Overall antennal lobe morphology is disrupted in Sema-2a03474 Sema-2bunspecified double homozygous flies. Dendrite targeting defects are seen for a number of projection neurons. The dendrites of the DL1 projection neurons are either split between the DL1 glomerulus (wild-type target) and an ectopic ventromedial position or entirely shifted ventromedially. DL3 projection neuron dendrites mistarget ventrally or ventromedially. VA1d and DA1 projection neuron dendrites mistarget ventromedially and ventrolaterally. VM2 projection neuron dendrites show significant dorsolateral mistargeting.
Sema-2a03474/+ Sema-2bunspecified/Sema-2bunspecified flies show a small but significant ventromedial shift of Mmus\Cd8aMz19-positive projection neuron dendrite targeting. There is an additional significant ventromedial shift for these dendrites if the flies are also expressing Sema-2aGD5476 under the control of Scer\GAL4peb-GAL4.
In Sema-2a03474 Sema-2bunspecified double mutant projection neuron anterodorsal neuroblast clones generated between 0-24 hours after larval hatching (ALH), VM2 projection neuron dendrites mistarget dorsolaterally. In contrast, if the double mutant clones are generated between 48-72 hours ALH, VM2 dendrites target normally to the ventromedial VM2 glomerulus.