Fig. 4. Induction of hemoglobin in daphnids (Daphnia magna) exposed to 0 or 3 nmol l^-1 pyriproxyfen. (A) Control (0) and exposed (3) daphnids. (B) Electrophoretically separated pigmented protein from individual control (0) and exposed (3) daphnids. (C) Hemoglobin protein levels (µg mg^-1 protein) in daphnids by absorbance at 415 nm (dark bars) and relative hb2 mRNA levels, normalized to levels of actin transcripts, measured by real-time rtPCR (light bars). Hemoglobin protein levels are means ± S.E.M. (N=4 samples each prepared from 17-20 individuals). Hemoglobin mRNA levels are means ± S.E.M. (N=2 samples each prepared from 30 individuals). ^*Significant (P<0.05) difference between control and pyriproxyfen-treated daphnids (Student's t test).