I've officially heard my favorite one-liner here at the Keystone symposium on the molecular basis for biological membrane organization. In her presentation on the molecular link between polycystic defects such as retinopathies and polycystic kidney disease, Angela Wandinger-Ness of the University of New Mexico offered this gem: "There is a connection between seeing and peeing."

After the giggles subsided, Wandinger-Ness went on to describe her research on the commonality of primary cilia malfunction in such diseases. She said that problems with the localization of signaling proteins to the ciliary membranes and the subsequently disrupted membrane trafficking may be the key to problems with kidney function, vision, and other sensory pathways.

In vision, for example, mutations in the ciliary protein rhodopsin - which functions in initiating light sensing and photoreceptor formation - may lead to developmental disorders resulting in cell death and degeneration of the retina. Mutations in polycystic kidney disease genes, such as PKD1, prevent localization of their corresponding membrane proteins - which normally sense urine flow in urinary collecting ducts and serve as calcium channels - to cilia in the kidney and disrupt normal kidney development and function. She also identified a common amino acid motif that seems essential to the normal localization and function of ciliary proteins in everything from olfaction to retinal function. "The primary cilium is the unifying link," she said.