Fig 5. Altered planar cell polarity causes cyst formation.

Correct orientation of the mitotic spindle and centrosomes of renal tubular epithelial cells are especially during development required for proper growth of the longitudinal axis of the tubule (A). If the apical-basolateral polarity is disrupted a dilated tubule or cyst would develop (B). Non-canonical Wnt signaling is involved in proper cell orientation. Urinary flow in the renal tubules could provide signaling via cilia about cellular orientation. Adapted from Germino 2005. ¹¹⁰