Fig. 3

uhrf1 knockdown does not phenocopy UHRF1 overexpression. (A) Developmental progression of uninjected embryos and uhrf1 morphants (MO2-5′-UTR) at each indicated stage. At high stage (~3.3 hpf) both uninjected embryos and uhrf1 morphants appear normal and at 50% Epiboly (~5.25 hpf), arrow indicates arrest of uhrf1 morphants that have progressed to yolk extrusion. At shield stage (~6.0 hpf), arrow indicates significant developmental delay in uhrf1 morphants that did not arrest at high stage. Morphants that did arrest at high stage are dead by the time uninjected embryos have reached shield stage. At bud stage (~10.0 hpf), arrow indicates tail bud formation prior to the completion of epiboly in uhrf1 morphants. At 7-8 Somite stage (~12.0 hpf), arrows indicate disrupted CNS, somites and tail bud. At Prim 5 stage (~24.0 hpf), arrows indicate that all surviving uhrf1 morphants display CNS and tail defects. Scale bar=500 µm. (B) Embryos were scored at 6 hpf for asymmetric epiboly, high stage arrest or delay. The depletion of endogenous Uhrf1 by injection of 13 ng 5′UTR uhrf1 morpholino does not affect the asymmetric epiboly phenotype caused by injection of 100 pg of WT-UHRF1 or UHRF1^S661A mRNA. The co-injection of WT-UHRF1 or UHRF1^S661A mRNA additively increases the percentage of the embryos affected by the asymmetric epiboly phenotype. The treatments, the number of biological replicates, number of embryos and the proportion of embryos displaying the asymmetric epiboly phenotype are indicated.