Fig. 5.

Posterior teashirt expression is dependent on Wnt signaling. (A) Posterior teashirt expression was reduced by 4 days after RNAi of β-catenin-1, whereas brain expression persisted (n=12/15). This occurred before loss of posterior cell types, indicated by in situ hybridization for fibrillin (n=10/10) and mag-1 (n=12/12). Anterior-restricted sFRP-1 expression was not altered, indicating that major polarity defects have not yet occurred (n=7/7). (B) qRT-PCR analysis of position control gene (PCG) transcriptional changes following β-catenin-1 or APC RNAi in intact uninjured animals. RNA was harvested from uninjured animals after 10 days of RNAi. Biological triplicates consisted of four individual animals each. teashirt transcriptional changes were measured by four independent primer sets (I-IV). Error bars indicate s.d. Individual replicates are indicated by dots. Asterisks indicate significance determined by t-tests between sets of biological triplicate delta-Ct values (*P<0.05) and with standard Bonferroni adjustment (**P<0.0031). (C) teashirt was expressed in both anterior and posterior brains of head fragments subjected to β-catenin-1 RNAi (n=8/9). (A,C) Anterior is leftwards. Scale bars: 200 µm.