Fig. 6

Site-directed mutagenesis defines DNA motifs required for intestinal expression.

(A) Scaled schematic showing 10 bp substitution blocks tiled across the zebrafish angptl4 in3.11 region within the context of the entire in3.4 intestinal module. Black or blue blocks represent mutations that do or do not significantly alter intestinal expression compared to wild type in3.4, respectively (see below). Ratios of intestine positive fish versus total fish expressing GFP are shown in parentheses above or below substitution block labels. (B) Relative mean intestinal fluorescence was quantified in mosaic animals (see Materials and Methods) and plotted per injected fish. Circles represent mean fluorescence averaged for three mosaic patches within a single fish and are colored blue or black to designate mutations that do or do not confer intestinal expression, respectively. Statistical significance was tested using Kruskal-Wallis one-way analysis of variance (labels: a = P<.01 vs. in3.4, P>.05 vs. Fos; b = P>.05 vs. Fos; unlabeled = P>.05 vs. in3.4, P<.01 vs. Fos). (C) Images from animals with mosaic expression of five representative mutant constructs are shown. Blue arrows indicate intestinal expression (in). Scale bars = 100 μm.