Figure 1. A dilution mechanism cannot explain growth control in the Drosophila wing disc.

(A) Drosophila wing disc area growth as reported in ref. 17 (black) and ref. 35 (red). Two spline fits (lines, see Materials and Methods for details) were fitted to each data set to estimate the slope at each data point. (B) The area growth rate k as determined from Eq. (8) declines over developmental time. Colour code corresponds to the data and fits in panel A. (C,D) A model based on the dilution mechanism (Equation 2) fits the two independent wing disc growth datasets by Wartlick et al.¹⁷ (C), and by Nienhaus et al.³⁵ (D) badly; fits were obtained using the residuals given by Eq. (9) (solid lines) or Eq. (10) (dashed lines). Parameters are given in Table S1.