We generated a more complete
drl-1p::GFP reporter by fusing GFP coding sequence to a 5.1 kb genomic fragment that includes the upstream intergenic region and intron 1 and co-injected it with pharynx marker
myo-2p::tdTomato.
drl-1p::GFP was expressed in the epidermis and intestine consistent with previous mRNA enrichment studies (Pauli et al. 2006; Spencer et al. 2011; Blazie et al. 2017; Han et al. 2017). These results suggest that the upstream intergenic region drives expression in the intestine and that intron 1 also permits expression in the epidermis. A prior study failed to observe intestinal expression with a
drl-1 transcriptional reporter (Chamoli et al. 2014); however, this former construct lacked the intergenic region upstream from exon 1 that drives intestinal expression.