Parthenogenetic activation of porcine oocytes with guanosine-5'-O-(3'-thiotriphosphate).
A possible mechanism by which sperm activate oocytes may involve a G protein-mediated signal-transducing pathway. Artificial stimulation of G proteins leads to events very similar to those at fertilization in oocytes of several species. Here we report the effects of activation of a G protein with guanosine-5'-O-(3'-thiotriphosphate) (GTP-gamma-S), a hydrolysis-resistant analog of guanosine triphosphate (GTP), in porcine oocytes. Mature oocytes were injected with 1 mM GTP-gamma-S. In response to injection, oocytes underwent changes normally occurring at fertilization, i.e. cortical granule exocytosis, changes in the protein synthetic profile, pronuclear formation, and development to the blastocyst stage. Guanosine-5'-O-(2-thiodiphosphate) (GDP-beta-S; a metabolically stable analog of guanosine diphosphate [GDP] that inactivates the G protein) and the carrier medium (CM; medium in which the injected compounds were dissolved) were significantly less effective in oocyte activation. It is suggested that porcine oocytes contain the components of a G protein-mediated signaling pathway that might function in oocyte activation at fertilization.
Macháty
Z
Z
Department of Animal Sciences, University of Missouri-Columbia 65211, USA.
Mayes
M A
MA
Prather
R S
RS
D000818:Animals; D001755:Blastocyst / Q000502:physiology; D005089:Exocytosis; D005260:Female; D019204:GTP-Binding Proteins / Q000502:physiology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology*; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D007399:Interphase; D008854:Microscopy, Electron; D009028:Morula / Q000502:physiology; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D010312:Parthenogenesis; D014176:Protein Biosynthesis; D015398:Signal Transduction; D013552:Swine / Q000502:physiology*; D013873:Thionucleotides / Q000494:pharmacology
D013873:Thionucleotides; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C023427:guanosine 5'-O-(2-thiodiphosphate); D019204:GTP-Binding Proteins