Seminal antigenicity affects mitochondrial membrane potential and acrosome reaction ability of the spermatozoa during cryopreservation

• Published in: Theriogenology Vol. 159; pp. 132 - 139
• Main Authors: Archana, Santhanahalli Siddalingappa, Selvaraju, Sellappan, Arangasamy, Arunachalam, Binsila, Balakrishnan, Swathi, Divakar, Ramya, Laxman, Kumaresan, Arumugam, Krishnappa, Balaganur
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-01-2021
• Subjects: Acrosome reaction; Anti-sperm antibody; Bulls; Cryopreservation; Semen antigenicity; Spermatozoa functional attributes; Bulls; Anti-sperm antibody; Acrosome reaction; Semen antigenicity; Spermatozoa functional attributes; Cryopreservation
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2020.10.025

The objective of this study was to assess the influence of spermatozoa surface antigenic proteins on the functional competence of bovine neat and frozen-thawed semen. The breeding bulls (n = 38) were screened for seminal antigenic levels in neat semen based on the agglutination titrations with anti-sperm antibody (ASA). Bulls having high (n = 8) and low (n = 7) antigenic levels were selected and spermatozoa functional parameters were analyzed in neat and frozen-thawed semen samples. In neat semen, kinematics such as straightness (73.6 ± 1.0 and 66.9 ± 1.5%), linearity (48.6 ± 1.2 and 40.1 ± 3.9%), curvilinear velocity (103.3 ± 2.6 and 93.4 ± 3.8 μm/s), straight-line velocity (65.7 ± 2.6 and 53.7 ± 2.2 μm/s) and average path velocity (53.8 ± 2.5 and 39.8 ± 2.3 μm/s) were significantly high (p < 0.05) in samples with lower antigenicity. The percentage of spermatozoa that can penetrate mucus (49.9 ± 2.3 and 37.1 ± 3.2) was significantly higher in semen samples with low ASAs. The total motile (84.0 ± 2.5 and 86.0 ± 1.5) and progressive motile (68.4 ± 3.7 and 69.2 ± 1.6) spermatozoa were higher in neat semen samples with higher antigenicity. A significantly (p < 0.05) higher mitochondrial membrane potential was observed in neat (82.5 ± 2.8 and 69.0 ± 2.0%) and post-thaw (28 ± 5. 6 and 16 ± 3.7%) samples of the lower antigenic group. The percentage of acrosome-reacted spermatozoa was significantly (p < 0.05) higher in neat (58.7 ± 2.9 and 52.6 ± 1.8), but reduced significantly (p < 0.05) in post-thaw (32.0 ± 2.0 and 48.0 ± 2.6) semen of higher antigenic groups. The study reveals that higher seminal antigenicity reduces mitochondrial membrane potential and acrosome reaction ability in post-thaw spermatozoa.
•Higher levels of seminal antigen affect spermatozoa kinematics and mitochondrial membrane potential in neat semen.•Levels of seminal antigens did not influence spermatozoa kinematics in post-thaw semen samples.•Seminal antigenicity did not influence spermatozoa structural and functional membrane integrities during cryopreservation.•Higher levels of seminal antigens prevent acrosome reaction in post-thaw spermatozoa.•Antigenic levels in semen may affect the fertilization competence of frozen semen samples.