title: Roles of mouse sperm-associated alpha-L-fucosidases in fertilization.
abstract: Sperm-associated α-L-fucosidases have been implicated in fertilization in many species. Previously, we documented the existence of α-L-fucosidase in mouse cauda epididymal contents, and showed that sperm-associated α-L-fucosidase is cryptically stored within the acrosome and reappears within the sperm equatorial segment after the acrosome reaction. The enrichment of sperm membrane-associated α-L-fucosidase within the equatorial segment of acrosome-reacted cells implicates its roles during fertilization. Here, we document the absence of α-L-fucosidase in mouse oocytes and early embryos, and define roles of sperm associated α-L-fucosidase in fertilization using specific inhibitors and competitors. Mouse sperm were pretreated with deoxyfuconojirimycin (DFJ, an inhibitor of α-L-fucosidase) or with anti-fucosidase antibody; alternatively, mouse oocytes were pretreated with purified human liver α-L-fucosidase. Five-millimolar DFJ did not inhibit sperm-zona pellucida (ZP) binding, membrane binding, or fusion and penetration, but anti-fucosidase antibody and purified human liver α-L-fucosidase significantly decreased the frequency of these events. To evaluate sperm-associated α-L-fucosidase enzyme activity in post-fusion events, DFJ-pretreated sperm were microinjected into oocytes, and 2-pronuclear (2-PN) embryos were treated with 5 mM DFJ with no significant effects, suggesting that α-L-fucosidase enzyme activity does not play a role in post-fusion events and/or early embryo development in mice. The recognition and binding of mouse sperm to the ZP and oolemma involves the glycoprotein structure of α-L-fucosidase, but not its catalytic action. These observations suggest that deficits in fucosidase protein and/or the presence of anti-fucosidase antibody may be responsible for some types of infertility.
authors: Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
authors: Kamonrat
authors: K
authors: Phopin
authors: Wutigri
authors: W
authors: Nimlamool
authors: Linda J
authors: LJ
authors: Lowe-Krentz
authors: Elijah W
authors: EW
authors: Douglass
authors: Jaclyn N
authors: JN
authors: Taroni
authors: Barry S
authors: BS
authors: Bean
mesh_terms: D017485:1-Deoxynojirimycin / Q000031:analogs & derivatives / Q000494:pharmacology; D000177:Acrosome / Q000378:metabolism*; D020101:Acrosome Reaction / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007246:Infertility / Q000209:etiology / Q000378:metabolism; D008297:Male; D051379:Mice; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D013402:Sugar Alcohols / Q000494:pharmacology; D005644:alpha-L-Fucosidase / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D013402:Sugar Alcohols; D017485:1-Deoxynojirimycin; C062662:deoxyfuconojirimycin; D005644:alpha-L-Fucosidase