RRC ID 45843
Author Russell J, Vidal-Gadea AG, Makay A, Lanam C, Pierce-Shimomura JT.
Title Humidity sensation requires both mechanosensory and thermosensory pathways in Caenorhabditis elegans.
Journal Proc. Natl. Acad. Sci. U.S.A.
Abstract All terrestrial animals must find a proper level of moisture to ensure their health and survival. The cellular-molecular basis for sensing humidity is unknown in most animals, however. We used the model nematode Caenorhabditis elegans to uncover a mechanism for sensing humidity. We found that whereas C. elegans showed no obvious preference for humidity levels under standard culture conditions, worms displayed a strong preference after pairing starvation with different humidity levels, orienting to gradients as shallow as 0.03% relative humidity per millimeter. Cell-specific ablation and rescue experiments demonstrate that orientation to humidity in C. elegans requires the obligatory combination of distinct mechanosensitive and thermosensitive pathways. The mechanosensitive pathway requires a conserved DEG/ENaC/ASIC mechanoreceptor complex in the FLP neuron pair. Because humidity levels influence the hydration of the worm's cuticle, our results suggest that FLP may convey humidity information by reporting the degree that subcuticular dendritic sensory branches of FLP neurons are stretched by hydration. The thermosensitive pathway requires cGMP-gated channels in the AFD neuron pair. Because humidity levels affect evaporative cooling, AFD may convey humidity information by reporting thermal flux. Thus, humidity sensation arises as a metamodality in C. elegans that requires the integration of parallel mechanosensory and thermosensory pathways. This hygrosensation strategy, first proposed by Thunberg more than 100 y ago, may be conserved because the underlying pathways have cellular and molecular equivalents across a wide range of species, including insects and humans.
Volume 111(22)
Pages 8269-74
Published 2014-6-3
DOI 10.1073/pnas.1322512111
PII 1322512111
PMID 24843133
PMC PMC4050571
MeSH Acid Sensing Ion Channels / physiology Animals Behavior, Animal / physiology Caenorhabditis elegans / cytology Caenorhabditis elegans / physiology* Caenorhabditis elegans Proteins / physiology Cyclic GMP / physiology Epithelial Sodium Channels / physiology Humans Humidity* Ion Channel Gating / physiology Ion Channels / physiology Mechanoreceptors / physiology* Membrane Proteins / physiology Motor Activity / physiology Multiprotein Complexes / physiology Sensory Receptor Cells / physiology* Starvation / physiopathology Thermosensing / physiology*
IF 9.504
Times Cited 17
C.elegans tm1552