Fig. 6
Notch-mediated DeltaD endocytosis results in DeltaD degradation. (A-B′) Distribution of DeltaD-HA in WT and Notch MO zebrafish embryos. In vitro synthesized mRNA encoding DeltaD-HA and MycPM was co-injected with control (WT in A,A′) or notch1a and notch3 MOs (Notch MO in B,B′). Embryos are labeled with anti-HA mAb (green) and anti-myc pAb (red) at 80% epiboly stage. More DeltaD-HA is localized in cytoplasmic puncta in WT than in Notch MO cells. (C-H′) Comparison of DeltaD-HA (green) and MycPM stability with (F-H) and without Notch morpholinos (C-E). DeltaD-HA expression reduces from 80% epiboly (C) to the two-somite stage (2 ss) (D) and is barely detectable at the five-somite stage (5 ss) (E) in WT. By comparison, MycPM expression levels are progressively increased from 80% epiboly to 5 ss (C′-E′). In Notch MO embryos, Delta-HA (F-H) behaves like MycPM (F′-H′) and its expression is not decreased. |