Fig. 1: RNA-Seq strategy to examine genomic response to dietary iron.
From: New molecular components of high and low affinity iron import systems in Drosophila
A X-Ray Fluorescence Microscopy (XRF) images of BRGC (brain-ring gland complex) samples and quantification of iron levels in the ring gland (RG) and central nervous system (CNS). Larvae were reared for one generation on iron-enriched (+i), normal (N), and in iron-depleted (−i) media, and BRGCs were dissected from L3 larvae. Average iron concentrations in the RG, (red dotted line) and CNS (white dotted line) were calculated from three replicates based on Kα emission/area ratios. Dotted lines indicate regions used to measure iron levels. Scale bars: 30 µm. The color scale bar reflects log2-based iron levels. Asterisks denote significance thresholds (*p < 0.05 and ***p < 0.001). B Survival rates and developmental progression of fly populations as a result of multi-generational iron deprivation. w1118 flies were reared for five generations (G1–G5) on either a normal diet (N) or media supplemented with BPS. Y-axes denote the percentage of pupariated animals, and X-axes show hours after egg deposition. Dotted line indicates 50% pupariation. Error bars indicate standard deviation from three biological replicates; means are centered. C Schematic of the RNA-Seq experimental design. Eggs from G5 flies reared on iron-depleted media (see B) were used to produce the G6 generation. G6 larvae were staged within 30 min after the L2/L3 molt and split into two groups: one cohort was transferred to iron-supplemented food (FAC) and the other to fresh iron-depleted media. At 4, 8, 12, and 16 h after the L2/L3 molt, BRGC (Ring gland = green, CNS = yellow), guts (red) and whole larvae (WB = whole body) were collected. L1/L2/L3 denote first, second, and third instar larvae. D Venn diagram summarizing RNA-Seq results for a total of 683 differentially expressed genes for i) the BRGC (88 genes), ii) the gut (486 genes) and iii) WB (176 genes). Example genes shown for selected sections. Green: known iron-related genes. Source data are available in the accompanying source data file.
