title: Binding of Sperm to the Zona Pellucida Mediated by Sperm Carbohydrate-Binding Proteins is not Species-Specific in Vitro between Pigs and Cattle.
abstract: Carbohydrates are candidates for the basis of species-selective interaction of gametes during mammalian fertilization. In this study, we sought to clarify the roles of sugar residues in the species-selective, sperm-oocyte interaction in pigs and cattle. Acrosome-intact porcine and bovine sperm exhibited their strongest binding affinities for β-Gal and α-Man residues, respectively. Porcine-sperm specificity changed from β-Gal to α-Man after the acrosome reaction, while bovine-sperm specificity did not. Binding of acrosome-intact and acrosome-reacted sperm decreased after trypsinization, indicating that the carbohydrate-binding components are proteins. While immature oocytes bound homologous sperm preferentially to heterologous sperm, oocytes matured in vitro bound similar numbers of homologous and heterologous sperm. Lectin staining revealed the aggregation of α-Man residues on the outer surface of the porcine zona during maturation. In both species, zona-free, mature oocytes bound homologous sperm preferentially to heterologous sperm. The lectin-staining patterns of the zona pellucida and zona-free oocytes coincided with the carbohydrate-binding specificities of acrosome-intact and acrosome-reacted sperm, respectively, supporting the involvement of carbohydrates in gamete recognition in pigs and cattle. These results also indicate that sperm-zona pellucida and sperm-oolemma bindings are not strictly species-specific in pigs and cattle, and further suggest that sperm penetration into the zona and/or fusion with oolemma may be species-specific between pigs and cattle.
authors: Graduate School of Science, Chiba University, Chiba 263-8522, Japan. zag21019@gmail.com.
authors: Kazuya
authors: K
authors: Takahashi
authors: National Institute of Agrobiological Sciences, Ibaraki 305-8602, Japan. kiku@affrc.go.jp.
authors: Kazuhiro
authors: K
authors: Kikuchi
authors: Graduate School of Science, Chiba University, Chiba 263-8522, Japan. yasu-omi.dear@ezweb.ne.jp.
authors: Yasuomi
authors: Y
authors: Uchida
authors: Graduate School of Science, Chiba University, Chiba 263-8522, Japan. s_kitayama@kyoritsuseiyaku.com.
authors: Saeko
authors: S
authors: Kanai-Kitayama
authors: Graduate School of Science, Chiba University, Chiba 263-8522, Japan. suzuki_016@hotmail.com.
authors: Reiichiro
authors: R
authors: Suzuki
authors: The Noguchi Institute, Tokyo 173-0003, Japan. resato@noguchi.or.jp.
authors: Reiko
authors: R
authors: Sato
authors: The Noguchi Institute, Tokyo 173-0003, Japan. toma.kb@om.asahi-kasei.co.jp.
authors: Kazunori
authors: K
authors: Toma
authors: National Institute of Livestock and Grassland Science, Ibaraki 305-0901, Japan. geshi@affrc.go.jp.
authors: Masaya
authors: M
authors: Geshi
authors: National Institute of Livestock and Grassland Science, Ibaraki 305-0901, Japan. akagi@affrc.go.jp.
authors: Satoshi
authors: S
authors: Akagi
authors: Graduate School of Science, Chiba University, Chiba 263-8522, Japan. mnakano-1359@dgs.nir.jp.
authors: Minoru
authors: M
authors: Nakano
authors: Graduate School of Science, Chiba University, Chiba 263-8522, Japan. nyoneza@faculty.chiba-u.jp.
authors: Naoto
authors: N
authors: Yonezawa