Figure 4. Ybx1 is required for localization and regulated processing of sqt RNA.
(A) Control embryos at 23°C show sqt RNA localization at the 1-cell and 4-cell stage. sqt RNA transport is delayed in 1-cell Mybx1sa42 embryos at 28.5°C, but localizes correctly by the 4-cell stage. At 23°C, sqt RNA largely remains in the yolk even at 4-cell stage and sqt RNA that reaches the blastoderm is mis-localized. Localization of sqt RNA is restored in Mybx1 by ybx1-2a-gfp MTg, but not by PTg. Localization of wnt8a RNA is normal in Mybx1sa42 mutants at 28.5°C and 23°C. Scale bar, 100 μm. (B) Q-RT-PCRs to detect total sqt RNA levels show a mild reduction in Mybx1 compared to controls. Error bars show standard deviation from three experiments. (C) RT-PCR to detect sqt in control and Mybx1 mutants at 1-cell, 4-cell and 16-cell stages. Products are indicated on the right, and sizes on the left. Polyadenylated sqt RNA is detected from 16-cells in controls, and at 1-cell in Mybx1 mutants. Splicing of sqt intron 1 and sqt intron 2 occurs earlier in Mybx1 embryos compared to controls. PCR to detect actin is shown as control.
Figure 4—figure supplement 1. Localization of sqt RNA is affected in Mybx1 embryos, whereas vasa, eomesa, snail1a, grip2 and cyclin B1 are unaffected.
