Overexpression of Kctd12.2 inhibits elaboration of Hb neuropil. A, Kctd12.2 (green) is normally expressed in neurons of the medial subnuclei. B, In Hb:Gal>Kctd12.2-MT larvae, expression of Kctd12.2-MT fusion protein is driven at high levels in nearly all Hb neurons. C, D, WT larvae have an elaborate network of neuropil that segregates within each Hb subnucleus (C), but the presence of high levels of ectopic Kctd12.2-MT fusion inhibits the elaboration of Hb neuropil (D). E, Volumetric quantification of Hb neuropil reduction. Overexpression of Kctd12.2-MT causes a significant reduction of total Hb neuropil volume compared with WT (18,103 ± 789 vs 30,147 ± 2588 μm3; p = 7.7E-8; n = 16). All subnuclei are significantly affected (asterisks indicate statistical difference compared with WT). Scale bars, 50 μm. *p < 0.05, **p < 0.01, two-tailed t test.