An information-rich alternative, chemicals testing strategy using a high definition toxicogenomics and zebrafish (Danio rerio) embryos

Ashley D. Sawle*, Ernst Wit, Graham Whale, Andrew R. Cossins

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

32 Citations (Scopus)
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Abstract

Large-scale toxicogenomic screening approaches offer great promise for generating a bias-free system-wide view of toxicological effects and modes-of-action of chemicals and ecotoxicants. However, early applications of microarray technology have identified relatively small groups of responding genes with which to define new targets for analysis by conventional means. We have trialled a more intensive approach to the design and interpretation of array experiments incorporating a balanced interwoven ANOVA design with higher levels of biological replication, a more thorough analysis of errors and false discovery rates, and an analysis of response patterns using gene network models. Zebrafish embryos were exposed from 1.5 h post-fertilization for 72 h to ecotoxicants representing different classes-2,4-dichlorophenol, 3,4-dichloroaniline, pentachlorophenol, and cadmium chloride-at low concentrations producing a developmental disturbance to 10% of embryos and half of this dose. Extracted whole embryo RNA was then analyzed on microarrays. Analysis revealed responses of 3000-5000 genes, which is 10-1000 times greater than previously reported, with significance at lower levels of fold change. Some gene responses were common to multiple toxicants, and others were restricted to just one or two toxicants. The gene expression profiles for the different toxicants were distinctive, and analysis using network-based models provided a high level of detail of affected processes, some of which were novel. This approach provides a more highly refined view of toxic effects, from which meaningful patterns of response can be discerned and related to functional deficits and from which more reliable indicators of toxicological effect can be predicted.

Original languageEnglish
Pages (from-to)128-139
Number of pages12
JournalToxicological Sciences
Volume118
Issue number1
DOIs
Publication statusPublished - Nov-2010

Keywords

  • toxicogenomics
  • microarray
  • zebrafish
  • dichloroaniline
  • pentachlorophenol
  • cadmium chloride
  • dichlorophenol
  • FALSE DISCOVERY RATES
  • CELL-CYCLE REGULATION
  • GENE-EXPRESSION
  • BRACHYDANIO-RERIO
  • AQUATIC TOXICITY
  • CADMIUM
  • MICROARRAY
  • ECOTOXICOLOGY
  • RESPONSES
  • SYSTEM

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