TEMPORAL DYNAMICS OF HYPERACTIVATION OF RAM SPERMATOZOA AS A RESULT OF CHANGE IN THE KINEMATIC PARAMETERS

Abstract

The presented research is focused on the kinetic parameters of ram spermatozoa related to hyperactivation after incubation in Bovine serum albumine (BSA) -containing medium for 4 h. Seminal samples were collected from five sexually mature rams using artificial vagina. The ejaculates (n=15) were diluted with extender 6A, then incubated (37°C, 5% CO2 in air) for 4 hours in the absence (control group) or presence (experimental group) of 4 mg/ml BSA. The hyperactivation of the spermatozoa was detected using the Sperm computer analyser (SCA Microptic). Computer assisted sperm analysis (CASA) was performed for progressive and non-progressive motility and kinematic parameters of the sperm cells. The results demonstrated that incubation with BSA, resulted in a significant increase (P < 0,05) in the values of the kinetic parameters of spermatozoa at 4 h of incubation. The parameters that most accurately describe the hyperactivated motility are curvilinear velocity (VCL), percentage of fluctuation (WOB), amplitude of lateral displacement of the head (ALH), beat-cross frequency (BCF), velocity in a straight line (VSL), linearity (LIN) and straightness (STR). Our experiments display a significant decrease of the parameters VSL, LIN and STR (P < 0,05), which can also be related to the movement pattern of the cells characterized with hyperactivation. The incubation with BSA, under set conditions, resulted in the hyperactivation of ram spermatozoa with drastic changes in the following CASA parameters: VCL values > 100 μm/s, ALH > 7 μm, LIN < 50%, recorded at 4 h. The changes in sperm kinetics under the examined specific conditions can be used as a marker of hyperactivation of spermatozoa during the preparation process of media and diluents before artificial insemination.