Affinity of Abelmoschus Esculentus Lectin for the Midpiece of Ovine Spermatozoa and Its Effects on Functional Parameters

Lectins are carbohydrate-binding proteins that recognize specific glycan patterns on cell surfaces and have been increasingly explored as analytical tools in reproductive biology. This study characterized the interaction of a lectin isolated from Abelmoschus esculentus seeds (AEL) with ovine spermatozoa and evaluated its compatibility with sperm functional parameters during short-term refrigeration. Eighteen ejaculates were diluted in a Tris–egg yolk extender supplemented with 0, 1, or 3 µg/mL AEL and stored at 5°C for 24 h. Sperm motility (CASA) and flow cytometry were used to assess plasma membrane integrity and fluidity, mitochondrial membrane potential, and reactive oxygen species production. Confocal microscopy was performed to determine the localization pattern of AEL binding. AEL labeling was predominantly restricted to the sperm midpiece region. Supplementation with AEL at the tested concentrations did not affect motility patterns, membrane integrity, mitochondrial membrane potential, or ROS levels after 24 h of storage (p > 0.05). These findings indicate that AEL exhibits a consistent midpiece-associated binding pattern and does not compromise sperm functional parameters under refrigerated conditions. The results support the use of AEL as a compatible probe for investigating glycan distribution in the midpiece region of ram spermatozoa.