Figure 1. The expression pattern of unc-47
is conserved despite divergent regulation. (A) Both C. elegans and C. briggsae promoters fused upstream of GFP in their endogenous trans-regulatory environments drive expression in all 26 GABAergic neurons (green). However, the C. briggsae promoter placed in the C. elegans trans environment additionally drives expression in SDQR and SDQL (blue). (B) Those cells were identified as SDQR/L based on their position and their characteristic projections. (C) For each combination of promoter and trans-regulatory environment, expression in SDQR and SDQL is presented. C. elegans is represented by straight lines, C. briggsae by wavy lines. Frequency of expression is represented by the width, and intensity of expression relative to D-type neurons by the height of black boxes. Number of individuals expressing and total number of individuals scored is indicated underneath. Measurements for independent strains are given in Figure S1. Differences in frequency of expression in SDQR are significant for all comparisons: C. elegans and C. briggsae promoters in C. elegans trans environment (p = 8.1610212), C. elegans and C. briggsae promoters in C. briggsae trans environment (p = 1.561028), C. elegans promoter in C. elegans and C. briggsae trans environments (p = 4.8610211), C. briggsae promoter in C. elegans and C. briggsae trans environments (p = 2.4610214). (D) Interpretation of the results presented in panel C. Both C. elegans and C. briggsae promoters in their endogenous trans environments drive low levels of expression in SDQR and SDQL, while disruption of the endogenous interactions either drives high levels of expression (C. briggsae promoter in C. elegans) or abolishes expression (C. elegans promoter in C. briggsae).