Knockdown of NetA through expression of NetAdsRNA.Scer\UAS in photoreceptor axons (under the control of Scer\GAL4Scer\FRT.Act5C and Scer\FLP1ey.3.5.hs) does not cause any R8 axon-targeting errors. Knockdown in the target area (through expression under the control of Scer\FLP1ey.3.5.hs, Scer\GAL80ey.3.5, Scer\GAL4Scer\FRT.Act5C and Scer\GAL4GMR.long) results in R8 axons stalling at the medulla neuropil border instead of terminating in the M3 layer.