In mammals, proteases are present in sperm acrosome and play key role in fertilization. Sturgeon sperm has an acrosome, but its physiology, biochemistry, and potential role in fertilization are unknown. In the present study, we have observed high protease activity in acidic extract of intact sperm compared to that of seminal plasma in sterlet (Acipenser ruthenus). The protease activity was decreased and increased in acidic extract of motility-activated sperm and in the activation medium, respectively. Molecular analysis revealed total protease and serine (acrosin) protease activities in sperm acidic extract which was accumulated in a protein band with relative molecular mass of 35 kDa. Immunoelectron microscopy using an affinity-purified polyclonal antibody for boar acrosin localized the protease at the acrosome region. Moreover, initiation of sperm motility was inhibited after activation in the presence of inhibitors for both trypsin-like and chymotrypsin-like proteases, while the effects of protease inhibitors on sperm velocity were uncertain. Our results indicate similarities in physiology and biochemistry of acrosome between sturgeon and mammals and suggest potential role of protease in the initiation of sperm motility in sturgeon.

• MeSH
• Acrosin metabolism   MeSH
• Acrosome enzymology   MeSH
• Analysis of Variance MeSH
• Histological Techniques veterinary   MeSH
• Microscopy, Immunoelectron veterinary   MeSH
• Protease Inhibitors pharmacology   MeSH
• Sperm Motility drug effects   physiology   MeSH
• Statistics, Nonparametric MeSH
• Peptide Hydrolases pharmacology   MeSH
• Rosaniline Dyes MeSH
• Fishes physiology   MeSH
• Semen enzymology   MeSH
• Spermatozoa drug effects   enzymology   physiology   MeSH
• Tosylphenylalanyl Chloromethyl Ketone pharmacology   MeSH
• Tosyllysine Chloromethyl Ketone pharmacology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Acrosin MeSH
• coomassie Brilliant Blue MeSH Browser
• Protease Inhibitors MeSH
• Peptide Hydrolases MeSH
• Rosaniline Dyes MeSH
• Tosylphenylalanyl Chloromethyl Ketone MeSH
• Tosyllysine Chloromethyl Ketone MeSH