Transcriptomic responses in mouse blood during the first week after in vivo gamma irradiation

Due to limitations of available human models for development of gene expression based radiation biodosimetry, many such studies have made use of mouse models. To provide a broad view of the gene expression response to irradiation in the mouse, we have exposed male C57BL/6 mice to 0, 1.5, 3, 6 or 10 Gy of gamma rays, sacrificing groups of the mice at 1, 2, 3, 5, or 7 days after exposure. Global gene expression was then profiled in blood from individual mice using Agilent microarrays. In general, we found increasing numbers of genes differentially expressed with increasing dose, with more prolonged responses after the higher doses. Male C57BL/6 mice were either sham irradiated as controls or exposed to 1.5, 3, 6 or 10 Gy of gamma-rays. Mice from each dose group (including controls) were sacrificed at either 1, 2, 3, 5 or 7 days after exposure, and blood collected for microarray analysis. Ten biological replicates, representing independent mice, were done for each dose and time point, with the exception of the 10Gy dose on day 7, for which only 8 replicates were obtained.