Fig. 4. Increasing apical domain size alters lumen shape.

a Representative images of fixed wildtype (WT, left) and overexpressing Rab11a-GFP (Rab11a-GFP OE, right, purple) MDCK spheroids immunostained for the apical surface protein Podocalyxin (PDX, orange) and DNA (blue). b Lumen solidity plotted as a function of normalized lumen radius for wildtype (WT, purple) and apical expansion manipulations (Rab11a-GFP OE red, Crumbs3a overexpression [OE], orange and KIBRA knockdown [KD], yellow; p-value from two-sided 2D Kolmogorov–Smirnov test). For plot b, n = 51 WT, 3 Crumbs3a OE³⁰, 4 KIBRA KD³¹, and 51 Rab11a-GFP OE conditions. Scale bars are 10 µm. Source data are provided in the Source Data file.