We expressed GFP under the control of a 2.7 kb DNA sequence upstream of the CRH-1e translation start site (henceforth termed as
pcrh-1e). Consistent with remarkably low levels of expression in qPCR measurements, we could observe the GFP expression in the
pcrh-1e::GFP line in only a few head neurons, expression in the head neurons was also seen previously by Kimura et al who had done in situ hybridization of the
crh-1 gene (Kimura et al., 2002). Colocalization experiments showed that the overlap in expression pattern of
pnmr-1 was largely restricted to three pairs of neurons. Based on the position of the overlapping neuron, we assessed that localization was seen in the AVA, AVE and RIM interneurons. The same was confirmed by co-expression experiments using neuron specific promoter marker lines for AVA (
prig-3::mCherry), AVE (
popt-3::mCherry) and RIM (
pgcy-13::mCherry) (Fei et al., 2000; Feinberg et al., 2008; Ortiz et al., 2006). We found that
pcrh-1e::GFP localized with all these neurons.