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Danne, N.

Publications and source records attributed to Danne, N..

2 recordsLinked to original sources

Differentiated dynamic response in C. elegans chemosensory cilia

Cilia are membrane-enveloped organelles that protrude from the surface of most eurokaryotic cells and play crucial roles in sensing the external environment. For maintenance and function cilia are dependent on intraflagellar transport (IFT). Here we use a combination of microfluidics and fluorescence microscopy to study the response of phasmid chemosensory neurons, in live Caenorhabditis elegans, to chemical stimuli. We found that chemical stimulation resulted in unexpected changes in IFT and ciliary structure. Notably, stimulation with hyperosmotic solutions or chemical repellents resulted in different responses, not only in IFT, ciliary structure and cargo distribution, but also in neuronal activity. The response to chemical repellents results in habituation of the neuronal activity, suggesting that IFT plays a role in regulating the chemosensory response. Our findings show that cilia are able to sense and respond to different external cues in distinct ways, highlighting the flexible nature of cilia as sensing hubs.

biophysics↗

TRPV channel OCR-2 is distributed along C. elegans chemosensory cilia by diffusion in a local interplay with intraflagellar transport

Sensing and reacting to the environment is essential for survival and procreation of most organisms. Caenorhabditis elegans senses soluble chemicals with transmembrane proteins (TPs) in the cilia of its chemosensory neurons. Development, maintenance and function of these cilia relies on intraflagellar transport (IFT), in which motor proteins transport cargo, including sensory TPs, back and forth along the ciliary axoneme. Here we use live fluorescence imaging to show that IFT machinery and the sensory TP OCR-2 reversibly redistribute along the cilium after exposure to repellant chemicals. To elucidate the underlying mechanisms, we performed single-molecule tracking experiments and found that OCR-2 distribution depends on an intricate interplay between IFT-driven transport, normal diffusion and subdiffusion that depends on the specific location in the cilium. These insights in the role of IFT on the dynamics of cellular signal transduction contribute to a deeper understanding of the regulation of sensory TPs and chemosensing.

biophysics↗