Figure 2. Expression patterns of genes from the SAGE library as assessed by gfp reporter gene technology. Only a selected and representative number of examples are shown in this figure. All analyzed reporter strains, including those shown here, are shown in Supplementary Figures 1-3. Green boxes indicate gfp coding sequences (rfp in the case of dop-3
and yfp in the case of hlh-10
). If extrachromosomal arrays were generated, multiple lines were analyzed for each reporter construct, as indicated below each panel of micrographs. Each data set of micrographs shows expression of the reporter construct under investigation in a high-magnification (400x) image, the overlap with a red fluorescent marker for ASEL/ASER (otIs151 transgene; 'ASE-RFP'), and a low-magnification (160x) overview of expression of the reporter construct under investigation throughout the whole worm. In the low-magnification images, the asterisk (*) indicates expression of the gut-specific injection marker elt-2
::gfp. (A) Expression patterns of two selected TFs from the SAGE data set. (B) Expression patterns of two selected peptidergic signaling proteins from the SAGE data set. (C) Expression patterns of two selected putative chemoreceptor proteins of the 7TMR family from the SAGE data set. The srg-30
7TMR-type chemoreceptor shows the most restricted expression pattern with strong expression in ASEL/R and weak expression in the chemosensory neurons ASIL/R and ADLL/R. Additional expression can be observed in a pharyngeal neuron. The srd-33
7TMR reporter gene fusion also shows a restricted expression pattern (ASEL/R, AWBL/R, ASHL/R, AVKL/R, PHAL/R, PHBL/R, and weakly in another unidentified tail neuron pair, possibly PHCL/R). The bottom panels in C demonstrate that 7TMR-type chemoreceptors localize to the dendritic ending of the ASE neurons. In order to boost expression in the ASE neurons, a 188-bp ASEL-specific regulatory element from the gcy-7
gene was appended to each locus (indicated as a black box). One transgenic line each was analyzed in detail. Yellow arrows point to the dendritic endings.