Lectin based differential profiling of sperm membrane glycans for assessment of buffalo (Bubalus bubalis) bull fertility.

Spermatozoa membrane glycocalyx plays a crucial role in sperm functions, including maturation, female reproductive tract protection, oviductal epithelium adhesion, and oocyte fusion. This study investigated differences in glycan abundance and mapping in buffalo spermatozoa from high-fertile (HF) and low-fertile (LF) bulls. Semen samples were analyzed for motility, vitality, morphology, and functional characteristics before glycan profiling.

Surface N- or O-linked glycans on bovine spermatozoa play minimal role in evading macrophage mediated phagocytosis.

Bull spermatozoa possess glycocalyx made of carbohydrate moieties attached to proteins and lipids on their membranes that is involved in fertility associated functions including immune evasion in the female reproductive tract. The current study aimed to establish whether the differences in the glycocalyx of spermatozoa provide selective advantage in evading phagocytosis mediated by female macrophages. Based on removal of either N- or O-linked surface glycans from the spermatozoa, their susceptibility to phagocytosis by macrophages was assessed in bovines () through flow cytometry.

Extracellular vesicles in seminal plasma of Sahiwal cattle bulls carry a differential abundance of sperm fertility-associated proteins for augmenting the functional quality of low-fertile bull spermatozoa.

Poor male fertility significantly affects dairy production, primarily due to low conception rates (CR) in bulls, even when cows are inseminated with morphologically normal sperm. Seminal plasma is a key factor in evaluating the fertilizing ability of bull semen. The extracellular vesicles (EVs) in seminal plasma contain fertility-associated proteins like SPAM1, ADAM7, and SP10, which influence sperm function and fertilizing potential.

Higher abundance of DLD protein in buffalo bull spermatozoa causes elevated ROS production leading to early sperm capacitation and reduction in fertilizing ability.

Backgroud: Before fertilization, spermatozoa undergo a crucial maturation step called capacitation, which is a unique event regulates the sperm's ability for successful fertilization. The capacitation process takes place as the spermatozoa pass through the female reproductive tract (FRT). Dihydrolipoamide dehydrogenase (DLD) protein is a post-pyruvate metabolic enzyme, exhibiting reactive oxygen species (ROS) production which causes capacitation.