title: Effect of freezing on sperm nuclear DNA.
abstract: Sperm DNA damage has a significant impact on reproductive outcomes. In recent years, the search for optimal molecular markers for the evaluation of semen quality has resulted in the increased focus on sperm nuclear DNA assessment. The primary aim of this article was to review and summarize the effects of freezing-thawing procedure on nuclear DNA integrity of boar spermatozoa. Using different sperm DNA integrity assays, it has been confirmed that the sperm DNA undergoes structural changes during the freezing-thawing process. Evidence has been shown that a significant proportion of frozen-thawed spermatozoa with compromised chromatin integrity was highly susceptible to DNA fragmentation. Moreover, the possible mechanisms responsible for post-thaw sperm DNA damage could be because of cryo-induced oxidative stress and, to a lesser extent, to the activation of an apoptotic-like phenomenon. This review also highlights the ongoing effort employed to develop optimal strategies to reduce sperm DNA damage following freezing-thawing of boar semen.
authors.affiliation: Department of Animal Biochemistry and Biotechnology, University of Warmia and Mazury in Olsztyn, Poland. fraser@uwm.edu.pl
authors.forename: L
authors.initials: L
authors.lastname: Fraser
authors.forename: J
authors.initials: J
authors.lastname: Strzeżek
authors.forename: W
authors.initials: W
authors.lastname: Kordan
mesh_terms: D000818:Animals; D004249:DNA Damage; D005615:Freezing; D007315:Insemination, Artificial / Q000662:veterinary; D008297:Male; D012662:Semen Preservation / Q000662:veterinary; D013094:Spermatozoa / Q000502:physiology*; D013552:Swine / Q000502:physiology*