Drosophila Zip1 (dZip1) and dZip2 are zinc-specific transporters involved in dietary zinc absorption. (A) Gut-specific knockdown of dZip2 or of dZip1 dZip2 in combination resulted in impaired larval development under zinc deficiency (0.3 mmol/l EDTA). (B) Reverse transcriptase (RT)-PCR analysis of the knockdown effect of the dZip1-RNAi and dZip2-RNAi lines. rp49 was used as the loading control. (C) Ubiquitous knockdown of either dZip1 or dZip2 produced a reduction in alkaline phosphatase (ALP) activity but did not affect aconitase activity. (D) Gut-specific knockdown of either dZip1 or dZip2 similarly led to reduced ALP activity of whole body minus gut in flies fed on 0.1 mmol/l EDTA-supplemented food. (E) dZip2-RNAi and dZip1-, dZip2-RNAi flies are specifically sensitive to zinc deficiency. The survival rate of these RNAi flies on EDTA-supplemented food could be rescued by adding back zinc but not other metals. (A,D) Genotypes of flies used were NP3084/+, NP3084/+; dZip1-RNAi/+ (dZip1-RNAi fly), NP3084/+; dZip2-RNAi/+ (dZip2-RNAi fly), NP3084/+; dZip1-, dZip2-RNAi/+ (dZip1-, dZip2-RNAi fly). (B,C,E) Genotypes of flies used were da-GAL4/+ for control and da-GAL4/dZip1-RNAi for dZip1-RNAi, da-GAL4/dZip2-RNAi for dZip2-RNAi, and da-GAL4/dZip- dZip2-RNAi for the double RNAi fly. Values are presented as means ± SEM; n ≥ 3. *P < 0.05, **P < 0.01, ***P < 0.001; one-way ANOVA.