Fig. 5

Sox3 expression is inhibited by MO injection. (A) Sequence of sox3 5′UTR with MO binding sites labelled. Start codon indicated in bold and the positions of control MO mis-matches are indicated by asterisks. (B) Sections taken from the head of 24 hpf embryos and stained with anti-Sox3 and DAPI. A profound reduction of Sox3 protein expression is seen in embryos co-injected with sox3MO1/2 as compared to wild-type controls. (C) Co-injection of sox3MO1/2 blocked translation of a co-injected sox3-GFP fusion containing the MO target sequence as assayed by GFP fluorescence examined at 50% epiboly but had no effect on GFP alone. (D) Extent of knock-down of GFP fusions assayed by Western blot to detect the GFP protein. Actin was used as a loading control for the Western blot. Injection of sox3MO1 or sox3MO2 individually can be seen to knock-down sox3 translation less effectively than when used in combination. Control MOs (sox3mmMO1/2) could not block translation of sox3-GFP.