The Difference Of Genes Expression Induced By Ionizing Radiation Between IRM-2 Mice And Their Parental Mice

IRM-2 mice are new inbred mice that are reproducted by our institution . Their outstanding characteristics are of high radioresistance and low chromosomal aberration. The radiosensitivity cell lines or mutants are used to study the role of radioresistance indirectly in the radioresistance studies at present. Comparatively, as IRM-2 mice are of radioresistance, the role of DNA damage caused by radiation and damage repair can be observed directly invivo. Our goal is to investigate the radioresistance mechanism of IRM-2 mice through measuring the differences of DNA single strand break and double strands break and their repair and mRNA expression of XRCC1, XRCC5 , caspase-3 and survivin genes between IRM-2 mice and their parental mice ICR/JCL and 615 mice .The study includes three sections:1 DNA damage and damage repair of spleen cells in mice induced by postirradiation using pulsed-field gel electrophoresis2 the mRNA expression of XRCC1 and XRCC5 genes in mice induced by postirradiation by northern blot assay3 the mRNA expression of caspase-3 and survivin genes in mice induced by postirradiation. with RT-PCRResults:1 DNA damage and damage repair1.1 DNA damageThe initial DNA damages of unradiation IRM-2 mice are lower, ie the quantities of DSB and SSB in IRM-2 mice are lower than that of their parental mice ICR/JCL and 615 mice ( P<0.01 ) .The percentage of DSB and SSB in IRM-2 mice are lower than that of ICR/JCL...