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Bitter taste receptors confer diverse functions to neurons.

Delventhal R, Carlson JR - Elife (2016)

Bottom Line: Expression of individual Grs conferred strikingly different effects in different neurons.The results support a model in which bitter Grs interact, exhibiting competition, inhibition, or activation.The results have broad implications for the problem of how taste systems evolve to detect new environmental dangers.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, United States.

ABSTRACT
Bitter compounds elicit an aversive response. In Drosophila, bitter-sensitive taste neurons coexpress many members of the Gr family of taste receptors. However, the molecular logic of bitter signaling is unknown. We used an in vivo expression approach to analyze the logic of bitter taste signaling. Ectopic or overexpression of bitter Grs increased endogenous responses or conferred novel responses. Surprisingly, expression of Grs also suppressed many endogenous bitter responses. Conversely, deletion of an endogenous Gr led to novel responses. Expression of individual Grs conferred strikingly different effects in different neurons. The results support a model in which bitter Grs interact, exhibiting competition, inhibition, or activation. The results have broad implications for the problem of how taste systems evolve to detect new environmental dangers.

No MeSH data available.


Related in: MedlinePlus

Electrophysiological response profiles of wCS control S-a sensilla and ΔGr59c S-a sensilla.Response to DEN is reduced in ΔGr59c mutant S-a sensilla (p ≤ 0.0001, n ≥ 12).DOI:http://dx.doi.org/10.7554/eLife.11181.013
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fig7s2: Electrophysiological response profiles of wCS control S-a sensilla and ΔGr59c S-a sensilla.Response to DEN is reduced in ΔGr59c mutant S-a sensilla (p ≤ 0.0001, n ≥ 12).DOI:http://dx.doi.org/10.7554/eLife.11181.013

Mentions: We asked whether △Gr59c has a similar effect on the S-a bitter neuron, which also expresses Gr59c. We found no effect, other than a decrease in the response to DEN (Figure 7—figure supplement 2, p<0.0001, n≥12). The lack of a strong mutant phenotype may reflect the much greater molecular complexity of S-a: apart from the CERs, the S-a bitter neuron expresses 24 Grs, whereas its I-a counterpart expresses only Gr59c. The difference between the △Gr59c phenotype in the two sensilla provides a further example of how the function of a bitter Gr may differ in different neuronal contexts.


Bitter taste receptors confer diverse functions to neurons.

Delventhal R, Carlson JR - Elife (2016)

Electrophysiological response profiles of wCS control S-a sensilla and ΔGr59c S-a sensilla.Response to DEN is reduced in ΔGr59c mutant S-a sensilla (p ≤ 0.0001, n ≥ 12).DOI:http://dx.doi.org/10.7554/eLife.11181.013
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4764594&req=5

fig7s2: Electrophysiological response profiles of wCS control S-a sensilla and ΔGr59c S-a sensilla.Response to DEN is reduced in ΔGr59c mutant S-a sensilla (p ≤ 0.0001, n ≥ 12).DOI:http://dx.doi.org/10.7554/eLife.11181.013
Mentions: We asked whether △Gr59c has a similar effect on the S-a bitter neuron, which also expresses Gr59c. We found no effect, other than a decrease in the response to DEN (Figure 7—figure supplement 2, p<0.0001, n≥12). The lack of a strong mutant phenotype may reflect the much greater molecular complexity of S-a: apart from the CERs, the S-a bitter neuron expresses 24 Grs, whereas its I-a counterpart expresses only Gr59c. The difference between the △Gr59c phenotype in the two sensilla provides a further example of how the function of a bitter Gr may differ in different neuronal contexts.

Bottom Line: Expression of individual Grs conferred strikingly different effects in different neurons.The results support a model in which bitter Grs interact, exhibiting competition, inhibition, or activation.The results have broad implications for the problem of how taste systems evolve to detect new environmental dangers.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, United States.

ABSTRACT
Bitter compounds elicit an aversive response. In Drosophila, bitter-sensitive taste neurons coexpress many members of the Gr family of taste receptors. However, the molecular logic of bitter signaling is unknown. We used an in vivo expression approach to analyze the logic of bitter taste signaling. Ectopic or overexpression of bitter Grs increased endogenous responses or conferred novel responses. Surprisingly, expression of Grs also suppressed many endogenous bitter responses. Conversely, deletion of an endogenous Gr led to novel responses. Expression of individual Grs conferred strikingly different effects in different neurons. The results support a model in which bitter Grs interact, exhibiting competition, inhibition, or activation. The results have broad implications for the problem of how taste systems evolve to detect new environmental dangers.

No MeSH data available.


Related in: MedlinePlus