(A) Representative images of Plin3-RFP and EGFP-Plin2 fluorescence in the intestine of 6 days post fertilization (dpf) larvae at noted time-points following the onset of a 90 min high-fat meal. Scale = 500 µm. (B) Fluorescence intensity was quantitated every hour for the first 8 hr following onset of the meal and subsequently every 2 hr for a total of 30 hr. Mean fluorescence intensity of wild-type siblings at each time-point was used to correct for gut autofluorescence. Black circles and errors bars indicate mean ± SD, individual data points are shown in gray, n = 14–23 total larvae per time-point from three independent clutches. Significant changes in fluorescence between unfed (0 hr) and subsequent time-points were calculated with Kruskal-Wallis with Dunn’s multiple comparisons tests. For Plin3-RFP, fluorescence is significantly different from 0 hr at 6 and 8–28 hr, p < 0.05. For EGFP-Plin2, fluorescence is significantly different from 0 hr at 5–18, 22, and 24 hr, p < 0.05. Refer to Figure 2—source data 1 file for p-values at each time-point. (C) Example brightfield images and corresponding EGFP-Plin2 fluorescence images from larvae imaged 10 hr after the onset of the meal. The degree of intestinal opacity reflects the amount of lipid consumed. Scale = 500 µm. (D) EGFP-Plin2 fluorescence intensity of individual larvae 10 hr after the onset of the meal was plotted as a function of the mean gray value of the intestine in the corresponding brightfield image. The amount of lipid consumed (intestine opacity) predicts much of the EGFP-Plin2 fluorescence (simple linear regression, y = –96314x + 130885876, R2 = 0.6828, p < 0.0001).
