Mammalian spermatozoa are not mature when they leave the testis, the development continues during their passages through the epididymis. Epididymis secrets glycoproteins into the luminal fluid, and creates a microenvironment of the epididymis, which is necessary for spermatozoa maturation, acquiring forward motility and fertility potential. Lately, it is found that in human seminal plasma there has very high concentration of free oligosaccharides (0.3-0.4mg/ml) which is rich in fucose carried Le~X and Le~Y epitopes and assumed that free oligosaccharides may be involved in increasing sperm longevity, modifying sperm motion, promoting sperm binding to eggs in oviduct and increasing immunosuppressive activity of sperm. But the source, distribution and function of the fucosylated oligosaccharides are still unclear. This study mainly uses Le~X and Le~Y antibodies to identify the expression and distribution of the two antigens in mouse by immunohistochemistry analysis. The results reveal that Le~X and Le~Y are negative in the testis, but dramatically turn to strong expression in the caput epididymis, where luminal sperm become positive staining, too. Except some apical cells and clear cells, the expressions of majority positive cells weaken from caput to cauda. Le~X and Le~Y are also light positive in the lumen of vas deferens, but Le~Y is abundantly expressed in the epithelium of seminal vesicles. According to our preliminary results, the expressions of the two antigens in mouse are similar with those in human. It is indicated that Le~X and Le~Y are mainly synthesized and secreted by the caput epididymis and may be coated the sperm surface in lumen, and the fucosylated oligosaccharides in seminal plasma may come from epididymis. Le~Y may also come from the seminal vesicles. Further investigation will be required to speculate the biological significance of fucosylated oligosaccharides in male reproduction.
展开▼
