However, in recent years more emphasis has been given to the study of invertebrate endocrine system showing that many steroid metabolic pathways are common to the ones of vertebrates and that some of the sex steroids have conserved functions in invertebrates reproduction as well. Further studies are required but our results might indicate a possible mechanism of endocrine Epimedin-B disruption in E. albidus, where steroid and retinol metabolisms were disturbed, producing Bullatine-B imbalanced levels of reproduction hormones. From the uniquely affected transcripts after atrazine exposure, a gene coding for a histone was significantly up-regulated at the EC10. This protein is involved in biological processes related with cell adhesion or the regulation of cell shape and maintenance of DNA integrity. The functions of histones have also been linked to positive regulation of growth rate and larval development, and its enhancement was reported in a study where Caenorhabditis elegans was exposed to atrazine. Some studies with atrazine have also reported disruption on the mitochondrial electron flow. Owen et al. observed significant up-regulation of several transcripts coding for the oxidative phosphorylation pathway in Lumbricus rubellus. The proteomic approach used by Thornton et al. in Drosophila melanogaster exposed organisms also showed significant changes on the mitochondrial protein expressions. In our microarray results, transcripts coding for proteins of the electron transport system were mainly up-regulated after the EC20, confirming the assumption that atrazine affects the normal mitochondrial functioning. Along with carbendazim, atrazine also seems to affect the carbohydrate metabolism by enhancing gluconeogenesis. Both glucan endo-1,3-beta-glucosidase and larval visceral protein d transcripts were up-regulated after carbendazim and atrazine exposures, with validated expression levels by qPCR for the first mentioned transcript. This tendency for increased glucose storage has also been described in a study by Zaya et al. where gene expression coding for glycolysis in Xenopus laevis suggested inhibition of this energetic process. Carbendazim was the only pesticide to induce transcripts encoding for intermediate filament proteins which are involved in DNA ligation during DNA repair. Those transcripts are significantly up-regulated at all carbendazim concentrations suggesting DNA damage and the indication of potential genotoxic effect of this pesticide, even at low concentrations. Effects of carbendazim on reproduction have been attributed to its well known function to interfere with the assembly of microtubules, rather than a mechanism involving endocrine disruption. Our results seem to be in good agreement with that hypothesis. Stathmin 1 oncoprotein 18 and several tubulin transcripts, that are differentially expressed by this compound, code for proteins directly involved in the regulation of cellular proliferation by assembling/disassembling microtubules. Stathmin 1 gene encodes for a cytoplasmic tubulin-binding phosphoprotein that acts to sequester tubulin and favour microtubule disassembly. Disturbances in the normal expression of stathmin correlate with a decreased inactivation of tubulin, a constant microtubule and mitotic spindle assembly and a consequent incapacity to regulate cell cycle progression. For this reason, disturbances in stathmin 1 expression have been associated with several types of cancer. In the present study, the microtubule assembly/disassembly process seems to be affected not only by carbendazim but also by dimethoate.