Fig. 9

Acrosome integrity and capacitation status of the canine post-thaw sperm evaluated by CTC staining after cryopreservation in extenders containing different levels of melatonin versus the control groups. One-way ANOVA statistical test was used to make a comparison between treatment groups and the LSD posthoc test was used to perform pairwise comparisons. Different letters in bar superscripts indicate a statistically significant difference (P ≤ 0.05). Negative Control (without Melatonin or DMSO), Positive Control (containing DMSO), M1 (containing 0.5 mM Melatonin), M2 (containing 1 mM Melatonin), and M3 (containing 2 mM Melatonin). All numbers are presented as Means±SEM. Pattern F = non-capacitated with intact acrosome, pattern B = capacitated with intact acrosome, and Pattern AR = reacted/damaged acrosome, CTC=Chlortetracycline