Figure 5.

Fluorescence micrographs showing the test results for mitochondrial membrane potential ΔΨ_m and SMID_R assay. Boar spermatozoa were exposed to chaetoglobosin A (ChA) for two days at 24 °C. The sperm cells were stained with the membrane potentiometric dye JC-1 (top) and with the live–dead stain calcein-AM plus propidium iodide (PI) (bottom). The motile sperm cells in (A) and (E) were exposed to 1% ethanol as negative controls. (B–D,F) The sperm cells immobilized by ChA. The sperm cells in (A) exhibit high ΔΨ_m as indicated by the orange emission in the midpiece of the sperm flagellum; the green-staining sperm cells in (E) exhibit intact plasma membranes impermeable to the red stain PI. The red-staining sperm cells have lost their plasma membrane integrity and became permeable to PI. The sperm cells in (G,H) (positive controls for lethal toxicity) were exposed to alamethicin (Ala).