Effect of bovine seminal ribonuclease and bovine pancreatic ribonuclease A on bovine oocyte maturation.
Bovine seminal ribonuclease (BS-RNase) contains the MxM (noncovalent dimer) and M=M (free monomer) in constant ratio. The aim of this work was to evaluate the effect of BS-RNase, its monomer and dimer forms, and also various mutants of this enzyme on meiotic completion in cattle oocytes. It was found that BS-RNase has irreversible effects on the meiotic maturation of bovine oocytes in vitro, particularly on the completion of meiosis. The effect of BS-RNase is dose-dependent. In medium supplemented with 1 microg/ml, the results were comparable with those of the control (70% MII oocytes after 24 hr of culture). Whereas 5 microg/ml reduced the number of MII oocytes to 50%, 10 and 25 microg/ml arrested this process completely. The MxM form and RNase A at 5 microg/ml inhibited the maturation rate by 71 and 48%, respectively, but a less significant effect was observed for the M=M form, or the carboxymethylated monomers MCM31 and MCM32 (21%, 16%, and 42% MII oocytes, respectively, in comparison with control). These data demonstrate that bovine ribonucleases can have variable detrimental effects on the maturation of bovine oocyte. J. Exp. Zool. 287:394-399, 2000.
Slavík
T
T
Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Czech Republic. slavik@iapg.cas.cz
Matousek
J
J
Fulka
J
J
Raines
R T
RT
D000818:Animals; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D008540:Meiosis; D009865:Oocytes / Q000166:cytology* / Q000502:physiology; D012260:Ribonucleases / Q000378:metabolism*; D012661:Semen / Q000201:enzymology*
D012260:Ribonucleases