Glycosaminoglycans in the basal lamina and extracellular matrix of the developing mouse mammary duct

When meiotic maturation of primary oocytes of the starfish Asterias forbesi is induced by 1-methyladenine, rapid and striking changes in the pattern of protein synthesis detectable by electrophoresis occur after germinal vesicle breakdown. These include a decline in relative labeling with ³⁵S]methionine of several polypeptides synthesized in the oocyte, and increased labeling and new appearance of several polypeptides. Fertilization does not result in other detectable changes. The population of total mRNA translatable in a rabbit reticulocyte lysate cell-free system does not change, but the distribution of mRNAs between polysomes and the postribosomal supernatant reflects the changes observed in vivo. Thus these changes are regulated at the translational level. A review of the literature indicates that translationally mediated changes in patterns of protein synthesis during maturation of oocytes may be a widespread phenomenon.