Responses To Iron Oxide And Zinc Oxide Nanoparticles In Echinoderm Embryos And Microalgae: Uptake, Growth, Morphology, And Transcriptomic Analysis

We investigated the toxicity of Iron oxide and Zinc oxide engineered nanoparticles (ENPs) onParacentrotus lividussea urchin embryos and three species of microalgae. Morphological responses, internalization, and potential impacts of Fe(2)O(3)and ZnO ENPs on physiology and metabolism were assessed. Both types of ENPs affectedP. lividuslarval development, but ZnO ENPs had a much stronger effect. While growth of the algaMicromonas commodawas severely impaired by both ENPs,Ostreococcus tauriorNannochloris sp.were unaffected. Transmission electron microscopy showed the internalization of ENPs in sea urchin embryonic cells while only nanoparticle interaction with external membranes was evidenced in microalgae, suggesting that marine organisms react in diverse ways to ENPs. Transcriptome-wide analysis inP. lividusandM. commodashowed that many different physiological pathways were affected, some of which were common to both species, giving insights about the mechanisms underpinning toxic responses.