Radiation Related Gene Expression in Mutants of Bacillus Lentimorbus WJ5 Induced by Gamma Radiation (60Co)

摘要

Ionizing radiation, such as gamma radiation, has a clear mutagenic potential inducing many different types of DNA damages. In order to study the expression of the radiation related genes in mutants induced by gamma radiation, the simultaneous gene expression was analyzed by DNA microarray. Mutants of B. lentimorbus WJ5 were induced by 60Co gamma radiation at the dose of LD_(95) (3.8 kGy). We constructed DNA chips including two thousands of randomly digested genome spots and compared its quantitative aspect with seven mutants (WJ5m4, WJ5ml2, WJ5m16, WJ5m35, WJ5m42, WJ5m63, and WJ5m86). From the cluster analysis of gene expression pattern, totally 408 genes were expressed and 27 genes were significantly upregulated by the gamma radiation in the above all mutants. Especially, genes involved in DNA repair (mutL, mutM), energy metabolism (acsA, sdhB, pgk, yhjB, citB), protease (npr), and reduction response to oxidative stress (HMM) were simultaneously upregulated. It seems that the expression of the repair and resistance related genes in mutants induced by gamma radiation could be remarkably different from that of acute exposure.