Figure 1
From: Spalt expression and the development of melanic color patterns in pierid butterflies
One or two signaling centers? A) The slight dumbbell-shaped Pieris rapae spot may have a single signaling group of cells at its center or two off-center signaling sources, one producing the anterior half of the spot, and the other the posterior half. B) Late P. rapae pupal wing showing the area that was targeted for piercing with underlying pigmented spot (the darker spot was not visible when operations were performed on younger pupal wings). C) The three different locations targeted for piercings on the young pupal wings.