Quantitative GFP fluorescence as an indicator of arsenite developmental toxicity in mosaic heat shock protein 70 transgenic zebrafish

Toxicol Appl Pharmacol. 2007 Dec 1;225(2):154-61. doi: 10.1016/j.taap.2007.07.011. Epub 2007 Aug 2.


In transgenic zebrafish (Danio rerio), green fluorescent protein (GFP) is a promising marker for environmental pollutants. In using GFP, one of the obstacles which we faced was how to compare toxicity among different toxicants or among a specific toxicant in different model species with the intensity of GFP expression. Using a fluorescence detection method, we first validated our method for estimating the amount of GFP fluorescence present in transgenic fish, which we used as an indicator of developmental toxicity caused by the well-known toxicant, arsenite. To this end, we developed mosaic transgenic zebrafish with the human heat shock response element (HSE) fused to the enhanced GFP (EGFP) reporter gene to indicate exposure to arsenite. We confirmed that EGFP expression sites correlate with gross morphological disruption caused by arsenite exposure. Arsenite (300.0 microM) caused stronger EGFP fluorescence intensity and quantity than 50.0 microM and 10.0 microM arsenite in our transgenic zebrafish. Furthermore, arsenite-induced apoptosis was demonstrated by TUNEL assay. Apoptosis was inhibited by the antioxidant, N-acetyl-cystein (NAC) in this transgenic zebrafish. The distribution of TUNEL-positive cells in embryonic tissues was correlated with the sites of arsenite toxicity and EGFP expression. The EGFP values quantified using the standard curve equation from the known GFP quantity were consistent with the arsenite-induced EGFP expression pattern and arsenite concentration, indicating that this technique can be a reliable and applicable measurement. In conclusion, we propose that fluorescence-based EGFP quantification in transgenic fish containing the hsp70 promoter-EGFP reporter-gene construct is a useful indicator of development toxicity caused by arsenite.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcysteine / pharmacology
  • Animals
  • Animals, Genetically Modified
  • Antioxidants / pharmacology
  • Apoptosis / drug effects
  • Arsenites / administration & dosage
  • Arsenites / toxicity*
  • Biomarkers
  • Dose-Response Relationship, Drug
  • Embryo, Nonmammalian / drug effects
  • Embryo, Nonmammalian / metabolism
  • Environmental Pollutants / administration & dosage
  • Environmental Pollutants / toxicity*
  • Fluorescent Dyes / metabolism*
  • Gene Expression Regulation, Developmental / drug effects
  • Genes, Reporter / drug effects
  • Green Fluorescent Proteins / metabolism*
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism
  • In Situ Nick-End Labeling
  • Mosaicism
  • Zebrafish / genetics


  • Antioxidants
  • Arsenites
  • Biomarkers
  • Environmental Pollutants
  • Fluorescent Dyes
  • HSP70 Heat-Shock Proteins
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • arsenite
  • Acetylcysteine