prel1 mutant third instar larvae display fragmentation of mitochondria in the cell body and shortening of dendritic arbors in the class IV ddaC neurons, the reduction of dendritic arbor is also observed in class I ddaE and class III ddaA neurons although the phenotype in these two neuronal classes is much weaker.
Homozygotes die as early larvae.
The density of mitochondria (assayed by the expression of markers with a mitochondrial targeting signal) is significantly reduced in both axons and dendrites of homozygous ddaC neuron clones compared to controls. The mitochondria appear to be fragmented in the mutant neurons.
Homozygous ddaC neuron clones have shorter, smaller and much less-branched dendritic arbors compared to control neurons. The terminal branches tend to be shorter than those of wild-type neurons, making the mutant distal dendrites appear fuzzy. Some detached branches are seen in the mutant arbor, with the breakages occurring more frequently in the proximal area of the arbor than in the distal area. No axonal breakage (at least not close to the cell body) is seen in the mutant neurons.