Fig. 4. CA babo misexpression results in MB axon truncation. babo and wit genetically interact with LIMK1. (A-D) Drosophila MB neurons misexpressing CA babo (A,A'), CA tkv (B), CA sax (C) or LIMK1 (D). Solid red or white arrowheads indicate normal and β or lobe termination points, as indicated. Open red or white arrows indicate axon truncations in and β lobes, or in lobes, respectively. In D, the cell body section was removed to clearly reveal axon phenotypes. Scale bar: 20 µm. (E) Quantification of axon growth defects in LIMK1-overexpressing neurons (using intermediate expression line F4) in the presence of control (y, w), or one copy of each TGFβ receptor mutant. Phenotypic quantifications were carried out as described previously (Ng and Luo, 2004), and are briefly summarised in the key. n, number of hemispheres examined.