Chemical Mutagens : Principles and Methods for Their Detection

Volume 9 of Chemical Mutagens consists mainly of chapters discussing the development and validation of short-term assays to detect the mutagenic effects of environmental chemicals. These chapters include an assay with the grasshopper neuroblast, a comparison of mutagenic responses of human lung-derived and skin-derived diploid fibroblasts, a forward-mutation assay in Salmonella, a multigene sporulation test in Bacillus subtilis, a specific locus assay in mouse lymphoma cells, a study of the induction of bacteriophage lambda, and the granuloma pouch assay. In addition, there are two chapters on the identification of mutagens in cooked food and in human feces. Frederick 1. de Serres Research Triangle Park, North Carolina vii Contents Chapter 1 The Grasshopper Neuroblast Short-Term Assay for Evaluating the Effects of Environmental Chemicals on Chromosomes and Cell Kinetics 1 Mary Esther Gaulden, Jan C. Liang, and Martha J. Ferguson 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Embryo Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. 1. Species. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. 2. Origin of Colonies . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. 3. Life Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. 4. Colony Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 6 2. 5. Pathology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. 6. Allergy to Grasshoppers . . . . . . . . . . . . . . . . . . . . . . 14 3. Grasshopper Egg, Embryo, and Cells . . . . . . . . . . . . . . . . . 14 3. 1. The Egg Shell and Membranes . . . . . . . . . . . . . . . . . 14 3. 2. Embryonic Development . . . . . . . .. . . . . . . . . . . . . . 17 3. 3. Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4. Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4. 1. Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4. 2. Preparation of Embryos for Cell Analysis . . . . . . . . . 34 4. 3. Analysis of Mutagen Effects. . . . . . . . . . . . . . . . . 40 . . . 5. Response of the Grasshopper Neuroblast to Mutagens . . . . 50 5. 1. Reproducibility of Data . . . . . . . . . . . . . . . . . . . . . . . 50 5. 2. Radiation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 5. 3. Chemical Mutagens . . . . . . . . . . . . . . . . . . . . . . . . . .

1 In Vivo Mutagenicity Testing Using Somatic Cells of Drosophila melanogaster.- 1. Introduction.- 2. Basic Developmental Biology of Drosophila.- 3. The Wing Mosaic System.- 3.1. The Genetic Basis of the Wing System.- 3.2. Scoring.- 3.3. Data Analysis.- 3.4. Spontaneous Frequencies of Spots in Different Genetic Backgrounds.- 4. The White/White-Coral Eye Mosaic System.- 4.1. The Genetic Basis of the White/White-Coral System.- 4.2. Scoring.- 4.3. Data Analysis.- 4.4. Background Frequencies of Spots.- 5. The Unstable White-Zeste Eye Mosaic System.- 5.1. The Genetic Basis of the Unstable White-Zeste System.- 5.2. Scoring.- 5.3. Data Analysis.- 5.4. Background Frequencies of Spots.- 5.5. Mechanism.- 6. Exposure Techniques.- 6.1. Egg Collection.- 6.2. Collection of Larvae.- 6.3. Feeding.- 6.4. Inhalation.- 6.5. Injection.- 6.6. Solvents.- 6.7. Dosimetry.- 7. Discussion.- 7.1. Genetic Mechanisms.- 7.2. Differences between Genotypes.- 7.3. Toxic Effects and Cell Death.- 7.4. Status of Validation.- 7.5. Comparison of Germ Cells versus Somatic Cells.- 7.6. Comparison of Drosophila Tests with Other Assay Systems.- 7.7. Future Developments.- 7.8. Test Performance.- 8. Conclusions.- 9. References.- 2 Structural and Metabolic Parameters Governing the Mutagenicity of Polycyclic Aromatic Hydrocarbons.- 1. Introduction.- 1.1. Scope of This Review.- 1.2. Terms, Short Names, and Abbreviations.- 1.3. Overview of the Metabolism of PAHs in Mammals.- 2. Activation Pathways of PAHs.- 2.1. Requirement of Activation for Mutagenicity to Occur.- 2.2. Activation to Monofunctional Epoxides.- 2.3. Activation to Vicinal Diol-Epoxides.- 2.4. Activation to Benzylic Esters.- 2.5. Activation to Free Radicals.- 2.6. Other Activation Pathways.- 3. Contribution of Different Activation Pathways to the Mutagenicity of PAHs.- 3.1. DNA Adducts.