Figure 1.

Nab2 is required during pupal development for proper neuromorphological patterning of the mushroom bodies.A, diagram of the Drosophila mushroom body depicting cell bodies (dashed lines) projecting axons that bundle to make the dorsal (α) and medial (β) lobes that are mirrored across the brain midline (dashed line). B, Fasciclin II (FasII) antibody staining of control (C155>Gal4, w¹¹¹⁸) and Nab2^ex3 (C155>Gal4;;Nab2^ex3) brains 48 to 72 h after puparium formation. Confocal images show maximum intensity Z-stack projections (projection) that display full mushroom bodies and single transverse plane sections (single section) that display midline crossing of β-lobe axons. Imaging reveals that control rarely shows defects in α- and β-lobes, while Nab2^ex3 brains often have thinning or loss of the α-lobes and β-lobes that project across the midline into the contralateral hemisphere resulting in the fusion of the lobes or occasionally loss of β-lobes. The ellipsoid body (donut-shaped structure at the brain midline) is visible in maximum intensity projection images that mask the β-lobe status, so single section images are included for clarity. C, quantification of the frequency of control and Nab2^ex3 (left) total α-lobe defect (thinning or missing α-lobe) or (right) total β-lobe defect (fusion or missing β-lobes) using the scoring system as described in Experimental procedures. Control (α-lobe = 11 biological and 22 technical replicates; β-lobe = 11 biological and technical replicates) and Nab2^ex3 (α-lobe = 17 biological and 34 technical replicates; β-lobe = 17 biological and technical replicates). The asterisk indicates p < 0.05; α-lobe p = 0.002; β-lobe p = 0.007.