Chemical Mutagens : Principles and Methods for Their Detection Volume 1

As editor I want especially to thank Dr. Ernst Freese for helpful co­ operation in preparing these volumes, and to express my appreclatlOn to Drs. Kurt Hirschhorn and Marvin Legator, the other members of the editorial board. Alexander Hollaender January 1971 Preface The purpose of these volumes is to encourage the development and ap­ plication of testing and monitoring procedures to avert significant human exposure to mutagenic agents. The need for protection against exposure to possibly mutagenic chemicals is only now coming to be generally realized. The recently issued Report of the Secretary's Commission on Pesticides and Their Possible Effects on Health (the Mrak Report-U.S. Department of Health, Education and Welfare, December 1969) has made an important start. Its Panel on Mutagenicity recommends that all currently used pesticides be tested for mutagenicity in several recently developed and relatively simple systems. Whether recommendations such as these are actually put into effect will depend on convincing government, industry, and the public that the problem is important, that the proposed tests would be effective, and that they can be conducted at a cost that is not prohibitive. Why is it important to screen environmental agents for mutagenic activity? To those who will read this book, the answer is self-evident. The sine qua non of all that we value and all that we are is our genetic heritage.

of Volume 1.- 1 Molecular Mechanisms of Mutations.- I. Introduction.- II. Causes and Types of Alterations of the Hereditary Material and Protection Against Them.- A. General Causes of Genetic Alterations.- B. Protective Mechanisms.- C. Types of Genetic Alterations.- D. Consequences of Genetic Alterations in Higher Organisms.- III. Detection of Chromosome Aberrations and Systems of Genetic Analysis.- A. Cytological Examination of Large Chromosome Aberrations.- B. Genetic Examination of Mutations.- C. Test Systems for Mammalian Investigations.- IV. Primary DNA Alterations and Their Genotypic and Phenotypic Consequences.- A. Nonhereditary DNA Alterations.- B. Mutagenic DNA Alterations.- C. Inactivating DNA Alterations.- D. Most Agents Induce Several Primary DNA Alterations.- E. Correlation of Agents Inducing Inactivating DNA Alterations with Other Effects.- V. The Effect of Different Agents on DNA and Chromosomes.- A. Incorporation of Base Analogs into DNA.- B. Effect of Nitrous Acid on Resting DNA.- C. Alkylating Agents.- D. N-Nitroso Compounds.- E. Hydroxylamines.- F. Agents Acting after Conversion to Hydroxylamines or Hydroxamates.- G. Other Free-Radical-Producing Agents.- H. Ultraviolet Light.- I. Inhibitors of DNA Synthesis.- J. Intercalating Agents.- K. Metals.- L. Mutator Genes.- VI. References.- 2 Correlation Between Teratogenic and Mutagenic Effects of Chemicals in Mammals.- I. Introduction.- II. Frequency of Effects of Chemicals.- III. Specificity of Action of Chemicals.- IV. Dose.- V. Species, Sex, and Strain Differences.- VI. Timing.- VII. Are Induced Malformations Due to Mutations?.- VIII. Mutagenicity and Teratogenicity Testing.- IX. Conclusion.- X. References.- 3 The Mutagenicity of Chemical Carcinogens: Correlations, Problems, and Interpretations.- I. Introduction.- II. Ultimate Carcinogenic Forms of Chemical Carcinogens Their Reactivities.- A. Alkylating Agents.- B. Potential Alkylating Agents.- C. Aromatic Amines and Amides.- D. 4-Nitroquinoline-1-oxide.- E. N-Hydroxypurines.- F. Polycyclic Aromatic Hydrocarbons.- G. Urethan.- H. N-Nitroso-N-phenylurea.- I. Metal Ions.- J. Conclusion.- III. Mutagenic Activity of Carcinogenic Chemicals.- A. Assay Systems.- B. Problems in Interpretation.- C. Alkylating Agents.- D. Potential Alkylating Agents.- E. Aromatic Amines and Amides.- F. Polycyclic Aromatic Hydrocarbons.- G. Urethan (Ethyl Carbamate).- H. Aflatoxins.- I. Mitomycin C.