Zebrafish eye development and function is affected by crude oil exposure – line of evidence from underlying molecular effects to behavioral consequences

bioRxiv (Cold Spring Harbor Laboratory)

Abstract

Abstract Crude oil can affect the normal eye development and swimming behavior of fish embryos. In this study 0-4 hours post fertilization (hpf) zebrafish ( Danio rerio ) embryos were exposed to low, sublethal concentrations of water-accommodated fractions (WAF) of a naphthenic North Sea crude oil alone and in combination with a third-generation chemical dispersant. Effects on eye development and function at the transcript, histological, morphological, and behavioral level were assessed relative to untreated control specimen at 119 hpf. Exposed embryos swam significantly less during the dark phases of the light/dark transition test. Eye size of zebrafish embryos was significantly smaller in groups exposed to crude oil WAFs. Zebrafish retina histology revealed that, among other structural alterations, the outer nuclear layer, containing photoreceptor cells relevant for normal visual functioning, was significantly thinner in exposed embryos. Transcriptome analysis revealed that several genes involved in eye development and function (opsins and crystallins) were dysregulated upon oil exposure. The molecular effects on gene expression and eye histology results form a novel line of evidence that explains the observed effects of crude oil on the swimming activity of exposed fish embryos. The present study is in line with recent findings highlighting the importance of ocular toxicity in developing embryos exposed to petroleum samples at environmentally relevant and non-lethal concentrations without visible malformations. The study suggests that oculotoxicity should be considered as a major toxicity pathway alongside to the well-established cardiotoxicity.

Authors 7

1. Leonie K. Mueller corresponding Aachen Department of Ecosystem Analysis Institute of Environmental Research (Biology V)

   RWTH Aachen University

   Affiliation as printed

   Altertox, Brussels, Belgium

   Department of Ecosystem Analysis, Institute of Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany

   Altertox

   Department of Ecosystem Analysis, Institute of Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University

2. Sarah Johann

   Goethe University Frankfurt

   Affiliation as printed

   Department of Evolutionary Ecology and Environmental Toxicology, Goethe University Frankfurt, Frankfurt am Main, Germany

   Department of Evolutionary Ecology and Environmental Toxicology, Goethe University Frankfurt

3. Bernd Denecke Aachen IZKF Aachen

   RWTH Aachen University · Universitätsklinikum Aachen

   Affiliation as printed

   IZKF Aachen, University Hospital, RWTH Aachen University, Aachen, Germany

   IZKF Aachen, University Hospital, RWTH Aachen University

4. Ali Taleb Abdallah Aachen IZKF Aachen

   RWTH Aachen University · Universitätsklinikum Aachen · University of Cologne · Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases

   Affiliation as printed

   Cluster of Excellence on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany

   IZKF Aachen, University Hospital, RWTH Aachen University, Aachen, Germany

   Cluster of Excellence on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne

   IZKF Aachen, University Hospital, RWTH Aachen University

5. Markus Hecker

   University of Saskatchewan

   Affiliation as printed

   School of the Environment & Sustainability, Toxicology Centre, University of Saskatchewan, Saskatoon, Canada

   School of the Environment & Sustainability, Toxicology Centre, University of Saskatchewan

6. Henner Hollert

   Nanjing University · Goethe University Frankfurt · State Key Laboratory of Pollution Control and Resource Reuse · LOEWE Centre for Translational Biodiversity Genomics · Fraunhofer Institute for Molecular Biology and Applied Ecology

   Affiliation as printed

   Department of Evolutionary Ecology and Environmental Toxicology, Goethe University Frankfurt, Frankfurt am Main, Germany

   Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Department Ecotoxicology across environmental media, Schmallenberg and Frankfurt

   LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberganlage 25, 60325 Frankfurt am Main, Germany

   State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China

   Department of Evolutionary Ecology and Environmental Toxicology, Goethe University Frankfurt

   Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Department Ecotoxicology across environmental media

   LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG)

   State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University

7. Thomas‐Benjamin Seiler Aachen Department of Ecosystem Analysis Institute of Environmental Research (Biology V)

   RWTH Aachen University · Hygiene-Institut des Ruhrgebiets

   Affiliation as printed

   Department of Ecosystem Analysis, Institute of Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany

   Hygiene-Institut des Ruhrgebiets, Gelsenkirchen, Germany

   Department of Ecosystem Analysis, Institute of Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University

   Hygiene-Institut des Ruhrgebiets