar sperm to capacitate, acrosome react, and bind to the perivitelline membrane were also investigated. Cryopreservation induced a significant loss in the percentage of ubiquitinated sperm from 29% to 20% (P < 0.0001). A negative correlation (P < 0.05) was found between the percentage of single-stained (single parameter ubiquitin analysis) ubiquitinated sperm and chromatin damage (r = -.65) after cryopreservation. Positive correlations between of dual-stained (ubiquitin and TUNEL) ubiquitinated sperm and post-thaw motility, progressive motility, and plasma membrane integrity (r = .72, .63, .64, respectively) were also detected. The ability of sperm to capacitate and acrosome react or bind to the perivitelline membrane were not influenced by ubiquitination (P > 0.05). Contrary to other findings, these results illustrate that boar sperm ubiquitination correlates with lower incidences of chromatin damage, higher percentages of motile sperm, and higher percentages of cells with intact plasma membranes. |
