Application of the Drosophila melanogaster Research Model to Evaluate the Toxicity Levels between Lead and Copper.

Applications of the Drosophila melanogaster (D.m.) research model have an important means both for genetic investigations and for the study of metal toxicity, because D.m. has physiological mechanisms comparable to those in human organisms. In this research, the toxic effect of lead (Pb²⁺) and copper (Cu²⁺) on four D.m. genotypes—the wild genotype (Oregon-R, used as control) and three mutant genotypes (white, brown, and white-vestigial)—was compared. Five replicates were made to observe the development progress of monitorized genotypes exposed to five different concentrations 0, 0.50, 0.75, 1.00, and 2.00 mM of copper (CuSO₄) and lead Pb(C₂H₃O₂)₂. Proliferation rates of larvae, pupae, and adults depend on genetic factors, metals used (copper or lead), and their concentrations. The white-vestigial mutant genotype showed the greatest sensitivity at IC₅₀ concentration (inhibition of proliferation of more than 50% compared with the control sample) at doses of 1.00 mM for Cu²⁺ and 2.00 mM for Pb²⁺. In contrast, the control genotype (Oregon-R) showed only an inhibition IC₅₀ concentration of 2.00 mM for Cu²⁺. The white-vestigial mutant genotype showed the greatest sensitivity at IC₅₀ concentration (inhibition of proliferation of more than 50% compared with the control sample) at doses of 1.00 mM for Cu²⁺ and 2.00 mM for Pb²⁺. In contrast, the control genotype (Oregon-R) showed an inhibition at the IC₅₀ concentration of 2.00 mM for Cu²⁺. The results conclude that (i) the dose influences the prolificacy rate in a directly proportional way, (ii) the comparative analyses between Cu²⁺ and Pb²⁺ revealed a more acute effect of Cu²⁺, and (iii) differentiated prolificacy values according to genotypes were recorded. Those reflect the importance of using D.m. as a research model in the comparative studies of the interactions between genetic factors and metal toxicity. Also, this study provides significant information on non-toxic maximum doses for organisms. [ABSTRACT FROM AUTHOR]