Qualitative patterns of protein synthesis in the mouse oocyte

Abstract

Mouse oocytes were found to sythesize proteins actively at the germinal vesicle, metaphase I, metaphase II, and pronuclear (6 hours post‐fertilization) stages. The qualitative pattern of protein components being sythesized in vitro, as demonstrated using polyacrylamide gel electrophoresis, changed throughout maturation and fertilization. Oocytes were arrested at metaphase I by ≥ 0.1 μg/ml cycloheximide or actinomycin D. The protein pattern in oocytes cultured in the presence of actinomycin D progresses to a metaphase II pattern in spite of the nuclear maturation arrest, indicating a dissociation between meiotic maturation and the changes in the pattern of proteins synthesized at different stages of maturation.