The sense of water in the blowfly Protophormia terraenovae.
The gustatory system of the blowfly, Protophormia terraenovae, is a relatively simple biological model for studies on chemosensory input and behavioral output. It appears to have renewed interest as a model for studies on the role of water channels, namely aquaporins or aquaglyceroporins, in water detection. To this end, we investigated the presence of water channels, their role in "water" and "salt" cell responsiveness and the transduction mechanism involved. For the first time our electrophysiological results point to the presence of an aquaglyceroporin in the chemoreceptor membrane of the "water" cell in the blowfly taste chemosensilla whose transduction mechanism ultimately involves an intracellular calcium increase and consequently cell depolarization. This hypothesis is also supported by calcium imaging data following proper stimulation. This mechanism is triggered by "water" cell stimulation with hypotonic solutions and/or solutes such as glycerol which crosses the membrane by way of aquaglyceroporins. Behavioral output indicates that the "sense" of water in blowflies is definitely not dependent on the "water" cell only, but also on the "salt" cell sensitivity. These findings also hypothesize a new role for aquaglyceroporin in spiking cell excitability.
Solari
Paolo
P
Department of Experimental Biology, University of Cagliari, Cittadella Universitaria di Monserrato, Monserrato (CA), Italy.
Masala
Carla
C
Falchi
Angela Maria
AM
Sollai
Giorgia
G
Liscia
Anna
A
D000818:Animals; D051397:Aquaglyceroporins / Q000037:antagonists & inhibitors / Q000502:physiology; D002628:Chemoreceptor Cells / Q000502:physiology* / Q000648:ultrastructure; D019327:Copper Sulfate / Q000494:pharmacology; D004175:Diptera / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D055724:Electrophysiological Phenomena / Q000502:physiology; D005632:Fructose / Q000494:pharmacology; D005682:Gadolinium / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D008857:Microscopy, Interference; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology; D013649:Taste / Q000502:physiology*; D014867:Water / Q000502:physiology*
D051397:Aquaglyceroporins; D014867:Water; D005632:Fructose; D012965:Sodium Chloride; D005682:Gadolinium; D019327:Copper Sulfate; C038958:gadolinium chloride; D005990:Glycerol