TY - JOUR
T1 - Gustatory receptors required for avoiding the insecticide L-canavanine
AU - Lee, Youngseok
AU - Kang, Min Jung
AU - Shim, Jaewon
AU - Cheong, Chae Uk
AU - Moon, Seok Jun
AU - Montell, Craig
PY - 2012/1/25
Y1 - 2012/1/25
N2 - Insect survival depends on contact chemosensation to sense and avoid consuming plant-derived insecticides, such as L-canavanine. Members of a family of ~60 gustatory receptors (GRs) comprise the main peripheral receptors responsible for taste sensation in Drosophila. However, the roles of most Drosophila GRs are unknown. In addition to GRs, a G protein-coupled receptor, DmXR, has been reported to be required for detecting L-canavanine. Here, we showed that GRs are essential for responding to L-canavanine and that flies missing DmXR displayed normal L-canavanine avoidance and L-canavanine-evoked action potentials. Mutations disrupting either Gr8a or Gr66a resulted in an inability to detect L-canavanine.Wefound that L-canavanine stimulated action potentials in S-type sensilla, which were where Gr8a and Gr66a were both expressed, but not in Gr66a-expressing sensilla that did not express Gr8a. L-canavanine-induced action potentials were also abolished in the Gr8a and Gr66a mutant animals. Gr8a was narrowly required for responding to L-canavanine, in contrast to Gr66a, which was broadly required for responding to other noxious tastants. Our data suggest that GR8a and GR66a are subunits of an L-canavanine receptor and that GR8a contributes to the specificity for L-canavanine.
AB - Insect survival depends on contact chemosensation to sense and avoid consuming plant-derived insecticides, such as L-canavanine. Members of a family of ~60 gustatory receptors (GRs) comprise the main peripheral receptors responsible for taste sensation in Drosophila. However, the roles of most Drosophila GRs are unknown. In addition to GRs, a G protein-coupled receptor, DmXR, has been reported to be required for detecting L-canavanine. Here, we showed that GRs are essential for responding to L-canavanine and that flies missing DmXR displayed normal L-canavanine avoidance and L-canavanine-evoked action potentials. Mutations disrupting either Gr8a or Gr66a resulted in an inability to detect L-canavanine.Wefound that L-canavanine stimulated action potentials in S-type sensilla, which were where Gr8a and Gr66a were both expressed, but not in Gr66a-expressing sensilla that did not express Gr8a. L-canavanine-induced action potentials were also abolished in the Gr8a and Gr66a mutant animals. Gr8a was narrowly required for responding to L-canavanine, in contrast to Gr66a, which was broadly required for responding to other noxious tastants. Our data suggest that GR8a and GR66a are subunits of an L-canavanine receptor and that GR8a contributes to the specificity for L-canavanine.
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U2 - 10.1523/JNEUROSCI.4630-11.2012
DO - 10.1523/JNEUROSCI.4630-11.2012
M3 - Article
C2 - 22279227
AN - SCOPUS:84863074578
SN - 0270-6474
VL - 32
SP - 1429
EP - 1435
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 4
ER -