In chick, ephrin-A2 is found in an increasing gradient from anterior to posterior tectum. Researchers virally misexpressed ephrin-A2 in patches throughout the tectum and then visualized the temporal RGC axons that expressed high levels of its receptor EphA3. What result would demonstrate the sufficiency of ephrin-A2 for repulsion?
Answer
If ephrin-A2 is sufficient to repulse RGC axons expressing EphA3, then the temporal axons should target the anterior tectum but avoid the patches of virally misexpressed ligand.