Effect Of Freezing Rate On Acrosome And Chromatin Integrity In Ram Semen

• Published in: Veteriner Fakültesi dergisi Vol. 58; no. 4
• Main Authors: Doğan,İbrahim, Zık,Berrin, Tütüncü,Şerife, Nur,Zekariya, Ustuner,Burcu, Sagırkaya,Hakan, Ozguden,Cansel G, Gunay,Ulgen
• Format: Journal Article
• Language: English
• Published: Ankara Üniversitesi Veteriner Fakültesi 01.04.2011
• Subjects: Sağlık Hizmetleri; Tıp; Ankara; Türkiye; freezing rate; apoptozis; Koç sperması; ram semen; dondurma hızı; Apoptosis
• ISSN: 1300-0861; 1308-2817
• DOI: 10.1501/vetfak_0000002486

The objective of the present study was to investigate the effect of different freezing rates on post-thaw sperm motility, acrosome defect, and sperm chromatin structure and apoptotic activity in ram semen. Collected semen was diluted at 1:5 (semen/extender) with Bioxel® (IMV technologies France) at 30°C and then cooled to 5°C within 1h. Cooled semen was subjected to the equilibration for 2 hours. Equilibrated semen was frozen in 0.25 ml straw at two different cooling rates (slow: 0.5°C/min from 5 to -20°C and fast: 5°C/min from 5 to -20°C). Both groups were frozen from -20 to -120°C at 25°C/min and stored in liquid nitrogen until use. Post-thaw (37°C/30 min) sperm motility, defected acrosome (Pisum sativum agglutinin fluorescein conjugate, FITC PSA), sperm chromatin structure determined by Acridin Orange (AO) and apoptotic activity using terminal deoxynucleotidyl transferase- mediated dUTP nick-end labeling (TUNEL) were evaluated. Post-thaw sperm motility, acrosome defect, AO and TUNEL for slow frozen semen were 42.8±8.8%, 31.6±12.9%, 2.9±2.4% and 2.8±1.6%, and for fast frozen semen were 36.5±9.9%, 24.7±11.1%, 3.3±2.2% and 6.3±3.4%, respectively. Post-thaw semen analyses showed that there was no significant difference between two freezing curves in terms of acrosome defect, sperm chromatin damage (AO). However, a significant difference was found for postthaw semen motility between two groups (P<0.05). In conclusion, while the slow freezing procedure improved post-thaw sperm motility, acrosome and chromatin integrities and apoptotic index in ram spermatozoa did not show any significant difference between freezing rates.