Signed, sealed, undelivered: Mechanisms underlying polycystic kidney disease

Zebrafish help investigators shed light on the mechanisms underlying cilia dysfunction in polycystic kidney disease and other ciliopathies. Cilia, the finger-like protrusions on most epithelial cells, were not so long ago thought to be as irrelevant to cell biology as the appendix is to physiology, a vestigial remnant of a long ago evolutionary past. Today, they are recognized as essential chemo-mechanical sensors that monitor and regulate what crosses into and out of a cell.