Which of the following schematic drawings better depicts the regulatory network that maintains Engrailed (en), Hedgehog (hh), and Wingless (wg) expression following cellularization in a developing Drosophila embryo?

Question

Quizplus · Accepted Answer

In each segment, cells that express the signal protein Wingless induce their neighboring cells to express the transcription regulator Engrailed, which activates the expression of the signal protein Hedgehog in these cells. This in turn activates the expression of Wingless in the first cell, maintaining the fine patterning within the segment.

Which of the Following Schematic Drawings Better Depicts the Regulatory