Effect Of Human Sperm Purified Mannose Receptor On Sperm-egg Fusion

In order to investigate the role of mannose receptor(MR) of human sperm ,the zona free hamster eggs were pre-incubated with purified MR(pMR) isolated from motile human sperm by mannose-agarose gel affinity chromatography.The ultrastuctural alteration and cortical granule exocytosis of the eggs were then observed by transmissian electron microscope and TRITC-LCA immunofluorescence microscope, respectively. The mice were immunized with pMR and the antiserum was raised. After capacitation and induction of the acrosome reaction, the human spermatozoa and oocytes were incubated with the antiserum.Then the sperm penetration assay was undertaken. The results were as follows:(l)The pre-incubation of pMR induced the exocytosis of the cortical granules(CGs)in the oocytes and reduced the quantity of the microvillus on the surface of oocytes;(2)The matrix of CG might migrate to the surface of plasma membrane of oocytes after pMR pre-treatment.(3)Incubation of zona-free hamster eggs with spermatozoa pretreated with pMR antiserum was associated with a dose-dependent significant reduction in the number of spermatozoa binding to the oolemma,compared with a contraband with a dose-dependent reduction of the fertilization rate and the penetration index.The results indicate that MR of human sperm plays an important role in sperm-oocyte fusion and oocyte activation.