Figure 7.

Cells with nuclear p-β-cat-Ser552 initiate crypt fission and budding. (a–c) In PTEN-deficient polyps, a cluster of cells with nuclear p-β-cat-Ser552 was found at the apex of the ridge of dividing crypts in crypt fission (a,b) and at the point of initiation of a budding crypt (c). (d,e) Serial view of a dividing crypt (fission) (d) and a budding crypt (e) in the PTEN mutants, detected using a confocal Z-stack in which cells with nuclear p-β-cat-Ser552 were found at the point of initiation of fission or budding. Cryptdin was used to detect Paneth cells (see Supplementary Videos 1 and 2).