- 3.2. Modified Test Compounds to Elucidate the Activation Process.- 3.3. Use of Diagnostic Enzymes and Enzyme Inhibitors.- 4. Metabolic Control of Mutagenic Intermediates of PAHs.- 4.1. Mutagenicity Experiments with Subcellular Metabolizing Systems.- 4.2. Mutagenicity Experiments Using Intact Cells as the Metabolizing Systems.- 5. Summary and Conclusions.- 6. Addendum: Recent Developments.- 6.1. Mutagenicity of Quinones.- 6.2. Mutagenicity of Phenol-diol-epoxides.- 7. References.- 3 Chromosomal Mutations: The Genetic Approach.- 1. Introduction.- 2. The Main Categories of Chromosomal Mutation.- 2.1. Numerical Anomalies.- 2.2. Structural Anomalies.- 3. Genetic Detection of Aneuploidy in the Mouse.- 3.1. Sex-Chromosomal Aneuploidy.- 3.2. Autosomal Aneuploidy.- 4. Reciprocal Translocations: Detection and Analysis.- 4.1. Translocations in Specific Locus Tests.- 4.2. Heritable Translocation Assays.- 4.3. Genetic Analysis of Reciprocal Translocations and Their Products.- 5. Detection and Study of Other Translocations and of Inversions.- 5.1. Robertsonian Translocations.- 5.2. Insertions.- 5.3. Inversions.- 6. Detection and Study of Deletions.- 6.1. X-Chromosomal Deletions.- 6.2. Autosomal Deletions.- 7. Conclusions.- 8. References.- 4 Cytogenetic Assays for Mitotic Poisons Using Somatic Animal Cells.- 1. Introduction.- 2. Mitotic Poisons and Their Genomic Effects.- 2.1. The Spindle Apparatus.- 2.2. The Centriole.- 2.3. Kinetochores.- 2.4. Cytokinesis.- 3. Assays with Diploid Mammalian Cells in Vitro.- 3.1. Choice of Cell Lines.- 3.2. Mitotic Arrest.- 3.3. Recovery Experiments.- 3.4. Aneuploidy Enumeration.- 3.5. Slide Reading.- 4. Assays with Bone Marrow Cells in Vivo.- 4.1. Animals.- 4.2. Techniques.- 5. Assays with Grasshopper Embryos.- 5.1. Test Materials.- 5.2. General Information about Grasshopper Embryos.- 5.3. Procedure.- 6. Conclusions.- 7. References.- 5 Detection of Aneuploidy in Drosophila.- 1. Introduction.- 1.1. Role of Drosophila.- 1.2. Definition of Aneuploidy.- 2. Issues.- 2.1. Sex.- 2.2. Germ Cell Stage.- 2.3. Other Factors.- 3. Assay Systems.- 3.1. Classical Test.- 3.2. Selective and Semi selective Tests.- 4. Known Positives.- 4.1. Colchicine.- 4.2. Methyl Mercury Hydroxide.- 4.3. Inhibitors of Nucleic Acid Synthesis.- 5. Summary.- 6. References.- 6 Mammalian Cytogenetic and Genetic Tests for Nondisjunction.- 1. Introduction.- 2. Cytogenetic Tests.- 2.1. Methods Using Primary and Secondary Gametocytes.- 2.2. Methods Using Spermatids and Spermatozoa.- 2.3. Methods Using Pre- and Postimplantation Embryos.- 3. Genetic Test Systems with the Mouse.- 3.1. The Numerical Sex-Chromosome Anomaly (NSA) Method.- 3.2. Tests Using Robertsonian Translocations.- 4. Summary and Conclusions.- 5. References.- 7 Using Repair-Deficient Chinese Hamster Ovary Cells to Study Mutagenesis.- 1. Introduction.- 2. Genetic and Biochemical Properties of Repair-Deficient Mutants.- 2.1. Complementation Groups of UV-Sensitive Mutants.- 2.2. Defective Excision Repair in UV-Sensitive Mutants.- 2.3. Defective Strand-Break Repair in Mutant EM9.- 2.4. Elevated Sister Chromatid Exchange in Mutant EM9.- 2.5. Complementation of CHO Mutations by Human Genes.- 3. Hypersensitivity of Repair Mutants to DNA-Damaging Agents.- 3.1. Sensitivity Determined by Colony Formation.- 3.2. Methodology for Measuring Mutations.- 3.3. Sensitivity to Mutation Induction.- 4. Rapid Detection of DNA-Damaging Agents by Differential Cytotoxicity (DC).- 4.1. Concept and Methodology of DC Assay.- 4.2. Response of Repair-Deficient Lines to Nonmutagens.- 4.3. Response of Repair-Deficient Lines to Monofunctional Bulky Mutagens.- 4.4. Response of Repair-Deficient Lines to Bifunctional Bulky Mutagens.- 4.5. Response of Mutants EM9 and UV-1 to Methylating and Ethylating Agents.- 4.6. Response of Mutant UV-1 to Various Other Agents.- 4.7. Response of DC Assay to Alkylation Congeners.- 4.8. DNA-Damaging Agents Not Detected by the DC Assay.- 4.9. Merits and Limitations of the DC Assay.- 5. Conclusions.- 6. References.- 8 Transplacental Genotoxic Agents: Cytogenetic Methods for Their Detection.- 1. Introduction.- 2. Animal Studies.- 2.1. Metaphase Analysis.- 2.2. Micronuclei.- 2.3. Sister Chromatid Exchange.