Cilia and flagella are highly conserved organelles that have diverse roles in eukaryotic cells. The recent discovery that several diseases (collectively known as ciliopathies) are caused by defects in the structure, function and/or associated signalling pathways of these organelles has led to renewed interest in their biology. This issue's Minifocus includes a collection of articles that review several important topics in this area. Peter Satir and colleagues provide an overview of the primary cilium in a Cell Science at a Glance poster article (p. ), and Scott Seely and Maxence Nachury review the mechanisms by which the primary cilium is assembled and disassembled (p. ). Sensory functions were previously attributed mainly to nonmotile primary cilia rather than to motile cilia; however, as discussed by Robert Bloodgood in an Opinion article (p. ), sensory functions for motile cilia have in fact been documented throughout the past century. More recently, the mechanics that enable beating of motile cilia and flagella have been uncovered and, on page , Charles Lindemann and Kathleen Lesich consider this new evidence and discuss how axonemal dynein coordination might operate. Finally, David Engman and colleagues shed light on the mechanisms by which proteins and lipids are transported to ciliary membranes (p. ).
