Acrosome Reaction in Sperm of the Frog, Xenopus laevis: Its Detection and Induction by Oviductal Pars Recta Secretion

摘要: Previous electron microscopic observations have shown that the acrosome of sperm frog, Xenopus laevis, comprises a membrane-bounded vesicle covering anterior-most position head. We obtained suspension from testes and stained it with LysoSensor Green for observation under confocal laser scanning microscope found bright fluorescence reflecting presence acrosomes at top head in about 64% sperm, no deterioration their capacity to fertilize. About 40% an underwent reaction response Ca(2+) ionophore A23187, as evidenced by loss stainability, accompanied breakdown acrosomal vesicle. 53% bound isolated vitelline envelopes reaction, whereas both jelly water solubilized weakly induced reaction. When were treated oviductal extract pars recta, but not convoluta region, The substance containing reaction-inducing activity recta seemed be heat-unstable molecular weight greater than 10 kDa. was inhibited protease inhibitors required extracellular ions. These results indicate occurs on deposited during passage oocytes through oviduct.