Using the pea aphid Acrythociphon pisum as a tool for screening biological responses to chemicals and drugs.

Background: Though the biological process of aphid feeding is well documented, no one to date has sought to apply it as a tool to screen the biological responses to chemicals and drugs, in ecotoxicology, genotoxicology and/or for interactions in the cascade of sequential molecular events of embryogenesis. Parthenogenetic insect species present the advantage of an anatomical system composed of multiple germarium/ovarioles in the same mother with all the intermediate maturation stages of embryos from oocyte to first instar larva birth. This could be used as an interesting model to visualize at which step drugs interact with the cell signalling pathway during the ordered developmental process.

Findings: We designed a simple test for screening drugs by investigating simultaneously zygote mitotic division, the progression of embryo development, cell differentiation at early developmental stages and finally organogenesis and population growth rate. We aimed to analyze the toxicology effects of compounds and/or their interference on cellular signalling by examining at which step of the cascade, from zygote to mature embryo, the developmental process is perturbed. We reasoned that a parthenogenetic founder insect, in which the ovarioles shelter numerous embryos at different developmental stages, would allow us to precisely pinpoint the step of embryogenesis in which chemicals act through specific molecular targets as the known ordered homeobox genes.

Conclusion: Using this method we report the results of a genotoxicological and demographic analysis of three compound models bearing in common a bromo group: one is integrated as a base analog in DNA synthesis, two others activate permanently kinases. We report that one compound (Br-du) altered drastically embryogenesis, which argues in favor of this simple technique as a cheap first screening of chemicals or drugs to be used in a number of genotoxicology applications.