Figure 4. LGC-55 is required for the tyraminergic modulation of head movements by C. elegans and is expressed in the GLR glia-like cells and head muscles. (A) The fractions of animals that have the Sho phenotype and cannot suppress head oscillations are plotted for the wild type,
tdc-1 and
lgc-55 mutants, and
lgc-55 mutants carrying rescuing transgenes that express the
lgc-55 cDNA using its own promoter, the pan-neuronal
unc-119 promoter, or the pan-muscle
myo-3 promoter. In each experiment, we tested 20 individuals of each genotype for the Sho phenotype. The mean fraction of animals with the Sho phenotype +/- SEM is plotted, n > 3. Three independent lines (labeled #1 to 3) carrying each transgene were assayed. (B) Expression of
lgc-55. An
lgc-55::gfp reporter transgene is expressed in the GLR glia-like cells and head muscles (17). Arrowheads indicate some of the unidentified head neurons that express the reporter transgene. The tyraminergic RIM neurons, which provide the tyramine that inhibits head movements during reversals, are labeled with a
tdc-1::dsRed reporter transgene.