ZFIN ID: ZDB-PUB-160428-5
Development of a fluorescent transgenic zebrafish biosensor for sensing aquatic heavy metal pollution
Pawar, N., Gireesh-Babu, P., Sabnis, S., Rasal, K., Murthy, R., Zaidi, S.G., Sivasubbu, S., Chaudhari, A.
Date: 2016
Source: Transgenic Research   25(5): 617-27 (Journal)
Registered Authors: Chaudhari, Aparna, Pawar, Nilambari, Sivasubbu, Sridhar
Keywords: Bioreporter, Fluorescent reporter, Metallothionein, Perna viridis, Tol2 transposon vector
MeSH Terms:
  • Animals
  • Animals, Genetically Modified/genetics*
  • Biosensing Techniques/methods*
  • Environmental Monitoring
  • Fluorescence
  • Metallothionein
  • Metals, Heavy/isolation & purification*
  • Metals, Heavy/toxicity
  • Water Pollutants, Chemical/isolation & purification*
  • Water Pollutants, Chemical/toxicity
  • Zebrafish/genetics
PubMed: 27120052 Full text @ Transgenic. Res.
We report a transgenic zebrafish (Danio rerio) designed to respond to heavy metals using a metal-responsive promoter linked to a fluorescent reporter gene (DsRed2). The metallothionein MT-Ia1 promoter containing metal-responsive elements was derived from the Asian green mussel, Perna viridis. The promoter is known to be induced by a broad spectrum of heavy metals. The promoter-reporter cassette cloned into the Tol2 transposon vector was microinjected into zebrafish embryos that were then reared to maturity. A transgene integration rate of 28 % was observed. The confirmed transgenics were mated with wild-type counterparts, and pools of F1 embryos were exposed to sub-lethal doses of Cd(2+), Cu(2+), Hg(2+), Pb(2+) and Zn(2+). The red fluorescence response of zebrafish embryos was observed 8 h post- exposure to these sub-lethal doses of heavy metals using a fluorescence microscope. Reporter expression estimated by real-time PCR revealed eightfold, sixfold and twofold increase on exposure to highest concentrations of Hg(2+), Cd(2+) and Cu(2+), while Pb(2+) and Zn(2+) had no effect. This biosensor could be a first-level screening method for confirming aquatic heavy metal bio-toxicity to eukaryotes.