Homozygous mushroom body γ neuron clones appear normal at the third instar larval stage, but show a severe pruning defect at the pupal stage: the dorsal and medial γ-axon branches and their dendrites are retained at 18 hours after puparium formation, in contrast to wild type. The unpruned axons persist into the adult stage as dorsal branches that lie outside the α-lobe.

Mushroom body neuroblast clones expressing plum^{Scer\UAS.T:Zzzz\FLAG} under the control of Scer\GAL4^Tab2-201Y in a homozygous plum^Δ1 brain show weaker pruning defects compared to plum^Δ1 clones in an otherwise heterozygous plum^Δ1 brain.