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. Utilizing group of nine different lectins through cytochemistry and flow cytometry analyses we identified differentially abundant glycans (DAGs) on sperm membrane. HF bulls exhibited superior sperm quality and significantly higher glycan abundance than LF bulls. MAL-II (Maackia amurensis lectin II) depicted stronger binding affinity with HF sperm indicating a higher presence of α-2,3-linked sialic acid residues crucial for sperm function. JAC (Artocarpus integrifolia) binding revealed an abundance of N-acetylgalactosamine, while ABL (Agaricus bisporus lectin) indicated greater mannose-containing glycoconjugates in HF sperm. The glycan map of buffalo spermatozoa underscores a higher abundance of α-2,3-linked sialic acids and acetylgalactosamine in HF sperm, highlighting the potential role of glycan profiling as a screening tool for selecting highly fertile bulls. The findings of this study can pave the way to develop a fertility prediction tool as a rapid lab-on-strip device for enhancing the reproductive and breeding performance of buffalo bulls.