Section I Reviews.- 1 Relationship Between Repair Processes and Mutation Induction in Bacteria.- 2 Role of Cellular Systems in Modifying the Response to Chemical Mutagens.- 3 DNA Repair Pathways.- Section II Lower Eukaryotes.- A. Neurospora crassa.- 4 Mutagen-Sensitive Mutants in Neurospora.- 5 Nucleases and Their Control in Wild-Type and nuh Mutants of Neurospora.- 6 Mutation-Induction in Repair-Deficient Strains of Neurospora.- B. Saccharomyces cerevisiae.- 7 Genetic and Physiological Factors Affecting Repair and Mutagenesis in Yeast.- 8 Molecular Mechanism of Pyrimidine Dimer Excision in Saccharomyces cerevisiae. I. Studies with Intact Cells and Cell-Free Systems.- 9 Genetic Analysis of Error Prone Repair Systems in Saccharomyces cerevisiae.- 10 DNA Repair and Mutagen Interaction in Saccharomyces: Theoretical Considerations.- 11 Repair and Mutagenesis in Lower Eukaryotes: A Summary and Perspective.- Section III Drosophila.- 12 Isolation and Characterization of Repair-Deficient Mutants of Drosophila melanogaster.- 13 Effects of Recombination-Deficient and Repair-Deficient Loci on Meiotic and Mitotic Chromosomes Behavior in Drosophila melanogaster.- 14 Biochemical Characterization of Repair-Deficient Mutants of Drosophila.- 15 Mutation Induction in Repair-Deficient Strains of Drosophila.- 16 Repair and Mutagenesis in Drosophila: A Summary and Perspective.- Section IV Mammalian Somatic Cells.- 17 Relationship of DNA Lesions and Their Repair to Chromosomal Aberration Production.- 18 Relationship of DNA Repair and Chromosome Aberrations to Potentially Lethal Damage Repair in X-irradiated Mammalian Cells.- 19 Chromosome Aberration Formation and Sister Chromatid Exchange in Relation to DNA Repair in Human Cells.- 20 DNA Repair Process Can Alter the Frequency of Mutations Induced in Diploid Human Cells.- 21 Ultraviolet Light Induction of Diphtheria Toxin-Resistant Mutations in Normal and DNA Repair-Deficient Human and Chinese Hamster Fibroblasts.- 22 Mutation Induction in a Radiation-Sensitive Variant of Mammalian Cells.- 23 Repair of Human DNA in Molecules that Replicate or Remain Unreplicated Following Ultraviolet Irradiation.- 24 DNA Repair in Nuclei Isolated from HeLa Cells.- 25 Repair and Induction of Chromosome Aberrations and Point Mutations in Mammalian Somatic Cells: A Summary and Perspective.- Section V Mouse Germ Cells.- 26 Relationship Between Unscheduled DNA Synthesis and Mutation Induction in Male Mice.- 27 Radiation- and Drug-Induced DNA Repair in Mammalian Oocytes and Embryos.- 28 Repair in Fertilized Eggs of Mice and its Role in the Production of Chromosomal Aberrations.- 29 Repair and Mutation Induction in Mouse Germ Cells: A Summary and Some Thoughts.- Section VI Relevance to Human Health Hazard Assessment.- 30 The Chromosome-Breakage Syndromes: Different Genes, Different Treatments, Different Cancers.- 31 Summary and Perspective: Relevance to Human Health Hazard Assessment.- Contributors.