Overview of potential biological interactions of JH (methyl farnesoate) in Daphnia magna. Expression of relevant target genes in ibuprofen-stressed daphnids (24 to 48 hours of exposure) is indicated by small arrows quantified by either microarrays (normal font) or quantitative PCR (bold font). Note that 20-hydroxyecdysone is the main hormone controlling moulting in Daphnia, whereas juvenile hormone (JH; in arthropods) prevents sexual maturation between moults in juveniles. (There is currently no evidence from daphnids on this role.) Large arrows signify synthesis or induction of the particular product or process, whereas end bars denote inhibition. Abbreviations are as in Additional data file 1 and Figure 1; CP genes signify cuticle protein genes (see text for further details).