|
Fig. 7
prdm1aDBD-VP16 and prdm1aDBD-EnR together rescue NCCs in prdm1a mutant embryos. (A-E) Lateral views of WT and prdm1a-/- zebrafish embryos at 24 hpf, dorsal to the top. ISH for crestin expression in WT and/or heterozygotes reveals migrating NCCs in the trunk (A). prdm1a mutant embryos have little NCC migration and most do not exhibit migration in more than seven somites (B). Injection of prdm1aDBD-VP16 (C) or prdm1aDBD-EnR (D) alone cannot rescue NCCs in prdm1a mutants. However, injection of prdm1aDBD-VP16 and prdm1aDBD-EnR together rescues crestin expression in prdm1a-/- embryos and NCCs of rescued animals are able to migrate similarly to WT (compare E with A), suggesting that Prdm1a must function as both a transcriptional activator and repressor for migratory NCCs to develop. prdm1a-/- embryos were identified by their curved tail, U-shaped somites and fin mesenchyme defects, and confirmed by genotyping. (F) The percentage of embryos with NCCs present in seven or more somites. Sample size: Prdm1a mutants alone (with NCCs in seven or more somites), n=7/106; Prdm1a mutants injected with Vp16, n=2/55; Prdm1a mutants injected with EnR, n=2/29; Prdm1a mutants injected with both prdm1a-DBD-Vp16 and EnR, n=52/125.