FIG. 1.

Time course of RNA-protein interactions during vegetal RNA localization in Xenopus oocytes. (A to C) Alexa Fluor 546-labeled VLE RNA transcripts were injected into the nuclei of stage III Xenopus oocytes. Oocytes were fixed at the indicated time points postinjection (4 h [A], 16 h [B], and 4 days [C]) and viewed by confocal microscopy. The injected RNA (red) is evident in the nucleus in panel A, is asymmetrically distributed within the vegetal hemisphere cytoplasm in panel B, and is restricted to the vegetal cortex in panel C. The vegetal hemisphere is oriented toward the bottom (A to C), and the scale bars are 100 μm. (D) Radiolabeled VLE RNA transcripts were injected into the nuclei of stage III Xenopus oocytes. Oocyte lysates were prepared at either 1 h (lane 1) or 16 h (lane 2) postinjection and cross-linked by UV irradiation. After RNase treatment, labeled proteins were resolved by SDS-PAGE and visualized by autoradiography. The position of Vg1RBP/vera is indicated at the right, and molecular mass standards are on the left.