Buffalo sperm surface proteome profiling reveals an intricate relationship between innate immunity and reproduction

Abstract Background Low conception rate (CR) despite insemination with morphologically normal spermatozoa is a common reproductive restraint that limits buffalo productivity. This accounts for significant loss to the farmers and dairy industry, especially in agriculture-based economies. The immune-related proteins on sperm surface are known regulate fertility by assisting their survival performance female tract (FRT). Regardless of importance, very few studies have specifically catalogued proteome. study was designed determine identity ascertain if epididymal expressed beta-defensins (BDs), implicated male fertility, translated applied onto along other proteins. Results raw mass spectra data searched against an in-house generated proteome database from UniProt using Comet search engine identified more than 300 ejaculated which were bound either non-covalent (ionic) interactions or glycosylphosphatidylinositol (GPI) anchor. singular enrichment analysis (SEA) revealed most these extracellular varied binding activities involved immune processes. Flow cytometry six FITC-labelled lectins confirmed prediction glycosylation Several anti-microbial peptides including BuBD-129 126 also amongst presence subsequently RT-qPCR, immunofluorescence vitro fertilization (IVF) experiments. Conclusions heavily glycosylated because secreted (glyco) like BDs GPI-anchored (GPI-APs). pattern sperm-surface, however, could be perturbed elevated salt concentration incubation PI-PLC. identification numerous strengthens our hypothesis (BuBDs) assist FRT. Our results suggest sperm-surface BD role function. Further elucidating its exact physiological function required better understand regulation fertility.