In fne^KOZ40 mutant class IV da neurons show increased number of terminal branches in L1 and L2, although a decrease in branches close to the soma at L3; there is decreased branch length in L1 to L3 and decreased total branch length in L1 and L2; there is an increase in isoneuronal dendrite crossing events, the full arbor has increased empty space in L3, with a decrease in field coverage. Unlike controls, the dendritic arbor is mostly cleared by 7h after puparium formation. There is an increase in both new and lost dendritic branches during L3. Arbors show a decrease in stable microtubules compared to controls. There is increased enclosure of terminal branches and increased crossovers between enclosed dendrites.

fne^KOZ40 mutants are viable, but exhibit a specific and fully penetrant fusion of the β-lobes in their mushroom bodies. Mutant males display reduced courtship indices, but normal short- and long-term courtship memory.

In a small fraction of fne^KOZ40 brains, there is an apparent fusion of the medially projecting lobes of the mushroom body (β lobes) at the midline, both in males and in females. The majority of the fne^KOZ40 brains are indistinguishable from hemizygous males or from heterozygous fne^KOZ40/+ female brains, with β axon fibers terminating near the midline without crossing it. No other alterations in the mushroom body loves, specifically α, β and γ are detected. The ellipsoid body, one of the four neuropils of the central complex, is maintained in fne^KOZ40 mutants.

fne^KOZ40 has larval multidendritic class IV neuron | larval stage phenotype, non-enhanceable by Bsg^HMC03195/Scer\GAL4^ppk.PG

fne^KOZ40 has dendritic branch | larval stage phenotype, non-enhanceable by Bsg^HMC03195/Scer\GAL4^ppk.PG

fne^KOZ40 has dendritic tree | larval stage phenotype, non-enhanceable by Bsg^HMC03195/Scer\GAL4^ppk.PG

fne^KOZ40 has larval multidendritic class IV neuron | larval stage phenotype, suppressible by mys^UAS.cDa/mew^UAS.cMBb/Scer\GAL4^ppk.PG

fne^KOZ40 has dendritic branch | larval stage phenotype, suppressible by mys^UAS.cDa/mew^UAS.cMBb/Scer\GAL4^ppk.PG

fne^KOZ40 has dendritic tree | larval stage phenotype, suppressible by mys^UAS.cDa/mew^UAS.cMBb/Scer\GAL4^ppk.PG

fne^KOZ40 has larval multidendritic class IV neuron | larval stage phenotype, non-suppressible by Bsg^HMC03195/Scer\GAL4^ppk.PG

fne^KOZ40 has dendritic branch | larval stage phenotype, non-suppressible by Bsg^HMC03195/Scer\GAL4^ppk.PG

fne^KOZ40 has dendritic tree | larval stage phenotype, non-suppressible by Bsg^HMC03195/Scer\GAL4^ppk.PG