Association between the extent of DNA damage in the spermatozoa, fertilization and developmental competence in preimplantation stage embryos

Abstract

Objective: To examine the fertilizing ability and DNA damage response of preimplantation stage embryos derived from the γ-irradiated mouse sperm carrying varying amounts of DNA strand-breaks. Material and Methods:The DNA damage in the sperm was induced by exposing the testicular area to different doses of γ-radiation. After mating with healthy female mice, sperm zona binding, fertilizing ability of DNA damaged sperm and developmental competence of embryos derived from the DNA damaged sperm were assessed. Results:The in vivo zona binding ability and fertilizing ability of DNA damaged sperm was significantly affected in the 5.0 and 10.0 Gy sperm irradiation groups. Although the development of the embryos derived from the DNA damaged sperm was not significantly affected until day 2.5 post-coitus, further development was significantly altered, as evidenced by the total cell number in the embryos. Conclusion:The sperm carrying DNA strand breaks still has the ability to fertilize the oocyte normally. However, the events like zona-binding and successful fertilization depend on the extent of sperm DNA fragmentation. The study has also showed a great heterogeneity in embryonic development at peri-implantation period with respect to the degree of sperm DNA damage. (J Turkish-German Gynecol Assoc 2010; 11: 182-6) Key words: Sperm DNA damage, fertilization, preimplantation development Received: 1 July, 2010 Accepted: 24 August, 2010 Amaç: Gama ışınları ile ışınlanmış ve değişen miktarda DNA zincir kı-rığı taşıyan fare sperminin dölleme yeteneğini ve bu spermlerden oluşan implantasyon öncesi embriyoların DNA hasarı yanıtını incelemek. Gereç ve Yöntemler:Spermde DNA hasarı, testiküler bölgenin farklı dozlarda gama ışınlarına maruz bırakılmasıyla indüklendi. Sağlıklı dişi fareler ile çiftleşmeden sonra, sperm-zona bağlanması, DNA hasarlı spermin dölleme yeteneği ve DNA hasarlı spermden oluşan embriyoların gelişimsel kompetansı değerlendirildi.Bulgular: 5.0 ve 10.0 Gy ışın uygulanan gruplarda, DNA hasarlı spermin in vivo zona bağlanma yeteneği ve dölleme yeteneği anlamlı olarak etkilendi. DNA hasarlı spermden oluşan embriyoların gelişimi koitus sonrası 2.5 güne kadar anlamlı ölçüde etkilenmemekle beraber, sonraki gelişim embriyolardaki toplam hücre sayısından anlaşılacağı gibi anlamlı olarak değişti.Sonuç: DNA zincir kırıkları taşıyan sperm hala oositi normal bir şekil-de dölleme yeteneğine sahiptir, bununla beraber, zona-bağlanması ve başarılı fertilizasyon gibi olaylar sperm DNA parçalanmasının boyutuna bağlıdır. Çalışma ayrıca peri-implantasyon döneminde embriyonik gelişimde sperm DNA hasarının derecesine ilişkin olarak büyük bir heterojenlik göstermiştir.

Effect of cryoprotectant on the motility, viability, fertilization, and DNA integrity of naleh fish Barbonymus sp. (Cyprinidae) sperm

“…Besides, damage to the DNA does not always affect motility and fertility, as seen in brown-marbled grouper, Epinephelus fuscoguttatus (Yusoff et al, 2018). Upadhya et al (2010) found that the affected sperm with good motility possess the capacity to fertilize an egg, followed by the development of potentially damaged genomes, and, consequently, causing larvae abnormality. Horvath & Urbanyi (2001) recorded higher amounts of abnormal larvae in eggs fertilized using cryopreserved sperm, of which some were haploid (Miskolczi et al, 2005).…”

Combination of swim-up and density gradient separation methods effectively eliminate DNA damaged sperm

“…Sperm DNA integrity is essential for accurate transmission of genetic material to the offspring (3). It has been shown that paternal DNA damage can lead to pre-implantation developmental delay and compromised post-implantation developmental potential in mice (4)(5)(6). Hence sperm preparation method for assisted reproduction techniques should aim at minimizing the potential risk caused by abnormal sperm on the outcome.…”