Jarvis R B, Knowles J F
The Centre for Environment, Fisheries, and Aquaculture Science, Lowestoft laboratory, Pakefield Road, Lowestoft, Suffolk NR33 OHT, UK.
Mutat Res. 2003 Nov 10;541(1-2):63-9. doi: 10.1016/s1383-5718(03)00182-7.
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 cells from whole zebrafish larvae irradiated for 1 or 24 h at dose rates of 0.4, 1.2 or 7.2 mGy/h. Zebrafish larvae exposed to only 1.2 mGy/h of gamma-radiation for 1h showed a statistically significant increase in DNA damage compared to 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 h 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.
本研究确定了碱性彗星试验在检测取自完整生物体而非如先前报道研究中的单一细胞类型的细胞DNA链断裂方面的敏感性。该试验已在全斑马鱼幼体的细胞上进行，这些幼体以0.4、1.2或7.2 mGy/h的剂量率照射1小时或24小时。与对照组相比，仅以1.2 mGy/h的剂量率暴露于γ辐射1小时的斑马鱼幼体显示出DNA损伤有统计学意义的增加。这表明该动物模型对DNA损伤具有高敏感性，且用于检测此类损伤的彗星试验方案也具有高敏感性。将暴露时间从1小时增加到24小时会导致斑马鱼幼体的DNA损伤显著增加，尽管相对于总吸收剂量相对较大的增加（24倍），这些损伤增加幅度较小，这表明剂量率可能是在这些实验条件下确定观察到的DNA损伤水平的主要因素。
