Cryopreservation of Danube barbel Barbus balcanicus sperm and its effects on sperm subpopulation structure

• Main Authors: Kojadinović Nataša M., Marinović Zoran, Veličković Tijana Z., Milošković Aleksandra M., Jakovljević Marija M., Horváth Ákos, Simić Vladica M.
• Format: Article
• Language: English
• Published: University of Belgrade, University of Novi Sad 2020-01-01
• Series: Archives of Biological Sciences
• Subjects: balkan barbel; spermatozoa; fish conservation; sperm subpopulation
• Online Access: http://www.doiserbia.nb.rs/img/doi/0354-4664/2020/0354-46642000046K.pdf
• ISSN: 0354-4664; 1821-4339

The objective of this study was to develop a successful freezing protocol for cryopreservation of Danube barbel sperm, and to identify the presence of different spermatozoa subpopulations. By testing different concentrations of different cryoprotectants, we determined that the use of 5% dimethyl sulfoxide (DMSO) yielded the highest total motility of ~25%. Cooling rates influenced by frame height and cooling time in liquid nitrogen vapor showed that a frame height of 3 cm and cooling time of 2 min yielded the highest post-thaw motility. Supplementation of cryomedia with 0.1 M of sugars led to an increase in the total post-thaw motility by ~50%, while protein supplementation lowered post-thaw motility. Motile spermatozoa hierarchically clustered according to their motility parameters, displaying a four-subpopulation (SP1-SP4) structure. SP1 was defined by low values of velocity but high overall linearity; SP2 was comprised of fast non-linear spermatozoa, that had high velocity values but low linearity; SP3 was characterized by fast linear spermatozoa, and SP4 by slow non-linear spermatozoa. Protocols developed in this study will lead to the creation of new and enhanced conservation strategies for this species.