- J. Hydrazine.- K. Metals.- IV. Conclusions.- V. References.- 4 Effects on DNA: Chemical Methods.- I. Introduction.- II. Isolation of DNA.- III. Degradation of DNA.- A. Enzymatic Methods.- B. Chemical Methods.- IV. Methods of Separation of Products.- A. Chromatography.- B. Electrophoresis.- V. Methods of Detection and Identification of Products.- A. Spectroscopy.- B. Use of Radioactive Materials.- C. Mass Spectroscopy.- VI. References.- 5 Physical-Chemical Methods of the Detection of the Effect of Mutagens on DNA.- I. Introduction.- II. DNA Substrates for Physical Studies.- III. Physical Methods.- IV. Changes Resulting from Alkylation.- V. References.- 6 Effects on DNA: Transforming Principle.- I. Introduction.- II. Biological Systems.- III. Mutagenesis.- A. Kinetics of Mutagenesis.- B. Specificity of Mutagens.- IV. Measuring Mutagenesis.- A. Antibiotic-Resistant Mutants.- B. Reversion of Nutritional Auxotrophs.- C. Use of Closely Linked Genes.- V. Discussion.- VI. Summary Statement.- VII. Experimental Methods.- A. Preparation of Transforming DNA.- B. Biological Assays.- C. Denaturation of DNA.- D. Renaturation of Denatured DNA.- E. Determining the Base Changes in Mutants and Mutations in Transforming DNA.- VIII. Acknowledgments.- IX. References.- 7 Mutagen Screening with Virulent Bacteriophages.- I. Introduction.- II. Bacteriophages as Genetic Systems.- III. Measuring Viral Mutation Rates.- IV. Mutational Pathways.- V. Bacteriophage Screening Systems.- VI. Conclusions.- VII. References.- 8 Prophage Induction in Lysogenic Bacteria as a Method of Detecting Potential Mutagenic, Carcinogenic, Carcinostatic, and Teratogenic Agents.- I. Introduction.- II. General Properties of Lysogenic Bacteria.- III. Induction of Phage Production in Lysogenic Bacteria and Breakdown of the Lysogenic State.- IV. Experimental Prophage Induction Techniques.- A. Inducible Lysogenic Systems.- B. Prophage Induction Assay Techniques.- C. Paper Chromatographic Techniques.- V. Known Prophage Inducing Agents.- A. Historical.- B. Association of Prophage Inducing Capability with Mutagenic, Carcinogenic, Carcinostatic, and Teratogenic Activities.- VI. Prophage Inducing Agents Present in the Human Environment.- VII. Conclusions.- VIII. References.- 9 The Detection of Chemical Mutagens with Enteric Bacteria.- I. Introduction.- II. Discussion.- A. Advantages of Using Bacterial Test Systems for the Detection of Mutagens.- B. Validity of the Bacterial System as a Test for Mutagens and Carcinogens for Humans.- C. Validity of a Negative Result in the Bacterial Test System.- D. Tester Strains.- E. A General Test for Mutagenesis.- F. Agents That Have Been Shown to Be Mutagenic Using These Strains.- G. Phenotypic Curing.- H. Testing of Compounds, Availability of Strains, and Improvements of Procedures.- III. General Methods.- A. Growth of Bacterial Cultures.- B. Pour Plates for Testing Mutagens.- IV. Acknowledgments.- V. References.- Addendum to Chapter 9 Mutagenesis Studies with Escherichia coli Mutants with Known Amino Acid (and Base-Pair) Changes.- I. Introduction.- II. Mutants with Amino Acid Changes in the Tryptophan Synthetase ? Subunit (A Protein).- A. Mutants with Changes at Position 48.- B. Mutants with Changes at Position 210.- C. Mutants with Changes at Position 233.- D. Other Information.- III. References.- 10 Mutation Induction in Yeast.- I. Introduction.- II. General Description of the Organisms.- III. Mutation.- A. Induction and Isolation of Forward Mutants.- B. Characterization of Forward Mutants.- C. Reverse Mutations, Suppressors, and Resistance Mutations.- IV. Mitotic Segregation.- A. Relevance to Mutagen Studies.- B. Detection of Mitotic Segregation.- C. Genetic and Molecular Mechanisms.- D. Experimental Systems for Studying Mitotic Segregation.- E. Relationship Between Reciprocal and Nonreciprocal Mitotic Segregation.- V. Acknowledgments.- VI. References.- Author Index.