Seminal plasma applied post-thawing affects boar sperm physiology: A flow cytometry study

Abstract

Cryopreservation induces extensive biophysical and biochemical changes in the sperm. In the present study, we used flow cytometry to assess the capacitation-like status of frozen-thawed boar spermatozoa and its relationship with intracellular calcium, assessment of membrane fluidity, modification of thiol groups in plasma membrane proteins, reactive oxygen species (ROS) levels, viability, acrosomal status, and mitochondrial activity. This experiment was performed to verify the effect of adding seminal plasma on post-thaw sperm functions. To determine these effects after cryopreservation, frozen-thawed semen from seven boars was examined after supplementation with different concentrations of pooled seminal plasma (0%, 10%, and 50%) at various times of incubation from 0 to 4 hours. Incubation caused a decrease in membrane integrity and an increase in acrosomal damage, with small changes in other parameters (P > 0.05). Although 10% seminal plasma showed few differences with 0% (ROS increase at 4 hours, P < 0.05), 50% seminal plasma caused important changes. Membrane fluidity increased considerably from the beginning of the experiment, and ROS and free thiols in the cell surface increased by 2 hours of incubation. By the end of the experiment, viability decreased and acrosomal damage increased in the 50% seminal plasma samples. The addition of 50% of seminal plasma seems to modify the physiology of thawed boar spermatozoa, possibly through membrane changes and ROS increase. Although some effects were detrimental, the stimulatory effect of 50% seminal plasma could favor the performance of post-thawed boar semen, as showed in the field (García JC, Domínguez JC, Peña FJ, Alegre B, Gonzalez R, Castro MJ, Habing GG, Kirkwood RN. Thawing boar semen in the presence of seminal plasma: effects on sperm quality and fertility. Anim Reprod Sci 2010;119:160-5).

Fusion of Boar Sperm with Nanoliposomes Prepared from Synthetic Phospholipids

“…This high fusion efficiency far exceeds the 2% of live bull sperm and 18% of dead bull sperm observed to fuse with liposomes made from PS and cholesterol (Fernández‐Gago et al. ) and is notably higher than the 40–60% of boar sperm that fused with quite similar mixed‐phospholipid liposomes (He et al. ).…”

Cryopreservation of sperm in annual fish Austrolebias minuano (Cyprinodontiformes; Rivulidae)

“…Ten (10) µL of the thawed sample was stained with 2.7 μM of a hydrophobic merocyanine dye 540 (M540) and 0.1 μM of YO‐PRO‐1 (Invitrogen‐Eugene) for 5 min. High M540‐positivity (high membrane fluidity) and low M540‐positivity (low membrane fluidity) were evaluated only for intact spermatozoa (YO‐PRO‐1 negative; Fernández‐Gago, Domínguez, & Martínez‐Pastor, ). Membrane fluidity rate was defined as: [Number of high M540‐positive events/Total number of M540‐positive events] × 100.…”

Toxic effects of mercury chloride on silver catfish (Rhamdia quelen ) spermatozoa

“…The working solution used for spermatozoa staining was composed of phosphate buffered saline (PBS), Hoechst 33342 (16.2 μM), CFD (20 μM), and PI (7.3 μM). Spermatozoa were classified as non‐damaged (CFD+/PI) or damaged (CFD+/PI+; CFD−/PI+; CFD−/PI) (Fernández‐Gago, Domínguez, & Martínez‐Pastor, ; Gillan, Evans, & Maxwell, ).…”