fzy⁵⁰³² larval brains show progressive neuroblast loss.

35% of fzy⁵⁰³² mutant clones generated in the brain during the larval stages do not contain neuroblasts, compared to <10% in controls.

As in wild type, fzy⁵⁰³² mutant neuroepithelial cell clones in the larval optic lobe proliferate to generate a large number of progeny.

Unlike in wild type, many fzy⁵⁰³² mutant neuroblast clones in the larval brain fail to proliferate.

fzy⁵⁰³²/fzy⁴ mutant neuroblasts maintain a single nucleus and cell diameters are similar to wild type.

fzy⁵⁰³²/fzy¹ larval brains show progressive neuroblast loss.

fzy⁵⁰³²/fzy¹ mutant adults possess all appendages but have a dramatically reduced neuropil compared to controls. They exhibit poor motor function.

fzy⁵⁰³²/fzy¹ mutant exhibit morphological and molecular marker changes consistent with aberrant onset of necrosis: in contrast to wild type, neuroblasts in fzy⁵⁰³²/fzy¹ mutant brains often do not have identifiable nuclei, and their cytoplasm appears largely devoid of organelles and vacuoles. In these neuroblasts mitochondria are swollen and ruptured and remnants of the endoplasmic reticulum clump with remaining mitochondria into electron dense aggregates. Mitochondrial aggregates are seen in 25% of remaining fzy⁵⁰³²/fzy¹ mutant neuroblasts. Elevated levels of reactive oxygen species and calcium ions are seen in fzy⁵⁰³²/fzy¹ mutant neuroblasts compared to controls. Almost 40% of fzy⁵⁰³²/fzy¹ mutant neuroblasts contain ubiquitin-conjugated protein aggregates, and these are virtually non-existent in controls.