Figure 5. Similar Axon Navigation Defects in
ina-1- and
mig-15-Deficient Animals. (A) A schematic diagram of C. elegans GABAergic neurons: the name of all GABAergic neurons are indicated below the cell bodies (white circles); DC, dorsal cord; CO, commissure; VC, ventral cord. Anterior is oriented toward the left, and dorsal is oriented upward. Note that most commissures are on the right side of the animal (curved lines pointing to the tail), while two in the head are on the left side (curved lines pointing to the head).(B) GFP autofluorescence of a wild-type control animal carrying the
unc-47::gfp transgene expressed in all GABAergic neurons.(C-J) Commissures from a (C)
mig-15(RNAi) animal, a (D)
mig-15(
rh148) mutant, an (E)
ina-1(
gm144) mutant, an (F)
ina-1(
gm119);
mig-15(
rh148) double mutant, an (G)
ina-1(
gm144);
mig-15(RNAi) mutant, an (H and I) animal carrying a transgene expressing
mig-15 dsRNA and
pat-3 dsRNA, respectively, under the control of the
unc-25 GABAergic promoter, and an (J)
ina-1(
gm144) mutant after stable
mig-15 RNAi under the control of the
unc-25 promoter. All animals carry the
unc-47::gfp construct. Note that most animals have meandering commissures and/or prematurely branched commissures (arrows) that generally lead to a disruption of the dorsal cord (arrowheads), and that the defects are significantly more severe when animals are defective for both
ina-1 and
mig-15.(K) Upper panel, expression of
mig15::gfp in neurons of an L2 larva in the area of P7.p-P8.p cells (ventral side is up); lower panel, DIC (differential interference contrast) picture of the same animal (only the ventral cord is shown).(L) Expression of
mig-15::gfp in the dorsal cord (DC) in an L3 animal.(M) Expression of
mig-15::gfp in the ventral cord (VC), body wall (BM), vulval (VM) muscles, and vulva (V) of a young adult. In panels (H)-(M), the animal appears to be twisted because of the dominant marker
rol-6(
su1006) used as a cotransformation marker. The scale bar represents 30 μm in (B)-(L) and (M) and 6 μm in (K).