Document Type

Article

Language

eng

Publication Date

2017

Publisher

Nature Publishing Group (Macmillan Publishers Limited)

Source Publication

Scientific Reports

Source ISSN

2045-2322

Original Item ID

DOI: 10.1038/s41598-017-00120-z

Abstract

The biogenic amine tyramine (TA) regulates many aspects of invertebrate physiology and development. Although three TA receptor subtypes have been identified (TAR1-3), specific receptors have not been linked to physiological responses in native tissue. In the Malpighian (renal) tubule of Drosophila melanogaster, TA activates a transepithelial chloride conductance, resulting in diuresis and depolarization of the transepithelial potential. In the current work, mutation or RNAi-mediated knockdown in the stellate cells of the tubule of TAR2 (tyrR, CG7431) resulted in a dramatic reduction, but not elimination, of the TA-mediated depolarization. Mutation or knockdown of TAR3 (tyrRII, CG16766) had no effect. However, deletion of both genes, or knockdown of TAR3 on a TAR2 mutant background, eliminated the TA responses. Thus while TAR2 is responsible for the majority of the TA sensitivity of the tubule, TAR3 also contributes to the response. Knockdown or mutation of TAR2 also eliminated the response of tubules to the related amine octopamine (OA), indicating that OA can activate TAR2. This finding contrasts to reports that heterologously expressed TAR2 is highly selective for TA over OA. This is the first report of TA receptor function in a native tissue and indicates unexpected complexity in the physiology of the Malpighian tubule.

Comments

Published version. Scientific Reports, Vol. 168, No. 7 (2017). DOI. © 2017 The Author(s).

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Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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