Figure 5. Sns and Duf are required for nephrocyte filtration.

a,c,d, Third instar garland nephrocytes from wild-type (a), duf (c) and sns RNAi knockdown (d) animals co-incubated with 10,000mw (magenta) and 500,000mw (green) fluorescently-labelled dextran. Inset in c,d shows merged image of transmitted light and 500,000mw channels. b,e, Schematic drawing of filtration and endocytosis in wildtype (b) and sns or duf mutant (e) nephrocytes. f, Quantification of small (magenta) and large (green) dextran uptake in wild-type, duf and sns RNAi knockdown garland cells. Pixel number exceeding threshold is shown on Y-axis (error bars, S.E.M). nb, the molar ratio of dye:dextran is 1:1 (for 10,000mw) and 64:1 (for 500,000mw). g, control nephrocyte incubated with fluorescent dextran at 4°C showing no uptake (gⁱ). h, 10μm section of garland nephrocytes from a wild-type larva fed with AgNO₃ (brown granular staining). i, Percentage of eclosing sibling control or duf adults fed yeast paste (grey) or yeast paste with AgNO₃ (blue) (n = 65, 68, 55 and 57).