Publication Abstract

DNA damage in zebrafish larvae induced by exposure to low-dose-rate gamma radiation: Detection by the alkaline comet assay

R.B. Jarvis and J.F. Knowles

This study has determined the sensitivity of the alkaline comet assay for the detection of strand breaks in the DNA of cells taken from a whole organism rather than a single cell type as in previously reported studies. The assay has been performed on material from whole zebrafish larvae irradiated for 1h or 24h at dose rates of of 0.4mGy/hr, 1.2mGy/hr, or 7.2mGy/hr.

Zebrafish larvae exposed to only 1.2mGy/hr of γ-irradiation for 1 hour showed a statistically significant increase in DNA damage compared with controls. This represents a high sensitivity of this animal model for DNA damage and of the comet assay protocol used for detecting such damage. Increasing the exposure time from 1 to 24 hours caused significant increases in DNA damage in zebrafish larvae, although the modest size of these increases in damage for the relatively large increases (24 times) in total absorbed dose indicates that dose rate may be the major factor in determining the level of DNA damage observed under the conditions of these experiments.

Reference:

R.B. Jarvis and J.F. Knowles, 2003. DNA damage in zebrafish larvae induced by exposure to low-dose-rate gamma radiation: Detection by the alkaline comet assay. Mutation Research, 541(1-2): 63-69.