title: Concentration-response analysis of differential gene expression in the zebrafish embryotoxicity test following flusilazole exposure.
abstract: The zebrafish embryotoxicity test (ZET) is considered a promising alternative model in predictive toxicology. Currently, morphological assessment of the embryo is the main readout for this assay. However, implementation of transcriptomics may help to detect more subtle effects, which may increase the sensitivity and predictability of the test. In this study, we tested a concentration response of flusilazole in the ZET. After exposure for 24 h postfertilization, microarray analysis revealed a number of processes to be regulated in a concentration-dependent way. We identified development related processes, retinol metabolism and transcription, as well as processes corresponding to the antifungal mechanism of action, steroid biosynthesis, and fatty acid metabolism, to be differentially regulated. Retinol metabolism and transcription were already significantly altered at concentrations that were not inducing morphological effects. Differential expression of genes related to steroid biosynthesis and fatty acid metabolism showed a concentration response similar to morphological response. An increase in concentration was also positively associated with an increase in magnitude of expression for individual genes within functional processes. Our study shows that transcriptomics analysis in the ZET is a more sensitive readout of compound-induced effects than morphological assessment. However, the interpretation of differential gene expression in terms of predicting morphological effects is not straightforward and requires further study.
authors.affiliation: Laboratory for Health Protection Research, National Institute for Public Health and the Environment, 3720 BA Bilthoven, The Netherlands. sanne.hermsen@rivm.nl
authors.forename: Sanne A B
authors.initials: SA
authors.lastname: Hermsen
authors.forename: Tessa E
authors.initials: TE
authors.lastname: Pronk
authors.forename: Evert-Jan
authors.initials: EJ
authors.lastname: van den Brandhof
authors.forename: Leo T M
authors.initials: LT
authors.lastname: van der Ven
authors.forename: Aldert H
authors.initials: AH
authors.lastname: Piersma
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology / Q000473:pathology; D000826:Animal Testing Alternatives; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000187:drug effects*; D005659:Fungicides, Industrial / Q000145:classification / Q000633:toxicity*; D015870:Gene Expression / Q000187:drug effects*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000378:metabolism; D012680:Sensitivity and Specificity; D012821:Silanes / Q000145:classification / Q000633:toxicity*; D013723:Teratogens / Q000145:classification / Q000633:toxicity*; D014230:Triazoles / Q000145:classification / Q000633:toxicity*; D015027:Zebrafish
chemical_list: D005659:Fungicides, Industrial; D012333:RNA, Messenger; D012821:Silanes; D013723:Teratogens; D014230:Triazoles; C061365:flusilazole