Sperm Response to in vitro Stress Conditions in Wild and Domestic Species Measured by Functional Variables and ROS Production

Abstract

The domestication process has resulted in profound changes in the reproductive physiology of the animals that might have affected the sperm characteristics and thus their sensitivity to handling and cryopreservation procedures. This work assesses the response of the sperm of domestic and wild ungulates to a cooling storage at 15°C for 20 h followed by incubation at 38.5°C, 5% CO2, for 2 h. In addition, this paper examines the most representative sperm traits to assess their responsiveness to these stress conditions. Sperm samples were collected from domestic and their wild ancestor species: ram, mouflon, buck, Iberian ibex, domestic boar, and wild boar. Sperm motility, viability, mitochondrial membrane status, DNA fragmentation, and reactive oxygen species production were evaluated at the beginning of the experiment, after 20 h of refrigeration at 15°C, and, finally, at 2 h of incubation at 38.5°C. Sperm from all domestic species (ram, buck, and domestic boar) suffered more stress than their wild relatives (mouflon, Iberian Ibex, and wild boar). In pigs, the percentage of intact mitochondria was lower in the domestic species compared to wild boar. In sheep, we found a higher reactive oxygen species production in rams, while in goats, the curvilinear velocity was lower in the domestic species. The PCA (principal components analysis) showed that the motility and their kinetic variables were the most represented variables in the principal components of all species, indicating that they are essential biomarkers for evaluating the stress response. Sperm viability was highlighted as a representative variable for evaluating the stress response in domestic boar, mouflon, ram, and ibex.

Assessment of semen quality and anti‐oxidative enzyme activity between bovine sex‐sorted and non‐sex‐sorted frozen–thawed semen

“…The flow cytometric sperm sorter method separates X and Y chromosomes bearing spermatozoa based on the DNA (Carvalho et al, 2010; Obuchi et al, 2019). Although, semen sex preselection has proven to be effective in cattle, sheep and pig (González‐Marín et al, 2018; O'Brien et al, 2021), however, sex‐sorted spermatozoa have worse sperm survival and quality characteristics than non‐sorted spermatozoa (Espinosa‐Cervantes & Córdova‐Izquierdo, 2012). Our results showed that the quality of non‐sexed semen was better than the sexed semen in terms of sperm motility, movement, acrosomal and membrane integrity and the rate of IVF.…”

Exogenous spermidine effectively improves the quality of cryopreserved boar sperm

“…Although liquid‐stored boar semen is most commonly used for AI, there are problems with short shelf life and bacterial growth (Morrell, 2016). The quality of cryopreserved boar sperm is inferior compared to other domestic animals, mainly due to high unsaturated phospholipid content and low cholesterol content in the membrane (Basioura et al, 2020; O'Brien et al, 2021). Convenient long‐distance transportation and long preservation time remain the advantages of cryopreserving boar sperm (Waberski et al, 2019).…”