Fig. 5. Axon guidance phenotypes in the double mutants. (A-F) Lateral view of juIs76[Punc-25GFP] in different genetic backgrounds. In wild type (A) and ina-1(gm144) (C) animals commissures (arrow) all reach the dorsal cord. In unc-71, fewer commissures (arrow) grow out and some stop short (arrowhead in B). (D) In unc-71(ju156); ina-1(gm144) animals, even fewer commissures (arrow) grow out. (E) In unc-6(ev400) animals, few commissures (arrow) grow out but all are defective. (F) In unc-71(ju156); unc-6(ev400) animals, no commissures grow out of the ventral cord. Arrow indicates the lateral positions where commissures would be found in unc-6 mutants. (G-J) Ventral view of juIs76 in different genetic backgrounds. (G) DD and VD ventral processes are fasciculated forming a tight bundle (arrow) in wild-type animals. (H,I) DD and VD ventral processes are defasciculated in unc-71(ju156) and ina-1(gm144) animals as two separated processes (arrow). (J) The ventral cord (arrows) is largely disorganized in unc-71(ju156); ina-1(gm144) animals. (K-N) DA and DB motoneurons in different genetic backgrounds viewed by juIs14[Pacr-2GFP]. In wild type, all commissures reach the dorsal cord (arrowhead in K); in unc-71(ju156) occasionally one commissure does not reach the dorsal cord (arrowhead) but instead runs laterally (arrow in L); in unc-6(ev400) none of the commissures reaches the dorsal cord (arrowhead in M) and all run laterally (arrow in M); in unc-71(ju156); unc-6(ev400) double mutants none of the commissures reaches the dorsal cord (arrowhead) and all run laterally (arrow in N), which is similar to unc-6 alone (M). Scale bars: in A, 50 µm for A-J; in K, 50 µm for K-N.