Fig. 5: Mco4 is required for iron uptake into the prothoracic gland.

A RNA-Seq analysis of Mco4 expression in G6 BRGCs from larvae reared on BPS- or FAC-supplemented (iron-rich, normalized to 1) diets. B qPCR analysis of Mco4 in ring glands (RG) of control (w¹¹¹⁸) larvae at 12, 16 and 44 h after L2/L3 molt. Larvae were reared on normal (no suppl.) and on BPS- (iron-depleted) diets. C qPCR analysis of Mco4 expression in the carcass, gut, proventriculus (PV), and gut without proventriculus (gut w/o PV) of control (w¹¹¹⁸) larvae reared on normal (no suppl.) or BPS-supplemented diets. In (B, C), expression data are based on three biological replicates, each tested in triplicate. Error bars represent 95% confidence intervals, asterisks denote significance by two-sided Student’s t test (***p < 0.01). D Brightfield images of Mco4 in situ hybridization in control (w¹¹¹⁸) guts from larvae reared on normal or BPS-supplemented diets. Scale bars: 150 µm. E Immunodetection of Mco4 in the proventriculus (PV) of Mco4^3xFLA knock-in larvae. Blue: nuclei (DAPI), gray and green: Mco4 signal. Scale bars: 100 µm. F qPCR analysis of Mco4 expression in ring glands (RG) from PG > AGBE^IR and PG>Evi5^IR larvae, normalized to PG > w¹¹¹⁸ controls (set to 1). G qPCR analysis of ALAS expression in ring glands from PG > AGBE^IR and PG > AGBE^IR; Mco4^KO larvae. F, G Data are from three biological replicates, each tested in triplicate. Error bars: 95% confidence intervals; asterisks: two-sided Student’s t test (***p < 0.01). D–G All larvae were dissected at 44 h after the L2/L3 molt. H Red autofluorescence in ring glands of i) control, ii) Mco4^KO, iii) PG > AGBE^IR and iv) PG > AGBE^IR; Mco4^KO larvae reared on normal (no suppl.), iron-rich (+FAC) and iron-depleted (+BPS) diets. UV ultraviolet, BF brightfield. Scale bars: 250 µm. I Developmental timing analysis of control, Mco4^KO, PG > AGBE^IR and PG > AGBE^IR; Mco4^KO larvae reared on normal (no suppl.) or BPS-supplemented diets. Y-axis: percentage pupariated. X-axis: hours after egg deposition. Dotted line marks 50% pupariation. Error bars: standard error (n = 3); center lines in (B, C, F, G, and I) represent means. Source data are provided in the accompanying source data file.