ABSTRACT
Genomic DNA, because of its reactivity, is constantly reacting with environmental chemicals and physical agents, as well as endogenously generated metabolites. The consequences of these reactions can jeopardize the integrity of the genetic information. As cells from most organisms contain only one or a few copies of the genetic information in their chromosome, cells have evolved many defense mechanisms to repair the modified DNA and to maintain the integrity of the genetic information. The importance and the complexity of DNA repair systems is manifested in the fact that more than 100 genes in most organisms code for proteins that are involved in DNA repair mechanisms (1,2).
