FIGURE 3B.

Growth gradient (G) regulation of curvature of tissue with thickness δ and at stable field cell hormesis: The morphogen concentration at the heads of the radial gradients and the slope of the gradients determine the radius of curvature and thereby the tube or cyst diameter. Top panel, ΔG₀: no growth differential (left), no curvature (right); middle panel: ΔG₁, mild growth differential, mild slope (left), mild curvature (right); bottom panel: ΔG₂, large growth differential, steeper slope (left), more curvature (right). EQDL: equidyne line.