Cellular "antennae" guide developments

The threadlike cilia that propel microorganisms through liquid are also found on many human cells, such as those that transport human ova in the Fallopian tubes. Unmoving, or “primary,” cilia also appear on human cells, but their function is largely unknown.

A research team that included Joshua J. Breunig, Ph.D., and Matthew R. Sarkisian, Ph.D., postdoctoral associates in the laboratory of Pasko Rakic, M.D., Ph.D., chair and Dorys McConnell Duberg Professor of Neurobiology, suggests that some primary cilia act as “antennae” for signals from a key developmental protein known as sonic hedgehog (Shh).

In the September 2 issue of Proceedings of the National Academy of Science, the group reports that deleting genes needed to form primary cilia in mice caused brain abnormalities, and Shh could not signal neural stem cells to create new neurons.

Since Shh has also been implicated in brain tumor formation, the findings may shed light on cancer as well as development.