Effects of ubiquitin-proteasome pathway on mouse sperm capacitation, acrosome reaction and in vitro fertilization

Chlortetracycline (CTC) fluorescence patterns were used to study changes in the patterns B and AR of mouse sperm after incubation with reagents that would block the UPP. They were the monoclonal antibody against ubiquitinated proteins—UCP1; the polyclonal antibody against ubiquitin—anti-Ub, and a special inhibitor against proteasome—ALLN. Furthermore, we treated the capacitated sperm or the eggs with these reagents separately and tested whether the normal in vitro fertilization was blocked or not. Results illustrate that UCP1, anti-Ub, and ALLN have little effects on sperm capacitation and acrosome reaction, but they do inhibit fusion of mouse sperm with eggs, which suggests that UPP play an important role in mouse in vitro fertilization.