Real-time detection polymerase chain reaction (copy number/10 ng total RNA) of messenger RNA (mRNA) of Helix pomatia HpCdMT and HpCuMT (a) and Cantareus aspersus CaCdMT, CaCuMT and CaCd/CuMT (b). Respective mRNA concentrations (copy numbers/10 ng total RNA) were measured in midgut gland tissue of control (unexposed) snails at the beginning of the experiments and of controls, as well as metal-exposed snails, after a feeding period of 5 days. For each bar, means and standard deviations are shown (n = 5). Asterisks above bars designate significant deviations (T-test, P ≤ 0.05) from control animals at the beginning of the experiment. For controls, copy numbers are specified above bars. Respective metal concentrations in the feed are shown below each bar, expressed as μmol metal/g dry weight of feed. MT, metallothionein.
Palacios et al. BMC Biology 2011 9:4 doi:10.1186/1741-7007-9-4