Et al. eLife 2015;four:e10735. DOI: ten.7554/eLife.eight ofResearch articleNeuroscienceFigure 4. Certain Trimeric G proteins act downstream of DTKR in class IV neurons in thermal allodynia. (A) Schematic of genetic screening strategy for testing G-protein subunit function by in vivo tissue-specific RNAi in class IV neurons. (B) UV-induced thermal allodynia on targeting the indicated G protein subunits by RNAi. n = 30 larvae per genotype. P = 0.082, P0.05. Statistical significance was determined by Fisher’s precise test. (C) UVinduced thermal allodynia for the 3 putative hits from the mini-screen in a. (1) and (two) indicate non-overlapping RNAi transgenes. (D) Suppression of UAS-DTKR-induced “genetic” allodynia by co-expression of UAS-RNAi transgenes targeting the indicated G protein subunits. Seven sets of n=30 for ppkDTKR-GFP controls, triplicate sets of n=30 for the rest. DOI: ten.7554/eLife.10735.013 The following figure supplements are offered for figure four: Figure supplement 1. Alternative data presentation of UV-induced thermal allodynia on targeting G protein subunits by RNAi (Figure 4B) in non-categorical line graphs of accumulated % response as a function of measured latency. DOI: ten.7554/eLife.10735.014 Figure supplement two. UAS alone controls of RNAi targeting G protein subunits usually do not exhibit defects in UVinduced thermal allodynia. DOI: ten.7554/eLife.10735.Im et al. eLife 2015;four:e10735. DOI: 10.7554/eLife.9 ofResearch 616-91-1 Cancer articleNeuroscienceanalyzing our behavioral data categorically, Gb5 was not very significant, but when the data was analyzed non-categorically (accumulated percent response versus latency) the improved statistical energy of this system revealed that Gb5 was substantially different from the control (Figure 4–figure supplement 1). Certainly, retesting the strongest hits in higher numbers and analyzing them categorically revealed that knockdown of a putative Gaq (CG17760), Gb5 (CG10763), and Gg1 (CG8261) all substantially reduced thermal allodynia in comparison with GAL4 and UAS-alone controls (Figure 4C and Figure 4–figure supplements 1 and two). To test if these subunits act downstream of DTKR, we asked irrespective of whether expression of your relevant UAS-RNAi transgenes could also block the ectopic thermal allodynia induced by DTKR-GFP overexpression (Figure 2F). All of them did (Figure 4D). For that reason, we conclude that CG17760, Gb5, and Gg1 will be the downstream G protein subunits that couple to DTKR to 545380-34-5 Protocol mediate thermal allodynia in class IV neurons.Tachykinin signaling acts upstream of Smoothened and Painless in allodyniaThe signal transducer from the Hedgehog (Hh) pathway, Smoothened (smo), is needed inside class IV neurons for UV-induced thermal allodynia (Babcock et al., 2011). To determine if Tachykinin signaling genetically interacts with the Hh pathway for the duration of thermal allodynia, we tested the behavior of a double heterozygous combination of dtkr and smo alleles. Such larvae are defective in UV-induced thermal allodynia when compared with relevant controls (Figure 5A and Figure 5–figure supplement 1). We next performed genetic epistasis tests to establish whether Tachykinin signaling functions upstream, downstream, or parallel of Hh signaling in the course of improvement of thermal allodynia. The basic principle was to co-express an activating transgene of one pathway (which induces genetic thermal allodynia) collectively with an inactivating transgene of the other pathway. Lowered allodynia would indicate that the second pathway was acting downstre.