Fig. 5: Computational modeling of the ICWs in larval and adult flies.

A Simulated global ICWs in the fat body of WT and Inx2-RNAi larvae. The result was repeated in 3 independent simulations. B The simulated concentration of AKH after release from the APC at the head of the larva. The result was repeated in 3 independent simulations. C Quantification of the relative Ca²⁺ intensity in the entire fat body using simulated (Sim) and experimental (Exp) data. The variance in the simulated data originates from the incorporation of random Ca²⁺ fluctuation into the model. N = 3, 3 simulated fat bodies (Sim), N = 6, 6 experimental fat bodies (Exp). D Simulated ICWs in the fat body of WT and Inx2-RNAi adult flies. The result was repeated in 3 independent simulations. E The simulated concentration of AKH with stochastic fluctuation in adult hemolymph. The result was repeated in 3 independent simulations. F Quantification of the relative Ca²⁺ intensity in the entire fat body using simulated (Sim) and experimental (Exp) data. N = 3, 3 simulated fat bodies (Sim), N = 3, 3 experimental fat bodies (Exp). G, H Quantification of the relative amplitude and FWHM (full width at half maximum) of the Ca²⁺ signal in individual fat cells from WT or Inx2-RNAi flies using simulated (Sim) and experimental (Exp) data. Data was pooled from 3 independent simulations and 3 independent experiments. N = 511, 511, 511, 511 oscillations (G), N = 529, 529, 465, 260 oscillations (H). I–J The correlation of Ca²⁺ activities along the wavefront was quantified by dividing the maximum variance of Ca²⁺ intensity by the square of the mean intensity. The relative maximum variations at the head and tail region were compared in both WT and Inx2-RNAi flies. Data was pooled from 4 independent simulations and 4 independent experiments. N = 4, 4, 4, 4 simulated fat bodies (Sim), N = 4, 4, 4, 4 experimental fat bodies (Exp). K A schematic model of the ICWs in larvae and adult flies. The strong exocellular AKH pulse synchronized the global ICWs in a larva, which renders the signal diffusion through the gap junction less important. In contrast, in adult fly, the effective AKH is probably more uniform and triggers gap-junction-dependent random ICWs. Ca²⁺ intensity (arbitrary units) was presented using a linear colour scale (minimum = 0, maximum = 255) (A, D), and AKH concentration (μM) was presented using a linear colour scale (minimum = 0, maximum = 100) (B) and a linear colour scale (minimum = 0, maximum = 30) (E). Unpaired two-tailed Student’s t-test was used in (C, F, G, H, J). Data were plotted as mean ± SD. Scale bars, 500 μm. Source data are provided as a Source Data file.