Adult sle⁰⁵⁷ mushroom bodies are smaller than in wild-type, with fewer neurons (of all classes). γ and α/β lobes are thinner in these mutants, while the number of α'/β' neurons is reduced dramatically, as is the number of pioneer α/β neurons. In addition, the α/β axonal bundles are already clearly visible at 24 hour after pupal formation, indicating that the pioneer α'/β' to α/β transition is not significantly delayed.

sle⁰⁵⁷ flies emerge from the pupal case one day later than wild type. The mushroom body of sle⁰⁵⁷ mutants is abnormal; the α and β lobes are thinner than in wild type and the β lobes are fused. The sle⁰⁵⁷ pupal mushroom body has half the number of neurons found in wild type and neuroblasts are significantly smaller. The initial proliferation of mushroom body neuroblasts at one day after egg laying (AEL) is the same as wild type, but sle⁰⁵⁷ neuroblast proliferation starts to decrease at 5 days AEL, a stage at which proliferation is rapid in wild type, and ceases prematurely by 9 days AEL. The relative lengths of interphase and metaphase in the mutant neuroblasts is not significantly different from wild type. Nucleolar morphology is altered in sle⁰⁵⁷ mutants. While wild-type nucleoli are variable in shape and have a roughly organized surface, sle⁰⁵⁷ nucleoli are spherical with a smooth surface and tightly organized components. This nucleolar phenotype is general as it has been observed in neuroblasts, nurse cells and imaginal wing discs. The cell cycle profile of cells in the third instar larval wing disc is not significantly different in sle⁰⁵⁷ mutants to wild type. sle⁰⁵⁷ nurse cells are abnormal and irregular in shape.