(A) Top: Diagram of Ppl protein domains. Amino acid numbers are indicated above. Bottom: Amino acid sequence of IF-binding domains of zebrafish and human Ppl, showing locations of the ∆DWEEI and ∆1/2BOX2 mutations. (B) Images of tagged Ppl(sRT2)-, Ppl(sRT2-∆DWEEI)-, and Ppl(sRT2-∆1/2BOX2)-expressing periderm cells in WT animals. (C) Lifeact-mRuby-expressing periderm cells mosaically expressing GFP-tagged Ppl (left), the Ppl(∆DWEEI) mutant (middle), or the Ppl(∆1/2BOX2) mutant (right) in ppl−/− mutant animals. Neighboring cells lacking GFP serve as controls. (D) Scatter plot of average microridge length versus mean fluorescence intensity in ppl−/− periderm cells expressing full-length Ppl (red line), Ppl(∆DWEEI) (green line), or Ppl(∆1/2BOX2) (blue line). Shading indicates 95% confidence interval. Slopes = 0.0118, 0.0077, and 0.0064; R = 0.74, 0.6, and 0.54, for red, green, and blue lines, respectively. n = 24–51 cells from 3 to 4 fish per category. Scale bars: 10 µm.