Abstract
Prenatal exposure to ionizing radiation of low doses in rodents induces deceleration of neuronal migration during cortical histogenesis. On the contrary, exposure to carbon beams during fetal period mainly affects cell survival. However, the molecular mechanisms underlying such difference in the effects between exposure to carbon beams and exposure to X-rays remain unknown. As the first step to shed light on the underlying mechanisms, we have attempted to elucidate whether the changes of gene expression after exposure to heavy ions differ from those after X-rays in fetal brains. Rab6A and its effector protein Rab-KIFL, involved in Golgi-to-endoplasmic reticulum retrograde transport, were found as the gene showing up-regulation in X-irradiated fetal brain. The changing pattern of expression of these genes was different between brains exposed to heavy-ion beams and those to X-rays. We report here the comparison of dose-dependent and temporal changes of mRNA expression of these genes in cell lines (Neuro2a, NIH/3T3) between exposure to carbon beams and exposure to X-rays.