title: Microelectrophoretic analysis of changes in protein expression patterns in mouse oocytes and preimplantation embryos.
abstract: One- and two-dimensional polyacrylamide microslab gel electrophoresis followed by silver staining was devised to visualize picogram to nanogram levels of proteins and was applied to the analysis of 1-20 mouse oocytes and embryos (approximately 16.5-330 ng of protein) during preimplantation development. Compared with values in embryos, more bands in the higher molecular weight range were found only for unfertilized oocytes in one-dimensional microelectrophoresis. A marked decrease in the number of protein spots occurred after fertilization in two-dimensional microelectrophoresis. Both findings indicate a decrease in maternal proteins caused by fertilization. Silver-staining densities were almost invariable for 8 major spots, but increased, decreased, or varied for 32 minor spots in developing embryos from the 1-cell to the morula stage, signifying spot-specific changes in the expression of zygotic proteins during development. The protein patterns in cumulus cells and blastocysts were different from those in oocytes and embryos. Even in a single 1-cell embryo, major spots and some minor spots were detectable by our two-dimensional microelectrophoretic technique, but many more minor spots were visualized in five 1-cell embryos, exemplifying the limit of our microelectrophoretic technique. As a preliminary result, a two-dimensional immunoblot pattern is shown for glucose transporter 1 expressed in morulae.
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000737:chemistry; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D004622:Embryo, Mammalian / Q000737:chemistry*; D047108:Embryonic Development; D004910:Erythrocyte Membrane / Q000737:chemistry; D005260:Female; D051272:Glucose Transporter Type 1; D006801:Humans; D015151:Immunoblotting; D008297:Male; D051379:Mice; D009004:Monosaccharide Transport Proteins / Q000032:analysis; D009028:Morula / Q000737:chemistry; D009865:Oocytes / Q000737:chemistry*; D011247:Pregnancy; D011506:Proteins / Q000032:analysis*; D016622:Silver Staining