Fig. 4. Functional consequences of syntenin knockdown. (A) Western blot of keratinocytes transduced with empty vector (ev) or syntenin siRNA (Rnai1) probed with anti-syntenin (a-syn) or, as a loading control, anti-tubulin (a-tub). (B) Hes1 luciferase reporter activity in J2-3T3 cells transduced with empty vector (ev) or the Delta constructs shown, in the presence or absence of syntenin siRNA. Fold induction relative to Renilla control is shown. Mean ± s.e.m. of three experiments. Values significantly different from ev control or Fl are marked with asterisks (Student's t-test: ^***P<0.001 or ^**P<0.05). (C) Clonal growth of keratinocytes transduced with DeltaFl or Delta DS and control (Ctrl) or syntenin Rnai1. (D-G) GFP-labelled clones formed by human keratinocytes expressing DeltaFl alone (Fl; D) or in combination with syntenin Rnai1(E), or formed by mouse keratinocytes with endogenous Delta1 levels (Dll1^flox/flox; F) or lacking Delta1 (K5Cre x Dll1^flox/flox; G). Clones were photographed 5 days after seeding within a confluent sheet of unlabelled WT keratinocytes (human or mouse). Bars, 100 µm. (H) Percentage of cohesive colonies formed by GFP-labelled keratinocytes. Data are mean ± s.d. of three experiments (Student's t-test, ^***P<0.001 compared with % clones in WT).