Studies on Sperm Function in Fertilization

To elucidate the sperm function (sperm/egg interaction) in mammalian fertilization我们carried out biochemical and biological experiments using genetically modified mutant mice，1) To elucidate the role of acrosin in fertilization，我们已经做了acrosin in the acrosome reaction of sperm，using the acrosin-deficient mutant mice. When the ability of sperm to adhere (attach) and bind tothe zona pellicida of cumulus-free eggs was assessed in vitro，没有意义的差异会被观察wild-type and acrosin-deficient mice。免疫分析demonstrated the release of several acrosomal proteins from theacrosome of Acr D2-/- D2 mouse sperm was significantly delayed during the calcium ionophore- andsolubilized zona pellucida-induced acrosome reaction，in spite of normal membrane vesiculation.这些数据显示the delayed sperm penetration of normal membrane vesiculationthe zona pellucida in the acrosin-deficientMore mouse results from the altered rate of protein dispersal from the acrosome，并提供了第一个evidence that the major role of acrosin is to accelerate the dispersal ofacrosomal components during acrosome reaction.2) To identify a novel candidate(s) for acrosomalproteins that act on the sperm/egg interaction，a DNA fragment was PCR-amplified from a cDNA library of acrosin-deficient mouse testis，然后，作为一个例子来描述一个mouse testis cDNA库。each of four similar but different serine proteases, TESP1, TESP2, TESP3, and TESP43) We produced transgenic mouse lines that accumulate mutated green fluorescentprotein (EGFP) in sperm acrosome. The time required for The dispersal of acrosomal components wasdemonstrated to be approximately 3 seconds after the onset of acrosome reaction.4) A porcinehomologue of the major secretory protein of human epididymisHE1 was purified from cauda epididymal fluids. HE1 homologue was found to be a majorcholesterol-binding protein,suggesting that it is involved in the regulation of the lipid composition of the sperm membranesduring sperm maturation in epididymis. Less

To elucidate the sperm function (sperm/egg interaction) in mammalian fertilization, we have carried out biochemical and biological experiments using genetically modified mutant mice, and have obtained the following results :1) To elucidate the role of acrosin in fertilization, we have examined the involvement of acrosin in the acrosome reaction of sperm, using the acrosin-deficient mutant mice. When the ability of sperm to adhere (attach) and bind to the zona pellicida of cumulus-free eggs was assessed in vitro, no significant difference was observed between the wild-type and acrosin-deficient mice. Immunocytochemical analysis demonstrated that the release of several acrosomal proteins from the acrosome of AcrィイD2-/-ィエD2 mouse sperm was significantly delayed during the calcium ionophore- and solubilized zona pellucida-induced acrosome reaction, in spite of normal membrane vesiculation. These data indicate that the delayed sperm penetration of the zona pellucida in the acrosin-deficient … More mouse results from the altered rate of protein dispersal from the acrosome, and provide the first evidence that the major role of acrosin is to accelerate the dispersal of acrosomal components during acrosome reaction.2) To identify a novel candidate(s) for acrosomal proteins that act on the sperm/egg interaction, a DNA fragment was PCR-amplified from a cDNA library of acrosin-deficient mouse testis, and then used as a probe to screen a mouse testis cDNA library. Complementary DNA clones encoding each of four similar but different serine proteases, TESP1, TESP2, TESP3, and TESP4, have been identified.3) We produced transgenic mouse lines that accumulate mutated green fluorescent protein (EGFP) in sperm acrosome. The time required for the dispersal of acrosomal components was demonstrated to be approximately 3 seconds after the onset of acrosome reaction.4) A porcine homologue of the major secretory protein of human epididymis, HE1 was purified from cauda epididymal fluids. The HE1 homologue was found to be a major cholesterol-binding protein, suggesting that it is involved in the regulation of the lipid composition of the sperm membranes during sperm maturation in epididymis. Less