Localized protein synthesis during oogenesis of Xenopus laevis: analysis by in situ translation

An in situ translation assay was developed to examine localized protein synthesis activity on the subcellular level of fixed and sectioned material by autoradiography. Our data indicate that in situ translation produced polypeptides also synthesized in vivo and is dependent on protein synthesis from messenger RNA preserved in the fixed material. Applied to oocytes of Xenopus laevis at different stages, the in situ translation assay revealed localized protein synthesis activity in the cortical region of vitellogenic and postvitellogenic oocytes. The spatial pattern of protein synthesis activity observed in stage 6 oocytes disappeared when oocytes were induced to mature.