DNA Ligases/physiology; DNA Repair/physiology; Animals; Bacterial Proteins/genetics; Bacterial Proteins/physiology; CHO Cells/enzymology; Carbon-Oxygen Lyases/physiology; Cell Line; Cell-Free System; Cricetinae; Cricetulus; DNA/chemistry; DNA/drug effects; DNA Adducts; DNA Damage; DNA Glycosylases; DNA Ligases/deficiency; DNA Ligases/genetics; DNA Polymerase beta/physiology; DNA Replication; DNA, Fungal/chemistry; DNA, Fungal/genetics; DNA-(Apurinic or Apyrimidinic Site) Lyase; DNA-Formamidopyrimidine Glycosylase; Deoxyribonuclease IV (Phage T4-Induced); Fibroblasts/cytology; Fungal Proteins/genetics; Fungal Proteins/physiology; Mice; Mice, Transgenic; Models, Genetic; Mutagens/toxicity; N-Glycosyl Hydrolases/physiology; Oxidation-Reduction; Proliferating Cell Nuclear Antigen/physiology; Saccharomyces cerevisiae/genetics