Fig. 4. ptpmeg is required to prevent the retraction of MB dorsal lobe axons. (A) Dorsal MB lobe defects in control and ptpmeg¹/Df(3L)ED201 animals over developmental time. (B-M) Representative left hemispheres. MB neurons visualized with OK107-Gal4;UAS-mCD8:GFP. Control (B-G) and ptpmeg¹/Df(3L)ED201 mutant (H-M) are shown for each age. Arrowheads in L and M indicate thin dorsal lobe in ptpmeg. Inset in L is a high magnification view of an lobe (visualized using FasII) that has partially withdrawn. Small arrowheads denote the concentrations of material that are occasionally observed.