Evaluation of bull spermatozoa during and after cryopreservation: Structural and ultrastructural insights

Publication date: 2018Source: International Journal of Veterinary Science and Medicine, Volume 6, SupplementAuthor(s): Wael A. Khalil, Mostafa A. El-Harairy, Alaa E.B. Zeidan, Mahmoud A.E. Hassan, Omnia Mohey-ElsaeedAbstractSemen cryopreservation is a well-established procedure used in veterinary assisted reproduction technology applications. We investigated damaging effects of cryopreservation on the structural and ultrastructural characteristics of bull sperm induced at different temperatures and steps during standard cryopreservation procedure using transmission (TEM) and scanning electron microscopy. We also examined the effect of cryopreservation on sperm DNA and chromatin integrity. Five healthy, fertile Friesian bulls were used, and the ejaculates were obtained using an artificial vagina method. The semen samples were pooled and diluted in a tris-yolk fructose (TYF) for a final concentration of 80 × 106 spermatozoa/ml. The semen samples were packed in straws (0.25 ml), and stored in liquid nitrogen (−196°C). Samples were evaluated before dilution, just after dilution (at 37°C), at 2 h and 4 h during equilibration, and after thawing (37°C for 30 s in water bath). In association with step-wise decline in motility and viability, our results showed that the plasma membrane surrounding the sperm head was the most vulnerable structure to cryo-damage with various degrees of swelling, undulation, or loss affecting about 50% of the total sperm population aft...
Source: International Journal of Veterinary Science and Medicine - Category: Veterinary Research Source Type: research