GFP expression experiments to test motif function. Top left: Schematic of the GFP expression constructs generated in this experiment (not to scale; for exact locations of all elements, see Additional file 3). The upstream region of gene rpl-2 (B0250.1) contained instances of motifs 12–11, 12–5, and 12–0 close together, about 380 bp upstream of the ATG. We generated six expression constructs to test the impact of the motifs on the expression of rpl-2 as follows: intact upstream region (PB); all three motifs excised (PB_del); all three motifs mutated (PB_mut); Motif 12–11 mutated (PB_mut_11); Motif 12–5 mutated (PB_mut_5); Motif 12–0 mutated (PB_mut_0). See Additional file 6 for all primers used to generate the constructs. Top right: Quantitative GFP expression signals were measured by fluorescent quantitative microscopy and scaled relative to that from worms carrying plasmid PB. Error bars indicate the standard error after four to seven measurements. Bottom: Photographs of in vivo expression of each construct.
Sleumer et al. BMC Genomics 2012 13:433 doi:10.1186/1471-2164-13-433