Fig. 2.
unc-40 functions cell-autonomously to regulate muscle arm extension. (A-E') Dorsal (A-E) and ventral (A'-E') views of muscle arms of C. elegans animals of the indicated genotypes. The annotation is the same as in Fig. 1. (D,D') UNC-40::YFP was expressed in the nervous system using the
unc-119 promoter (neuro-p in F). The white arrow in D points to the area where the DR15 muscle is normally positioned, but is not fluorescing in this animal. (E,E'). UNC-40::YFP was expressed in the distal muscles using the
him-4 promoter (muscle-p in F). (F) The average number of muscle arms extended by the indicated genotypes. The control transgenes are the DNAs common to all injection mixtures without the experimental
unc-40-related transgene (see Materials and methods). Aside from trIs34, the transgenic arrays are maintained extra-chromosomally, independent lines of which are indicated with a number. Additional annotation is the same as for Fig. 1G. (G) The number of lateral muscle membrane extensions for the indicated genotypes, illustrating that
unc-40 mutations suppress misdirected muscle arm extension to misguided lateral axons resulting from an
unc-5 or
unc-6 mutant background. Asterisks indicate significantly more defects than the controls (P<0.001) as indicated by the lines above the bars. The error bars in F and G represent s.e.m. (H) UNC-40::GFP expression directed by the
unc-40 promoter. Localization to the muscle plasma membrane is indicated. (I) Muscle-specific expression of functional UNC-40::YFP, driven by the
him-4 promoter. Enrichment at the muscle arm terminus is indicated. Scale bars: 50 μm in A-E'; 10 μm in H,I.