The synergistic effect of trehalose and low concentrations of cryoprotectants can improve post-thaw ram sperm parameters


Ozturk A. E. , Bodu M., Bucak M. N. , Agir V., Ozcan A., Keskin N., ...More

CRYOBIOLOGY, vol.95, pp.157-163, 2020 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 95
  • Publication Date: 2020
  • Doi Number: 10.1016/j.cryobiol.2020.03.008
  • Title of Journal : CRYOBIOLOGY
  • Page Numbers: pp.157-163
  • Keywords: Ram semen, Glycerol, Ethylene glycol, Sperm parameters, Trehalose, OXIDATIVE STRESS PARAMETERS, COMPARING ETHYLENE-GLYCOL, EGG-YOLK, MAMMALIAN SPERM, COOLING RATE, BULL SEMEN, CRYOPRESERVATION, GLYCEROL, FROZEN, MEMBRANE

Abstract

The objective of this study was to compare the effects of different concentrations of two different cryoprotectants (glycerol, G and ethylene glycol, EG) and trehalose (T), added to the semen extender, on post-thaw ram sperm parameters. Ejaculates, collected from 6 Merino rams, were pooled and evaluated at 37 degrees C. The pooled samples were divided into six equal aliquots, and diluted in Tris-based extenders containing 5% G, 3% G + 60 Mm T, 1.5% G + 100 Mm T, 5% EG, 3% EG + 60 mM T, and 1.5% EG + 100 Mm T. Subsequently, the samples were cooled to 5 degrees C, frozen in 0.25-ml French straws, and stored in liquid nitrogen (LN2). Frozen samples were thawed individually, at 37 degrees C for 25 s in a water bath, for evaluation. Sperm motility was assessed using a phase-contrast microscope with a warm stage maintained at 37 degrees C. Acrosome integrity (FITC/PNA-PI), sperm viability (SYBR-14/PI), mitochondrial activity (JC-1/PI), DNA damage (COMET assay) and DNA fragmentation (TUNEL test) were determined. The group of samples diluted in an extender containing 5% of glycerol (Group 5% G) displayed higher percentages of subjective motility, viability and mitochondrial activity of sperm, compared to the other groups (P < 0.05). On the other hand, Group 3% G + 60 Mm T yielded the second-best results for subjective motility, viability and mitochondrial activity of sperm, when compared to the other groups. The post-thaw sperm parameters of Group 3% G + 60 Mm T did not show any statistically significant difference from those of Group 5% G. There were no statistically significant differences between the groups for acrosome integrity (P > 0.05).