FIGURE 2.

Sema-1a mutants show MB defects. (A) Anti-FasII staining of wild-type MBs labeling the α, β and more weakly the γ lobes. Inset: overview of the two categories of observed phenotypes. Left side of the scheme represents defects in lobe outgrowth, resulting in overextended or short lobes. Right side represents orientation defects, resulting in an abnormal angle between the vertical and horizontal lobes. (Increased angle: vertical lobes growing more lateral, or horizontal lobes growing more ventral; Decreased angle: vertical lobes growing more medial, or horizontal lobes growing more dorsal, in the most extreme case resulting in β-to-α or α-to-β misguidance.) (B) Sema-1a^CA07125/Sema-1a^K13702: anti-FasII staining. Both α and β lobes show guidance defects. One α lobe is projected parallel to the β lobe (arrow). β lobes are projected more ventrally (arrow head). (C,D) Sema-1a^CA07125/Df(2l)Exel7039 flies. (C) Anti-Dlg1 staining, labeling all MB lobes. α lobes are projected laterally (arrows), β and γ lobes have an abnormal morphology, due to outgrowth and guidance defects (arrowheads). (D) Anti-FasII staining. One α lobe is projected ventrally (arrow). (E) Summary of the different MB lobe defects observed in Sema-1a^CA07125 homozygotes and Sema-1a^K13702/Sema-1a^CA07125 or Sema-1a^CA07125/Df(2L)Exel7039 heterozygotes. [Dorsal- lateral (D-L) misorientation, ventral- medial (V-M) misorientation, short, overextension].