- 2.4. Maternal-Fetal Comparisons.- 2.5. Cell and Tissue Specificity.- 2.6. Detection of Transplacental Carcinogens and Teratogens.- 2.7. General Comments on Animal Studies.- 3. Human Studies.- 3.1. Risk Factors in Childhood Cancers and Congenital Malformations.- 3.2. Choice of Cell Types and Assay Systems.- 3.3. Results of Population Monitoring.- 4. References.- 9 Computer Automation of Metaphase Finding, Sister Chromatid Exchange, and Chromosome Damage Analysis.- 1. Introduction.- 1.1. Value of Short-Term Cytogenetic Tests for Mutagenesis Testing.- 1.2. Need for High-Speed Automated Cytogenetic Analysis.- 2. Historical Trends in Computer Automation.- 2.1. Metaphase Finding and Karyotyping.- 2.2. Automated Chromosome Aberration and Sister Chromatid Exchange Scoring.- 3. Development of a System for Cytogenetic Mutagenicity Testing.- 3.1. Early Approaches.- 3.2. Image Analysis Configuration.- 3.3. Program Operation.- 4. Future Prospects for Full Automation.- 5. References.- 10 Mutagen-Sensitive Mutants and Chemical Mutagenesis in Drosaphila.- 1. Introduction.- 2. Isolation and Localization of Mutants.- 3. Biochemical Characteristics.- 3.1. Introduction.- 3.2. Photoreactivation.- 3.3. Excision Repair.- 3.4. Postreplication Repair.- 4. Larval Exposure.- 4.1. Spontaneous Mutations.- 4.2. Direct-Acting Mutagens.- 4.3. Promutagens.- 5. Adult Exposure.- 5.1. Spontaneous Mutations.- 5.2. Direct-Acting Mutagens.- 5.3. Promutagens.- 6. Maternal Effects.- 6.1. Spontaneous Mutations.- 6.2. Direct-Acting Mutagens.- 6.3. Promutagens.- 6.4. The Assay with st mus(3)302 Females.- 6.5. Statistics.- 7. Storage Effect.- 8. Conclusions.- 9. References.- 11 Chromosomal Causes for Fertility Reduction in Mammals.- 1. Introduction.- 2. Numerical Chromosome Mutations of the Sex Chromosomes and Related Conditions.- 2.1. Sex-Chromosome Anomalies in the Male.- 2.2. Sex-Chromosome Anomalies in the Female.- 3. Structural Chromosome Anomalies.- 3.1. Reciprocal Translocations between the Autosomes.- 3.2. Robertsonian Translocations.- 3.3. Inversions.- 3.4. Duplications and Deficiencies.- 4. Combinations of Chromosome Mutants within One Carrier.- 4.1. Two Reciprocal Translocations That Have No Chromosomes in Common.- 4.2. Two Reciprocal Translocations That Have One Chromosome in Common.- 4.3. Two Reciprocal Translocations That Have Two Chromosomes in Common.- 4.4. Combinations of Robertsonian Translocations That Have No Arms in Common.- 4.5. Combinations of Two Robertsonian Translocations That Have One Chromosome in Common.- 4.6. Combinations of Robertsonian and Reciprocal Translocations.- 4.7. The Combination of Two Paracentric Inversions within the Same Chromosome.- 5. Viable Unbalanced Progeny Obtained from Translocation Heterozygote Females and Males.- 6. Why is Chromosomal Infertility More Clearly Expressed in the Male Than in the Female? Consideration of X-Autosome Translocations.- 7. References.- 12 Mutagenesis and Plasmids.- 1. Introduction.- 2. Historical Overview of Plasmids.- 2.1. Colicin Plasmids.- 2.2. Resistance Transfer Plasmids (R Plasmids).- 2.3. Plasmid Compatibility.- 2.4. Plasmid Replication.- 2.5. Plasmid Size.- 2.6. DNA Damage and Plasmids.- 2.7. Spontaneous Mutagenesis and Plasmids.- 3. Survey of Thirty-Three R Plasmids.- 3.1. Materials and Methods.- 3.2. Results.- 3.3. Discussion.- 4. Mechanisms of Plasmid-Mediated Effects on Mutagenesis and Survival.- 4.1. Genetic Studies.- 4.2. Biochemical Studies.- 4.3. Molecular Studies.- 4.4. One versus Several Mechanisms.- 5. References.- 13 Mutation in Somatic Cells as Determined by Electrophoretic Analysis of Mutagen-Exposed Chinese Hamster Ovary Cells.- 1. Introduction.- 1.1. Characterization of Electrophoretic Mutations in Natural Populations.- 1.2. Rationale for Isolation of Electrophoretically Detectable Mutations.- 2. Methods of Procedure.- 2.1. Isolation of Clones Exposed to Mutagens.- 2.2. Electrophoretic Detection of Mutations at Enzyme Loci.- 2.3. Mutant Criteria.- 3. Results and Discussion.- 3.1. Loci at Which Mutations Were Obtained.- 3.2. Functional Ploidy in CHO Cells and Its Effect on Mutation Frequency.- 3.3. Mutation Frequency in Mammalian Somatic Cells.- 4. Summary.- 5. References.