Evolutionarily conserved organelles that are specialized for sensory functions

In the free-living nematode Caenorhabditis elegans, cilia
are found on the dendritic endings of sensory neurons.  C. elegans  cilia are classified as ‘primary’ or ‘sensory’ according to the ‘9+0’ axonemal ultrastructure (nine doublet outer microtubules with no central microtubule pair) and lack of motility, characteristics of ‘9+2’ cilia.  The C. elegans ciliated nervous system allows the animal to perceive environmental stimuli and make appropriate developmental, physiological, and behavioral decisions.  In vertebrates, the biological significance of primary cilia had been largely neglected.  Recent findings have placed primary/sensory cilia in the center of cellular signaling and developmental processes.  Studies using genetic model organisms such as C. elegans identified the link between ciliary dysfunction and human ciliopathies.  Ongoing studies in the Barr lab use “the worm” to address important basic questions regarding ciliary development, morphogenesis, specialization, and signaling functions.  We rely heavily on fluorescence imaging techniques to study ciliary protein localization and dynamics. 

References:

Bae YK, Barr MM.  Sensory roles of neuronal cilia: cilia development, morphogenesis, and function in C. elegans. Front Biosci. 2008 May 1;13:5959-74.  Review.  PMID: 18508635

Jauregui AR, Nguyen KC, Hall DH, Barr MM.  The Caenorhabditis elegans nephrocystins act as global modifiers of cilium structure.  J Cell Biol. 2008 Mar 10;180(5):973-88. PMID: 18316409

Bae YK, Qin H, Knobel KM, Hu J, Rosenbaum JL, Barr MM.  General and cell-type specific mechanisms target TRPP2/PKD-2 to cilia.  Development. 2006 Oct;133(19):3859-70.  PMID: 16943275