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Time‐course Expression of DNA Repair‐related Genes in Hepatocytes of Zebrafish ( Danio rerio ) After UV‐B Exposure
Author(s) -
Sandrini Juliana Z.,
Trindade Gilma S.,
Nery Luiz Eduardo M.,
Marins Luis F.
Publication year - 2009
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2008.00422.x
Subject(s) - zebrafish , danio , dna repair , dna damage , gene , biology , gene expression , cell cycle , microbiology and biotechnology , dna , genetics
The objective of this study was to evaluate the time‐course effects of UV‐B exposure on expression of genes involved in the DNA repair system of zebrafish ( Danio rerio ) hepatocytes, a highly competent species in terms of damage repair induced by UV radiation. For gene expression analysis (RT‐PCR), cells were exposed to 23.3 mJ cm −2 UV‐B, which was the dose that affected viable cell number (reduction of 30% when compared with the control group) and produced no visual alteration on cell morphology. The early response observed (6 h) showed induction in the expression of the CDKI gene (cyclin‐dependent kinase inhibitor) and genes related to DNA damage repair (mainly XPC and DDB2 ), while the late response observed (24 h) was more related to up‐regulation of p53 and genes involved in cell cycle arrest ( gadd45a , cyclinG1 ). In all times analyzed, the anti‐apoptotic gene Bcl‐2 was down‐regulated. Another interesting result observed was the up‐regulation of the Apex‐ 1 gene after UV‐B exposure, which could indicate the induction of oxidative lesions in the DNA molecule. In conclusion, these results demonstrate an activation of the DNA repair system in hepatocytes of zebrafish exposed to UV‐B radiation, mainly involving the participation of p53.