Mercury-Induced Inhibition of Tyrosine Phosphorylation of Sperm Proteins and Altered Functional Dynamics of Buck Spermatozoa: an In Vitro Study

Collapsed mitochondrial cristae in goat spermatozoa due to mercury result in lethality and compromised motility along with altered kinematic patterns

“…Thus, our CASA data evidently suggests that mercury directly diminishes the ability of sperms to penetrate and fuse with oocytes. Our observations of the kinematic patterns also validate our earlier finding 13 in which we did not observe any capacitation in sperms following exposure to mercuric chloride at 1.25 µg/ml for 15 min and 3 h.…”

“…The study was undertaken in four treatment groups using four different concentrations of mercury chloride (0.031, 0.125, 0.25 and 1.25 μg/ml) and one control group (PBS + 0.5% glucose). These concentrations of mercuric chloride were 1/40th, 1/10th, 1/5th and equivalent to the LC 50 value of HgCl 2 for goat spermatozoa 13 .…”

“…In our recent publication, we have reported mercury-induced significant increase in ROS and MDA, significant decrease in TAC and SOD activity, significant decrease in spontaneous acrosome reaction, and inhibited capacitation in sperm cells despite increase in cAMP and intracellular Ca 2+ levels even at 0.031 µg/ml compared to the control group after 15 min exposure. Based on these findings, we proposed that oxidative stress causes alterations in sperm functions 13 possibly by affecting sperm membrane as well as sub-cellular structures. To substantiate our proposed mechanism of mercury-induced alterations in functional dynamics of spermatozoa, present study was undertaken to understand how cell death takes place and what changes take place in sperms at molecular and ultra-microscopic levels, especially at organelle level, that affect the motility and kinematic patterns in an endeavour to give a fillip to our understanding about mercury-induced cell death and alterations in functional dynamics of spermatozoa.…”

“…To determine the percentage of live spermatozoa in semen samples following in vitro exposure to different concentrations of mercury chloride (0.031, 0.125, 0.25 and 1.25 μg/ml) for different time intervals (15 min, 1 h and 3 h), smears from semen samples of different groups were prepared, air-dried and then stained with Eosin-Nigrosin employing the method of Hancock 24 as briefly described by us in our recent publication 13 .…”

“…Concentration of spermatozoa in semen samples were determined using hemocytometer (Improved Neubauer's chamber). Semen samples were diluted using semen dilution medium (phosphate buffer solution containing 0.5% glucose and of pH 7) as described earlier 13 to obtain the final working concentration of 50 × 10 6 spermatozoa/ml. Experimental design.…”