Microelectrophoretic Analysis of Changes in Protein Expression Patterns in Mouse Oocytes and Preimplantation Embryos1

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.

Quantification of transforming growth factor beta1 (TGFbeta1) mRNA expression in mouse preimplantation embryos and determination of TGFbeta receptor (type I and type II) expression in mouse embryos and reproductive tract

“…In the present study, Tβ RII protein persisted but dropped gradually from the 1-cell to the blastocyst stage. In connection with this, it has been reported that a number of major and minor proteins persist in preimplantation embryos at all stages of development (Sasaki et al, 1999). Some of these proteins have an expression profile similar to the protein expression pattern of Tβ RII reported here.…”

Endometrial tumor necrosis factor α (TNFα) is a likely mediator of early luteal phase mifepristone-mediated negative effector action on the preimplantation embryo

“…Morula-to-blastocyst transition is a critical step in the process of embryogenesis characterized by ultrastructural polarization (Enders et al 1990, Ducibella et al 1995, Ohsugi et al 1999 and specific profiles of proteins synthesized at this developmental stage (Zheng et al 1993, Shi et al 1994, Sasaki et al 1999. Mouse blastocysts allowed to develop in vivo are classified into four substages based on their ultrastructural features: substage one, when blastoceolic cavity is well formed but not expanded, substage two, when the cavity is expanded but ICM cells do not show any clear-cut differentiation, substage three, when ICM shows differentiation into epiblast and proximal entoderm, and substage four, when visceral entoderm develops and forms a continuous layer around the blastocyst cavity (Nadijcka & Hillman 1974).…”

Identification of developmental competence‐related genes in mature porcine oocytes

“…These cellular events, collectively referred to as cytoplasmic maturation, are required for successful subsequent embryonic development (Eppig, 1996). During oogenesis, oocytes accumulate a larger‐than‐necessary amount of transcripts that are important for oocyte maturation and early embryo development (Sasaki et al, 1999). Transcription and storage of most transcripts occurs during the early stages of oocyte growth.…”