Fig. 9. Misexpression of zig-4 causes PVQL/R axon patterning defects. PVQL/R defects can be observed in animals that misexpress zig-4 under the control of the flp-1 promoter, expressed in the AVKL/R neurons (A), or the myo-3 promoter, expressed in body wall muscles (BWM; B). Animals were scored as adults to reveal maintenance defects (left panels, `Adult') and a subset of those lines were scored as freshly hatched L1 animals to allow scoring for embryonic defects (right panel, `Embryo'). Numbers within bars represent sample size. The broken `control line' in B refers to the average value of the five BWM::control lines that were scored as adults (left). We could not score control lines as freshly hatched larvae (as in A) because of a strong myo-3::gfp background signal. `Control' refers to the respective promoter driving expression of gfp. The kal-1 gene, which codes for a secreted protein (Bülow et al., 2002) was used as an additional control. Control and transgenic lines all contain oyIs14 in the background to allow scoring PVQL/R anatomy.