Specific activation of the human HSP70 promoter by copper sulfate in mosaic transgenic zebrafish.
Heat shock proteins (HSPs) play a central role in cell protection and repair upon stresses, such as that caused by heat and heavy metals. Copper sulfate inducibility of a pHhsp70 construct expressing the enhanced green fluorescent protein (EGFP) gene under the control of the exogenous human hsp70 promoter was tested in transfected CHSE 214 cells and transgenic zebrafish (Danio rerio). We developed a transient expression system, using mosaically transgenic zebrafish, which allows rapid analysis of transgenic expression. Transfected CHSE 214 cells which had been exposed to 250 nM and 2.5 microM copper sulfate for up to 24h showed increased EGFP expression in a dose-dependent manner. The 1.5 microM copper sulfate caused stronger EGFP fluorescence than the 1.0 microM copper sulfate in transgenic zebrafish. Most of the expression was spotty and was detected in the gills, dorsal and ventral retina, myotubes of the trunk, and skin epithelium. Transgenic zebrafish exposed to copper sulfate exhibited gross dysmorphogenesis, edema and trunk abnormalities, such as spinal lordosis, in vertebral development 5 days after fertilization. This transgenic zebrafish system was sensitive enough to detect copper sulfate at doses below the median lethal concentration (the LC50 was calculated to be 1.2 microM (95% confidence interval of 0.6-1.9 microM)). These results indicate that zebrafish could be useful transgenic biosensor systems for the detection of xenobiotic toxicants in the environment.
Seok
Seung-Hyeok
SH
Department of Laboratory Animal Medicine, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Republic of Korea. lamseok@hanmail.net
Park
Jong-Hwan
JH
Baek
Min-Won
MW
Lee
Hui-Young
HY
Kim
Dong-Jae
DJ
Uhm
Hyung-Min
HM
Hong
Jung-Joo
JJ
Na
Yi-Rang
YR
Jin
Bo-Hwan
BH
Ryu
Doug-Young
DY
Park
Jae-Hak
JH
D000818:Animals; D030801:Animals, Genetically Modified; D002478:Cells, Cultured; D019327:Copper Sulfate / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D009030:Mosaicism; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000502:physiology*; D015027:Zebrafish / Q000502:physiology*
D018840:HSP70 Heat-Shock Proteins; D019327:Copper Sulfate