抄録
Recent knowledge of DNA repair is reviewed in perspective with emphasis on Escherichia coli. Enzymatic phtoreactivation is the simplest and the most general among the three major DNA repair systems. Excision repair is also common from microorganisms to human and yet its molecular mechanism is not universal. Tolerance repair, i.e., post-replication repair, is effective for the widest variety of DNA damage and rather different between lower and higher forms. From these characteristics, it is proposed that DNA repair mechanisms evolved in the order of photoreactivation, excision repair and tolerance repair after the primary living systems were created by solar ultraviolet.
