PARENT SESSION

Genomic Maintenance & Repair

(PP338) Changes in transcription of selected DNA repair genes induced by exposure of medaka cells to Cd and ionizing radiation.

Moskalenko, Oleksandr^*,1, Grygoryev, Dmytro¹, Zimbrick, John¹, ¹ Environmental and Radiological Health Sciences, Fort Collins, CO, USA

ABSTRACT- It is known that the formation of ionizing radiation-induced DNA damage is modulated by a number of factors such as heavy metal ions. Many of these ions are cytotoxic and carcinogenic. Cadmium (Cd) is a toxic transitional metal that has been recognized as a carcinogen by the International Agency for Research on Cancer. It can affect the activity of cellular DNA repair systems. The biological effects of cadmium are cumulative. We studied cellular responses to single and combined -radiation and Cd exposures via transcriptional profiling of a number of key DNA repair genes using medaka fish (Oryzias Latipes) and medaka embryonic cell culture as model systems. We found changes in expression of a number of key DNA repair genes in treated versus control cells. For example, we find that ogg1, a gene that produces a glycosylase that excises oxidized DNA bases, is upregulated in treated cells. We will present data on the changes in activity of ogg1 and selected other key vertebrate DNA repair genes found in the medaka genome.

Key words: medaka, Cadmium, radiation, DNA