Örebro Studies in Life Science 18 I
ÖREBRO 2021 2021ASM
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asmerom seyoum received his Bachelor of Science degree in Marine Biology and Fisheries from University of Asmara, Eritrea, in 2000. He worked as research fellow at the Marine Research Center, Ministry of Fisheries, Massawa, Eritrea from 2000-2004. Asmerom completed his Master of Science in Biology with a specialization in Molecular Medical Bio-logy in 2010 from Örebro University, Sweden. In 2015 he worked as Laboratory engineer at the System Immunology and Microbiology (SIM) research team, Örebro University. Asmerom has been a doctoral student since 2016 at Life Science Research School, School of Science and Technology, Örebro University.
With industrialization, introduction of man-made chemicals to the environ-ment has increased tremendously, raising concern on health and environenviron-mental pollution. To prevent adverse effects of chemicals, regulatory agencies conduct environmental risk assessment (ERA), which is based on toxicological stu-dies. However, traditional toxicological tests are mainly based on observable effects such as organism lethality, immobility, and other overt damages on organisms, and may fail to determine sub-lethal effects. Thus, there is a need for more sensitive techniques to improve ERA.
This thesis describes the usefulness of a qRT-PCR based toxicogenomic analysis in risk assessment. The thesis first investigated effects of three class of organic pollutants i.e. phthalates, perfluoroalkyl substances, and brominated flame retardant using Daphnia magna as a model organism. For these studies both physiological endpoints based classical toxicity test and toxicogenomic (changes in gene expression profile) approaches were employed. The studies demonstrated a strong correlation between physiological responses and re-gulation of genes related to the physiological pathways. This helped to stan-dardized qRT-PCR based toxicogenomic tests. Comparison of toxicogenomic analysis with observed phenotypic endpoints were also able to provide insight to molecular mechanism behind the toxicity of analyzed organic substances. Then, the standardized toxicogenomic analysis was applied to analyze toxicity of environmental samples with sub-lethal pollutant. This thesis provided ad-ditional information on the toxicity of the current in use organic pollutants, which can be useful for regulatory agencies. Overall, the result of this thesis supports the suggestion that qRT-PCR based toxicogenomic analysis can improve ERA. issn 1653-3100 isbn 978-91-7529-365-3
